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Walking in Minimalist Shoes Is Effective for Strengthening Foot Muscles
Abstract
Introduction:
Weakness of foot muscles may contribute to a variety of loading-related injuries. Supportive footwear may contribute to intrinsic foot muscle weakness by reducing the muscles' role in locomotion (e.g., absorbing forces and controlling motion). Increased stimulus to the foot muscles can be provided through a variety of mechanisms, including minimalist footwear and directed exercise.
Purpose:
To determine the effect of walking in minimalist footwear or performing foot strengthening exercises on foot muscle size and strength.
Methods:
Fifty-seven runners were randomly assigned to one of three groups-minimalist shoe walking (MSW), foot strengthening (FS) exercise, or control (C). All groups maintained their prestudy running mileage throughout the study. The MSW group walked in provided footwear, increasing weekly the number of steps per day taken in the shoes. The FS group performed a set of progressive resistance exercises at least 5 d·wk. Foot muscle strength (via custom dynamometers) and size (via ultrasound) were measured at the beginning (week 0), middle (week 4), and end (week 8) of the study. Mixed model ANOVA were run to determine if the interventions had differing effects on the groups.
Results:
There were significant group-time interactions for all muscle size and strength measurements. All muscle sizes and strength increased significantly from weeks 0 to 8 in the FS and MSW groups, whereas there were no changes in the C group. Some muscles increased in size by week 4 in the FS and MSW groups.
Conclusions:
Minimalist shoe walking is as effective as foot strengthening exercises in increasing foot muscle size and strength. The convenience of changing footwear rather than performing specific exercises may result in greater compliance.
... After the rst week, all participants were contacted via telephone to answer any potential questions and improve training compliance. If participant's in the MS group reported no adverse events or negative side effects (i.e., pain), they were subsequently requested to increase their daily step count to 5,000 11 . Participants of the MS group tracked the amount of steps taken in MS shoes during the intervention period via smartphone app (Accupedo, Corusen, USA) and documented them via web-based training software (Lanista, MP Sports, Coaching & Consulting GmbH, GER). ...
... Nevertheless, it must be noted that there seems to be a difference between walking and running in MS, as walking probably requires the foot to go through a greater ROM, because of potential heel to toe walking, rather than mid-or forefoot striking during running 11 . Yet, no ROM changes, neither locally in the foot nor other DC areas, were found in our study. ...
... Although studies frequently reported the positive effects of MS on IFM strength 4,8,11,17 , little is known about the in uence of MS on motor performance (i.e., sports) in general and more speci cally about muscle strength of the DC 22 . We assessed this with three different tests, addressing either isolated structures (i.e., hamstrings) or more composite measures of strength of the DC. ...
Research suggests that running in minimalist shoes (MS) positively influences local and non-directly adjacent areas of the dorsal chain (DC). This study investigates the effects of 4-week MS walking in non‑runners.
28 healthy participants (15f, 13m; 25.3 ± 5.3 yrs; 70.2 ± 11.9 kg; 175.0 ± 7.8 cm) were randomly assigned to a control or intervention group. The intervention group undertook a 4‑week incremental walking program in MS, which included a daily step count of 3,000 steps/day in the first week increasing to 5,000 steps/day for the remaining 3 weeks. The control group walked in their preferred shoe (no MS). We assessed the following parameters in a laboratory at baseline [M1], and after the 4-week intervention [M2]: Foot parameters (e.g. FPI‑6), lower limb ROM, balance during single-leg stance, and muscle strength of the DC. For statistical analysis, stepwise linear regression models in forward selection were calculated.
In the MS group, the FPI-6 (b = -3.72, t(51) = -6.05, p < .001, [-4.94, 2.51]) and balance (b = -17.96, t(49) = -2.56, p = .01, [-31.54, 4.37]) significantly improved from M1 to M2, but not all other parameters (all p >.05).
Walking with MS might be an advantageous intervention for non-runners.
... have fewer foot and toe deformities and defects [27] as well as higher arch heights [28,29] compared to conventionally shod runners. Similarly, some individual studies have reported statistically significant improvements in IFM strength [1,30,31] and size [14,17,31,32] due to the usage of minimalist shoes. However, a systematic review to understand these changes in IFM strength or size has not yet been performed. ...
... have fewer foot and toe deformities and defects [27] as well as higher arch heights [28,29] compared to conventionally shod runners. Similarly, some individual studies have reported statistically significant improvements in IFM strength [1,30,31] and size [14,17,31,32] due to the usage of minimalist shoes. However, a systematic review to understand these changes in IFM strength or size has not yet been performed. ...
... All 9 articles were assessed with the PEDro scale. Six of the studies were considered good with PEDro scores ranging from 6-7 [1,14,16,17,31,35], and 3 studies were considered fair with PEDro scores ranging from 4-5 [30,36]. ...
Minimalist shoes are proposed to prevent injury and enhance performance by strengthening intrinsic foot muscles, yet there is little consensus on the effectiveness of minimalist shoes in increasing their strength or size. This systematic review assesses using minimalist shoes as an intervention on changes in plantar intrinsic foot muscle size and strength. PubMed, CINHAL, Scopus, and SPORT Discus were systematically searched for articles between January 2000 to March 2022. Studies were included if they had an intervention of at least 2 weeks with a control group and examined the effect of minimalist shoes on plantar intrinsic foot strength or size (either volume, or cross-sectional area, or thickness). 9 studies were included. There were significant increases and percent changes in foot muscle strength, volume, cross-sectional area, and thickness. Strength increased between 9%-57%, and size increased between 7.05%-10.6%. Minimalist shoes may effectively increase intrinsic foot muscle size and strength in healthy individuals, and they may also be more convenient than implementing time-intensive physical therapy programs. Future research is needed to explore using minimalist shoes as an intervention for clinical populations who would benefit from increased IFM strength and function. It will also be vital to improve upon IFM assessment methods.
... Therefore, measuring flexor strength of plantar foot muscles in units of force is restricted to measuring net toe flexor or toe grip force produced by the PIFMs in conjunction with the extrinsic foot muscles [16]. To overcome this limitation, ultrasound has been applied to study individual foot muscles (i.e., both intrinsic and extrinsic) [17][18][19]. This imaging technique is used to obtain the dimensions of these muscles, as an estimate of its capacity to exert force. ...
... Although ultrasonography has been shown to be a reliable instrument to measure quadriceps and gastrocnemius morphology in older adults [43], this is still unknown for the foot muscles. These muscles, including the PIFMs, extrinsic toe flexor muscles, but also extrinsic in-and evertors, should be jointly assessed together with the plantar fascia (PF), considering the synergistic contribution of this group of foot tissues to foot function [17][18][19]. The reliability of ultrasonography to assess the morphology for these foot muscles and the PF needs to be determined in order to judge the potential of this instrument to be used in future research concerning, for instance, the role of the foot muscles in relation to fall risk-related mobility parameters. ...
... In order to be a meaningful metric to measure a group mean change in muscle morphology, for example in a prospective intervention study, this change should exceed the SDC divided by the square root of the sample size [50]. A group change of this magnitude is realistic as an 8-week foot strengthening intervention in younger adults showed average foot muscle hypertrophy ranging from 5 to 15% [17] and, in general, older adults are expected to have a similar response to strength training [51]. Whether the morphological changes of foot muscles as a response to training in older adults indeed exceed the SDCs, needs to be investigated in future studies. ...
Background
To gain insight into the role of plantar intrinsic foot muscles in fall-related gait parameters in older adults, it is fundamental to assess foot muscles separately. Ultrasonography is considered a promising instrument to quantify the strength capacity of individual muscles by assessing their morphology. The main goal of this study was to investigate the intra-assessor reliability and measurement error for ultrasound measures for the morphology of selected foot muscles and the plantar fascia in older adults using a tablet-based device. The secondary aim was to compare the measurement error between older and younger adults and between two different ultrasound machines.
Methods
Ultrasound images of selected foot muscles and the plantar fascia were collected in younger and older adults by a single operator, intensively trained in scanning the foot muscles, on two occasions, 1–8 days apart, using a tablet-based and a mainframe system. The intra-assessor reliability and standard error of measurement for the cross-sectional area and/or thickness were assessed by analysis of variance. The error variance was statistically compared across age groups and machines.
Results
Eighteen physically active older adults (mean age 73.8 (SD: 4.9) years) and ten younger adults (mean age 21.9 (SD: 1.8) years) participated in the study. In older adults, the standard error of measurement ranged from 2.8 to 11.9%. The ICC ranged from 0.57 to 0.97, but was excellent in most cases. The error variance for six morphology measures was statistically smaller in younger adults, but was small in older adults as well. When different error variances were observed across machines, overall, the tablet-based device showed superior repeatability.
Conclusions
This intra-assessor reliability study showed that a tablet-based ultrasound machine can be reliably used to assess the morphology of selected foot muscles in older adults, with the exception of plantar fascia thickness. Although the measurement errors were sometimes smaller in younger adults, they seem adequate in older adults to detect group mean hypertrophy as a response to training. A tablet-based ultrasound device seems to be a reliable alternative to a mainframe system. This advocates its use when foot muscle morphology in older adults is of interest.
... We hypothesize that low intensity activities of daily living (such as walking) in minimal footwear might increase foot strength too. Ridge et al. 36 found that runners walking in minimal footwear for eight weeks increased their foot muscle strength. Holowka et al. 37 found that the intrinsic foot muscles, abductor hallucis and abductor digiti minimi, were larger in a habitually minimally shod population than in a habitually conventionally western shod population. ...
... The key finding of this study is that wearing minimal shoes for six months, even for non-intensive daily activities, increases toe flexion strength by 57.4% in a general population (Fig. 3). This is in alignment with the research by Ridge et al. 36 , who studied experienced runners and observed an 41% increase after eight weeks of walking in minimal footwear. We used an extended period of six months, and also compared the results from this intervention study with those of long-time minimal footwear users. ...
... It should be noted that the TFS we measured is most likely a combination of both intrinsic and extrinsic foot muscles, but both share several functions 29 . We have not used MRI or ultrasound imaging to quantify the size of individual muscles 36,37 . Figure 4 shows that previously Western adults with at least six months experience in minimal footwear have greater TFS per unit mass than their peers with no minimal footwear experience. ...
The human foot is uniquely adapted to bipedal locomotion and has a deformable arch of variable stiffness. Intrinsic foot muscles regulate arch deformation, making them important for foot function. In this study we explore the hypothesis that normal daily activity in minimal footwear, which provides little or no support, increases foot muscle strength. Western adults wore minimal footwear for a six-month period (the “intervention” group). Foot strength, i.e., maximum isometric plantarflexion strength at the metatarsophalangeal joints, and foot biometrics were measured before and after the intervention. An additional group was investigated to add further insight on the long-term effects of footwear, consisting of Western adults with an average 2.5 years of experience in minimal footwear (the “experienced” group). This study shows that foot strength increases by, on average, 57.4% (p < 0.001) after six months of daily activity in minimal footwear. The experienced group had similar foot strength as the post intervention group, suggesting that six months of regular minimal footwear use is sufficient to gain full strength, which may aid healthy balance and gait.
... This is likely due to the greater demand placed on these muscles when walking in unsupportive footwear. Other studies have shown foot muscles hypertrophy when transitioning to minimal footwear for walking (74). A recent study reported that an 8 week, progressive walking program in minimal shoes increased intrinsic and extrinsic muscle size and strength [10]. ...
... Similar to bone injuries, it is possible that many of the muscle strains or soreness injuries could be prevented by a slow increase in activity in minimal footwear. A foot core program (87), has been shown to significantly increase the size and strength of the intrinsic and extrinsic foot muscles (74,88). The addition of such a program can also help prepare the foot for the transition and reduce injury risk during this period. ...
... Diabetic neuropathy has been shown to affect both the intrinsic and extrinsic muscles of the foot (169)(170)(171)(172)(173)(174). The intrinsic muscles are small with short moment arms and primarily provide foot stability (74). The larger extrinsic muscles can generate more force, and with larger moment arms produce joint rotations. ...
Minimal footwear has existed for tens of thousands of years and was originally designed to protect the sole of the foot. Over the past 50 years, most footwear has become increasingly more cushioned and supportive. Here we review evidence that minimal shoes are a better match to our feet which may result in a lower risk of musculoskeletal injury.
... Additionally, these clinicians believed that injuries were occurring from some runners experiencing too much impact, while others too much foot pronation. 15 This collective input led to the development of an elevated cushioned heel. In addition to the neutral shoe, Nike, along with other shoe companies, also produced cushioned and motion control models of their running shoes to mitigate excessive impacts and pronation. ...
... But the very features that were developed to assist the runner may have very well resulted in setting them up for increased risk of injury. 15 Chronic support of any muscle will lead to disuse and weakness. In fact, in a recent study, 12 weeks of foot orthotic use resulted in a 10%e17% reduction in the foot intrinsic muscle size. ...
... Finally, shoes with less cushioning can effectively increase intrinsic foot muscle strength. 15 Structural stability or motion control components. Some commercially available shoes contain structures that modify the foot motion to help improve foot posture, provide stability, and prevent pronation during loading. ...
... Simply walking in minimal shoes without support increases foot muscle size and strength. In a prospective study, Ridge et al. [82] assessed the baseline size (using ultrasound) of four intrinsic muscles (abductor hallicus, flexor hallicus brevis, flexor digitorum brevis, and quadratus plantae) and three extrinsic muscles (tibialis posterior, tibialis anterior, and flexor digitorum longus). Baseline strength of arch doming and toe flexion was also measured. ...
... A recent cross-sectional study compared the foot strength and arch stiffness of individuals habituated to walking in minimal shoes to those habituated to conventional shoes [83]. As with Ridge et al. [82], these authors noted larger abductor hallucis and abductor digiti minimi muscles (but not flexor digitorum brevis) in the minimally shod group. Additionally, arch height and arch stiffness were greater in this group. ...
... Excessive deformation of the arch is facilitated by weakness of the intrinsic foot muscles [2][3][4]6,7]. Modern footwear use is associated with weaker intrinsic foot muscles [7,8] a greater prevalence of flat feet [9] and changes to the shape of the foot that are not seen in habitually barefoot or minimally shod populations [7,10,11]. ...
... This is evident from habitually barefoot populations having a lower prevalence of flat foot and larger abductor hallucis and abductor digit minimi muscles [7,9,42,43]. Furthermore, shod populations who demonstrate the reverse in terms of arch integrity and foot muscle morphology, can develop functional foot characteristics more in likeness to habitually barefoot populations after a period of barefoot or minimally shod walking and running [8,44]. It may be these adaptations that have contributed to the sustained reduction in pain in the runners in this study at 6 and 12-weeks. ...
Background:
Foot characteristics and running biomechanics in shod populations are associated with the aetiology of plantar fasciitis, the most common musculoskeletal disease of the foot. Previous Case reports have demonstrated improvements in the symptoms of plantar fasciitis after a period of barefoot running on grass.
Methods:
Recreational runners with symptomatic plantar fasciitis were prospectively enrolled into a 6-week grass based barefoot running programme. Duration of symptoms, previous management and current pain scores (NRS, VAS) were recorded at entry. Daily pain scores were recorded during the 6-week period and 12 weeks from entry to the programme.
Results:
In total, 20 of 28 patients (71.4%) enrolled were included in the analysis. Relative to the entry point, pain at 6-weeks was lower (2.5 ± 1.4 vs. 3.9 ± 1.4, p < 0.001) and pain at the 12-week point was lower (1.5 (1.8), p = 0.002). 19 out of 20 patients had improved at week-6 (mean ± SD % change in pain score, -38.8 ± 21.5%) and at week-12 (median (IQR) % change in pain score, -58.3 (34.8) %).
Conclusion:
Barefoot running on grass improved pain associated with plantar fasciitis at the 6-week and 12-week follow up points. This type of barefoot running has the ability to improve symptoms whilst allowing patients to continue running, the intervention may also address some impairments of the foot associated with plantar fasciitis.
... Interventions to augment foot muscle strength could enhance foot function and thus help prevent injuries to the foot and ankle [2,4]. Previous studies showed that daily foot core exercise (FCE) could improve the intrinsic foot muscle strength and thus help enhance jumping and postural control performance [5][6][7]. Meanwhile, in regulating foot function, the mechanoreceptors within the soles of the foot perceive the sensory information from the environment, and such afferent information is delivered to the supraspinal regions via peripheral nerves and spinal cord and activates a distributed cortical network within the brain [8]. ...
... The FCE in this study consisted of foot doming, towel curls, toe spread and squeeze, and balance board training, with a goal to strengthen intrinsic and extrinsic foot muscles and the functionalities of the foot and ankle [7]. ...
Objective
This study aimed to examine the effects of combining transcranial direct current stimulation (tDCS) and foot core exercise (FCE) on the sensorimotor function of the foot (i.e., toe flexor strength and passive ankle kinesthesia) and static balance.
Methods
In this double-blinded and randomized study, 30 participants were randomly assigned into two groups: tDCS combined with FCE and sham combined with FCE (i.e., control group). The participants received 2 mA stimulation for 20 min concurrently with FCE over 4 weeks (i.e., three sessions per week). After the first two groups completed the intervention, a reference group (FCE-only group) was included to further explore the placebo effects of sham by comparing it with the control group. Foot muscle strength, passive ankle kinesthesia, and static balance were assessed at baseline and after the intervention.
Results
Compared with the control group and baseline, tDCS combined with FCE could increase toe flexor strength ( p < 0.001) and decrease the passive kinesthesia threshold of ankle eversion ( p = 0.002). No significant differences in static balance were observed between tDCS + FCE and control groups. The linear regression models showed an association towards significance between the percent changes in metatarsophalangeal joint flexor strength and the anteroposterior average sway velocity of the center of gravity in one-leg standing with eyes closed following tDCS + FCE ( r 2 = 0.286; p = 0.057). The exploratory analysis also showed that compared with FCE alone, the sham stimulation did not induce any placebo effects during FCE.
Conclusion
Participating in 4 weeks of intervention using tDCS in combination with FCE effectively enhances toe flexor strength and foot–ankle sensory function.
... During daily weight-bearing activities (e.g., walking), the foot functions by performing force attenuation with loading, transmitting force during propulsion, providing afferent information to accommodate uneven terrain, and maintaining postural control (Kelly et al., 2014;Fraser and Hertel, 2019). The diminished sensorimotor function of the foot and ankle has been linked to poor functional performance and associated with loadingrelated injuries (Ridge et al., 2019;Kakouris et al., 2021). For example, weakness of the intrinsic foot muscles suggested that inefficient active support of the arch may contribute to injuries, such as plantar fasciitis (Wearing et al., 2006;van Poppel et al., 2021). ...
... For the FCE group, the training sessions consisted of short foot exercise, towel curls, toe spread and squeeze, and balance board training ( Figure 2), with the goal to strengthen the intrinsic and extrinsic foot muscles and the functionalities of the foot and ankle ( Table 2) (Ridge et al., 2019). All participants were verbally instructed, provided with a demonstration, and guided through a single practice trial. ...
Objective: This study aimed to examine the effects of 4 weeks of high-definition transcranial direct current stimulation (HD-tDCS) and foot core exercise (FCE) on foot sensorimotor function (i.e., toe flexor strength and passive ankle kinesthesia) and postural control.
Methods: In total, 36 participants were randomly assigned into three groups as follows: HD-tDCS, FCE, and the control group. A total of 12 training sessions were performed over 4 weeks (i.e., three sessions per week) in the laboratory. The HD-tDCS group received 20-min HD-tDCS with a current density of 2 mA, and the FCE group completed short foot exercise, towel curls, toe spread and squeeze, and balance board training. Participants in the control group just maintained the activities what they usually did and did not receive any interventions. Foot muscle strength, passive ankle kinesthesia, and postural control were assessed at baseline and post-intervention.
Results: HD-tDCS induced a greater decrease in the percentage changes in the passive kinesthesia thresholds of ankle inversion ( p < 0.001) and eversion ( p = 0.013) than the control group. Compared with the control group, a significant increase in the percentage change in the metatarsophalangeal joint flexor strength was found in the HD-tDCS group ( p = 0.008) and the FCE group ( p = 0.027), and a significant increase in the percentage change in toe flexor strength was observed in the FCE group ( p = 0.015). Moreover, FCE induced a greater reduction in the percent changes in the medial–lateral average center of gravity sway velocity in one-leg standing with eyes open ( p = 0.033) and the anteroposterior average center of gravity sway velocity in one-leg standing with eyes closed ( p < 0.001) than control.
Conclusion: This study demonstrated that 4 weeks of HD-tDCS and FCE induced distinct benefits on foot sensorimotor function and the standing postural control performance in healthy young adults. HD-tDCS could improve the metatarsophalangeal joint flexor strength and the passive kinesthesia thresholds of ankle inversion and eversion. Meanwhile, FCE could also enhance foot muscle strength and enhance postural control performance in one-leg standing.
... Since this systematic review, numerous studies emerged in which the effect of interventions aimed to improve PIFM strength was investigated. These studies demonstrated a beneficial effect pertaining to PIFM strength and hypertrophy [37][38][39][40][41]. However, it is not clear to what extent this reflects improved dynamic function. ...
... The latter is expected to interfere with exercise performance and is negatively associated with adherence [43]; studying the effect of noninvasive interventions anticipated to improve PIFM strength. As the focus is on strength, as opposed to neuromuscular adaptations, interventions had to last at least 4 weeks [38,44]. These interventions include, for example but were not restricted to, 1) muscle strengthening programs composed of 'short foot' or 'foot doming' exercises or exercises requiring toe flexion muscle force (e.g., toe plantar flexion, towel curl exercise, marble pick up, heel raises) or toe ab−/adduction muscle force (e.g., toe spread out), 2) a transition from conventional to minimal shoe or barefoot condition; reporting outcome measures, at least assessed at baseline and directly post intervention, that are related to the locomotor system's function on balance control and propulsion. ...
Background
The plantar intrinsic foot muscles (PIFMs) have a role in dynamic functions, such as balance and propulsion, which are vital to walking. These muscles atrophy in older adults and therefore this population, which is at high risk to falling, may benefit from strengthening these muscles in order to improve or retain their gait performance. Therefore, the aim was to provide insight in the evidence for the effect of interventions anticipated to improve PIFM strength on dynamic balance control and foot function during gait in adults.
Methods
A systematic literature search was performed in five electronic databases. The eligibility of peer-reviewed papers, published between January 1, 2010 and July 8, 2020, reporting controlled trials and pre-post interventional studies was assessed by two reviewers independently. Results from moderate- and high-quality studies were extracted for data synthesis by summarizing the standardized mean differences (SMD). The GRADE approach was used to assess the certainty of evidence.
Results
Screening of 9199 records resulted in the inclusion of 11 articles of which five were included for data synthesis. Included studies were mainly performed in younger populations. Low-certainty evidence revealed the beneficial effect of PIFM strengthening exercises on vertical ground reaction force (SMD: − 0.31-0.37). Very low-certainty evidence showed that PIFM strength training improved the performance on dynamic balance testing (SMD: 0.41–1.43). There was no evidence for the effect of PIFM strengthening exercises on medial longitudinal foot arch kinematics.
Conclusions
This review revealed at best low-certainty evidence that PIFM strengthening exercises improve foot function during gait and very low-certainty evidence for its favorable effect on dynamic balance control. There is a need for high-quality studies that aim to investigate the effect of functional PIFM strengthening exercises in large samples of older adults. The outcome measures should be related to both fall risk and the role of the PIFMs such as propulsive forces and balance during locomotion in addition to PIFM strength measures.
... Quatro estudos analisaram o gasto energético. Dois deles (FULLER et al., 2017;RIDGE et al., 2019), em suas análises, chegaram à conclusão de que os tênis minimalistas reduziram o consumo de energia, enquanto outros dois (LINDLEIN et al., 2018;WARNE et al., 2017), verificaram que os minimalistas aumentaram o consumo de energia. Os artigos incluídos nesta revisão apontam para um aumento no risco de lesão nos tênis minimalistas em relação aos tradicionais. ...
... Quando se extrapola essa informação para os treinos de corrida, podemos perceber que, para uma mesma distância, o corredor em uso de tênis minimalista tenderá a aumentar a cadência. É de se esperar que o aumento da frequência de movimentos dos membros inferiores repercuta em aumento do número de contrações musculares tanto concêntricas na fase de propulsão quanto excêntricas na aterrisagem de tal maneira que tenderia a aumentar o gasto energético nos corredores com tênis minimalista, entretanto essa hipótese só foi encontrada nos estudos de (LINDLEIN et al., 2018;RIDGE et al., 2019). Já nos estudos de (FULLER et al., 2019;WARNE et al., 2017), os tênis minimalistas produziram um efeito contrário: reduziram o gasto energético mesmo que discretamente. ...
Introdução: a altura do salto (drop) do tênis de corrida é um dos principais temas que vem recebendo atenção de corredores e da indústria ligada à corrida. De um lado, temos tênis tradicionais com mais estrutura e foco no amortecimento e, do outro, os tênis minimalistas mais leves e flexíveis, que procuram deixar a corrida mais próxima dos pés descalços. A busca por uma corrida mais natural e com mínima influência do tênis tem disparado interesse cada vez mais frequente nos minimalistas. Entretanto, essa mudança de paradigma tende a alterar o padrão de corrida e influenciar no surgimento de lesão. Dessa maneira, o objetivo deste estudo é verificar o efeito do drop dos tênis de corrida na cinemática e na incidência de lesão. Metodologia: tendo como base o modelo PRISMA, foi realizada uma revisão sistemática com metanálise com busca de ensaios clínicos nos principais bancos de dados: Pubmed, EMBASE, CIHNAL e Cochrane. Resultados: 117 artigos foram encontrados, e 16 atenderam aos critérios de inclusão e foram incluídos nesta revisão. Todos os artigos foram submetidos à avaliação da qualidade metodológica pela escala PEDro. O uso dos tênis minimalistas aumenta a incidência de lesão em corredores (RR 2,59, 95% CI 1.93 - 3.27), reduz o comprimento do passo e aumenta a cadência. Conclusão: o uso do tênis minimalista, parece reduzir a capacidade dos tênis em mitigar as cargas, influencia no aumento da cadência e, aumenta a incidência de lesão em corredores.
... Anecdotal evidence from experienced coaches suggests that barefoot running on softer surfaces such as grass has been used as a training regimen for the strengthening of extrinsic and intrinsic foot muscles by track and field coaches already decades ago (1). More recently, it was shown that running in minimal footwear induced increases in strength and cross sectional areas of extrinsic and intrinsic foot muscles compared with training in conventional footwear (2,5,10,11,23,37). Overall, it seems that the use of minimal footwear or barefoot running can improve strength capacities at the foot and the ankle. ...
... Greater stress is also placed on the triceps surae that functions to transmit force through the Achilles tendon to the calcaneus. Therefore, it is possible that running barefoot regularly with sufficient rest periods can lead to positive adaptations of these structures, which has already been shown for running in minimal footwear (2,5,23,37). However, a sudden increase in stress can also lead to overuse of these structures specifically if rest periods are too short or training intensity and/or volume is too high. ...
Willwacher, S, Fischer, KM, Rohr, E, Trudeau, MB, Hamill, J, and Brüggemann, G-P. Surface stiffness and footwear affect the loading stimulus for lower extremity muscles when running. J Strength Cond Res XX(X): 000-000, 2020-Running in minimal footwear or barefoot can improve foot muscle strength. Muscles spanning the foot and ankle joints have the potential to improve performance and to reduce overuse injury risk. Surface stiffness or footwear use could modify the intensity of training stimuli acting on lower extremity joints during running. The purpose of this study was to systematically investigate external ankle, knee, and hip joint moments during shod and barefoot running while considering the stiffness of the running surface. Two footwear conditions (barefoot and neutral running shoe) and 4 surface conditions (Tartan, Tartan + Ethylene Vinyl Acetate [EVA] foam, Tartan + artificial turf, Tartan + EVA foam + artificial turf) were tested at 3.5 m·s. Repeated measures analysis of variance revealed that barefoot running in general and running barefoot on harder surfaces increased and decreased ankle (between +5 and +26%) and knee (between 0 and -11%) joint moments, respectively. Averaged over all surfaces, running barefoot was characterized by a 6.8° more plantarflexed foot strike pattern compared with running shod. Foot strike patterns were more plantarflexed on harder surfaces; the effects, however, were less than 3°. Most surface effects were stronger in barefoot compared with shod running. Surface stiffness may be used to modulate the loading intensity of lower extremity muscles (in particular extrinsic and intrinsic foot muscles) during running. These results need to be considered when coaches advise barefoot running as a method to improve the strength of extrinsic and intrinsic foot muscles or when trying to reduce knee joint loading.
... Foot muscle strengthening has been emphasised to protect runners from overuse injuries for several years. Most often barefoot or minimal footwear exercise is proposed due to the proven strength improvements when running in minimal footwear [34][35][36][37][38][39][40] or more general with a mid-/forefoot running style [41]. However, future studies need to directly address whether strengthening ankle invertors or hip abductors affects the biomechanical fatigue response during prolonged running. ...
... Nonetheless, specific foot muscle strengthening regimes can provide an additional training stimulus to improve the strength capacities of extrinsic and intrinsic foot muscles [36,42]. However, it is important to consider that an increased capacity to withstand the external loads might not guarantee reductions of fatigue-related changes in joint kinematics [43]. ...
Background:
Fatigue is an essential component of distance running. Still, little is known about the effects of running induced fatigue on three-dimensional lower extremity joint movement, in particular in the frontal and transverse planes of motion.
Research question:
How are non-sagittal plane lower extremity joint kinematics of runners altered during a 10 km treadmill run with near-maximum effort?
Methods:
In a cross-sectional study design, we captured three-dimensional kinematics and kinetics at regular intervals throughout a 10 km treadmill run in 24 male participants (subdivided into a competitive and recreational runner group) at a speed corresponding to 105 % of their season-best time. We calculated average and peak joint angles at the hip, knee and ankle during the stance phase.
Results:
We observed peak deviations of 3.5°, 3° and 5° for the hip (more adduction), knee (more abduction) and ankle (more eversion) in the frontal plane when comparing the final (10 km) with the first (0 km) measurement. At the end of the run peak knee internal rotation angles increased significantly (up to 3° difference). Running with a more abducted knee joint and with a higher demand for hip abductor muscles in the unfatigued state was related to greater fatigue-induced changes of joint kinematics at the knee and hip.
Significance:
The fatigue related change of non-sagittal joint kinematics needs to be considered when addressing risk factors for running-related injuries, when designing shoe interventions as well as strengthening and gait retraining protocols for runners. We speculate that strengthening ankle invertors and hip abductors and monitoring the dynamic leg axis during running appear to be promising in preventing fatigue induced alterations of non-sagittal joint kinematics.
... The assessment of foot muscle strength is addressed in the literature with magnetic resonance imaging (MRI) or ultrasound imaging (USI) (Soysa et al., 2012;Gooding et al., 2016;Ridge et al., 2018) in order to quantify muscle thickness or cross sectional area, but these modalities are expensive and not applicable on the field by coaches or athletic trainers. Numerous other affordable measurement methods are available and come with an interesting level of validity and reliability. ...
... The literature on the effects of running on foot muscular adaptations is relatively scarce and somewhat contradictory. Nevertheless, it does suggest that running could improve the cross-sectional area and the volume of foot muscles, and that this may be modulated by running mileage and experience (Miller et al., 2014;Johnson et al., 2015;Chen et al., 2016;Ridge et al., 2018). Based on the limited evidence available, there seems to be a positive effect of running on intrinsic muscle strength and size (Garofolini and Taylor, 2019). ...
The foot is a complex system with multiple degrees of freedom that play an essential role in running or sprinting. The intrinsic foot muscles (IFM) are the main local stabilizers of the foot and are part of the active and neural subsystems that constitute the foot core. These muscles lengthen eccentrically during the stance phase of running before shortening at the propulsion phase, as the arch recoils in parallel to the plantar fascia. They play a key role in supporting the medial longitudinal arch, providing flexibility, stability and shock absorption to the foot, whilst partially controlling pronation. Much of the foot rigidity in late stance has been attributed to the windlass mechanism – the dorsiflexion of the toes building tension up in the plantar aponeurosis and stiffening the foot. In addition, recent studies have shown that the IFM provide a necessary active contribution in late stance, in order to develop sufficient impedance in the metatarsal-phalangeal joints. This in turn facilitates the propulsive forces at push-off. These factors support the critical role of the foot in providing rigidity and an efficient lever at push-off. During running or sprinting, athletes need to generate and maintain the highest (linear) running velocity during a single effort in a sprinting lane. Acceleration and sprinting performance requires forces to be transmitted efficiently to the ground. It may be of particular interest to strengthen foot muscles to maintain and improve an optimal capacity to generate and absorb these forces. The current evidence supports multiple exercises to achieve higher strength in the foot, such as the “short foot exercise,” doming, toes curl, towing exercises or the more dynamic hopping exercises, or even barefoot running. Their real impact on foot muscle strength remains unclear and data related to its assessment remains scarce, despite a recognized need for this, especially before and after a strengthening intervention. It would be optimal to be able to assess it. In this article, we aim to provide the track and field community with an updated review on the current modalities available for foot strength assessment and training. We present recommendations for the incorporation of foot muscles training for performance and injury prevention in track and field.
... Habitually barefoot populations have wider forefoot than those with a conventional shoe (Ashizawa et al., 1997). In addition, it is known that wearing minimalist shoes, enabling to imitate barefoot running or walking (Squadrone & Gallozzi, 2009), increases plantar pressure in the forefoot region (Bergstra et al., 2015) and induces hypertrophy of plantar intrinsic foot muscles to counter the load against the foot (Ridge et al., 2019). Thus, the observed correlations between forefoot width and circumferential parameters and the MV of plantar intrinsic foot muscles, especially those that run along the longitudinal direction of the foot and specialized in toe flexion (FHB, FDB, QP), may reflect the structural development of human feet to adapt to the loads produced by locomotion. ...
Human plantar intrinsic foot muscles consist of 10 muscles that originate and insert within the sole of the foot. It is known that the anatomical cross-sectional area (ACSA) and muscle thickness of two plantar intrinsic foot muscles, the flexor hallucis brevis (FHB) and abductor hallucis (ABH), associate with morphological parameters of the foot, such as total and truncated foot length and navicular height. However, it is unclear how the size for each of the plantar intrinsic foot muscles associates with various morphological profiles of the foot. This study aimed to elucidate this subject. By using magnetic resonance imaging (MRI), serial images of the right foot were obtained in 13 young adult men without foot deformities. From the obtained MR images, ACSA for each of the individual plantar intrinsic foot muscles was analyzed along the foot length, and then its muscle volume (MV) was calculated. The analyzed muscles were the abductor digiti minimi (ABDM), ABH, adductor hallucis oblique head (ADDH-OH), adductor hallucis transverse head (ADDH-TH), flexor digitorum brevis (FDB), FHB, and quadratus plantae (QP). Furthermore, MV of the whole plantar intrinsic foot muscle (WHOLE) was defined as the total MVs of all the analyzed muscles. As morphological parameters, total foot length, truncated foot length, forefoot width, ball circumference, instep circumference, navicular height, great toe eversion angle, and little toe inversion angle were measured using a laser three-dimensional foot scanner in standing and sitting conditions. In addition, navicular drop (ND) and normalized truncated navicular height (NTNH) were also calculated as medial longitudinal arch (MLA) height indices. The MV of WHOLE was significantly associated with the forefoot width, ball circumference, and instep circumference (r = 0.647-0.711, p = 0.006-0.013). Positive correlations were found between the forefoot width and MV of FHB, FDB, and QP (r = 0.564-0.653, p = 0.015-0.045), between the ball circumference and MV of QP (r = 0.559, p = 0.047), between the instep circumference and MV of FHB (r = 0.609, p = 0.027), and between the little toe inversion angle and MV of QP (r = 0.570, p = 0.042). The MVs of ABH, ABDM, and ADDH-OH were not significantly correlated with any morphological parameters of the foot. Similarly, no significant correlations were found between MV of each muscle and either of the MLA height indices (ND and NTNH). Thus, the current results indicate that forefoot width and circumferential parameters (instep and ball circumference), not MLA height, associate with the size of the whole plantar intrinsic foot muscles, especially those specialized in toe flexion (FHB, FDB, and QP).
... The convenience of changing footwear rather than performing specific exercises may result in greater compliance. This line of reasoning may also explain the gain in functional improvement of the feet during gait in women with foot disease, as is the case with PCS [54]. ...
Backround
Calcaneal spurs are described as bony outgrowths arising on medial calcaneal, where inappropriate footwear can promote disease progression.
Objective
Investigate the effectiveness of mechanical treatment with customized insole and minimalist flexible footwear during gait training program in women with calcaneal spur.
Methods
Design: A single-blinded, randomized and controlled trial. Setting: Biomechanics laboratory. Participants: Forty-three women, 29 with calcaneal spur and 14 control.
Intervention
Gait training program with use of the minimalist flexible footwear (MFG n = 15, age: 48.9 ± 9.4, height: 1.61 ± 0.1, BMI: 32.1 ± 7.0) and customized insole on footwear (COIG n = 14, age: 50.3 ± 5.8, height: 1.62 ± 0.1, BMI: 32.2 ± 4.3) and control (CG n = 14, age: 47.8 ± 8.6, height: 1.63 ± 0.1, BMI: 27.5 ± 4.5), followed of the evaluations: baseline (T0) and after three (T3) and six (T6) months. Duration of the intervention was of the six months consecutive for at least 42 h per week (six hours a day, seven days a week). Outcome primary were calcaneus pain (visual analogue scale), Foot Function Index (FFI), Foot Health Status Questionnaire (FHSQ-Br) and 6-min walk test (6MWT). Secondary was plantar pressure distribution by a pressure platform system during gait and static index foot posture (FPI). Statistical analysis: analysis of variance for repeated measure and between groups were used to detect treatment-time interactions (α = 5%). Effect size with D Cohen’s also was used between T0 and after six (T6) months of intervention.
Results
The MFG and COIG were effective at reducing pain after six months (MFG: 2.5–4.5 CI, p = 0.001; COIG: 1.5–3.5 CI, p = 0.011). The FFI and FHSQ-Br showed improvements with MFG and COIG after T6 (MFG: 13.7–15.4 CI, p = 0.010; COIG: 11.3–15.0 CI, p = 0.001). The 6MWT increased with MFG (589.3–622.7 CI) and COIG (401.3–644.7 CI) and foot pronation was decreased after T3 and T6 MFG (FPI Right: 4.2–5.4 CI; Left: 3.6–5.4 CI) COIG (FPI Right: 3.4–6.8 CI; Left: 3.3–5.7 CI). The contact area reduced on forefoot and rearfoot with MFG and GOIG and midfoot and rearfoot with MFG. Maximum force was reduced on foot with MFG after T3 and T6. The peak pressure was reduced on the forefoot with MFG and COIG and on midfoot and rearfoot with MFG.
Conclusions
The mechanical treatment with customized insole and minimalist flexible footwear during gait training program during six months in women with calcaneal spur reduced the calcaneus pain, increased function and health feet and reduced plantar load on the rearfoot, midfoot and forefoot. However, the footwear alone was more effective than when combined customized insole, given the greater efficacy on clinical and biomechanical aspects.
Trial registration
ClinicalTrials.gov NCT03040557 (date of first registration: 02/02/2017).
... Weak intrinsic foot muscles have been implicated in various foot disorders such as flat feet, hallux valgus, claw toe and hammertoe in children [79,80]. In adults, evidence suggests that being barefoot or wearing minimal shoes free of arch support improves intrinsic and extrinsic foot muscle strength [81][82][83][84]. To date, no research studies have tested the hypothesis that spending time barefoot or in minimal shoes can strengthen the intrinsic foot muscles in children; however, many have speculated about the effect that footwear has on foot strength [50,80,83,[85][86][87]. ...
The theory that footwear may change foot shape dates back 100 years. Since this period, research has revealed the anatomical and functional consequences that footwear can cause to the foot. Children’s feet remain malleable as they undergo developmental changes until adolescence, which is why childhood is arguably a crucial period to understand how footwear can affect natural foot development. This review explored the development of the foot in children and adolescents and the methods used to measure the different foot structures; it comments on the key issues with some of these methods and gives direction for future research. Various internal and external factors can affect foot development; the main factors are age, gender, ethnicity, body mass index (BMI) and footwear habits. Research on how footwear can affect foot development has increased over the years and the final section of this review aimed to unpick the findings. Studies investigating the influence of footwear habits on foot length and width have established inconsistent findings. Many of the studies in the review did not control for internal and external factors that can affect foot development. There was also a limited number of studies that investigated hallux valgus angle and muscle strength differences in those with different footwear habits. Moreover, multiple studies in the final section of this review did not successfully examine the footwear habits of the participants and instead used observations or self-assessments, which is a major limitation. Future research should examine footwear behaviors and other confounding factors when investigating the development of the foot in children and adolescents. Moreover, researchers should critically evaluate the methods used to quantify the different structures of the foot to ensure valid and reliable parameters are being used.
... In accordance with other studies (Fong Yan et al., 2013;Franklin et al., 2015;Hollander et al., 2019;Ogston, 2019;Ridge et al., 2019) we anticipate a need for investigating the long-term effects of different footwear and especially of non-cushioned minimalist shoes on the musculoskeletal system during walking (Davis et al., 2021). Most studies (Bonacci et al., 2013;Hollander et al., 2015;2019;Ogston, 2019;Squadrone & Gallozzi, 2009) focus on running instead of walking. ...
Minimalist shoes are proposed to promote walking gait patterns more similar to natural bare-
foot gait. While there is already considerable research evaluating the effects of minimalist shoes
on running biomechanics, little has been reported about the effects of minimalist shoes on kine-
matic and kinetic parameters during normal gait. Therefore, the purpose of this study was to
compare biomechanical gait parameters between walking in non-cushioned minimalist shoes, in
conventional cushioned shoes and barefoot. Kinematic (cadence, step length, foot progression
angle, length of CoP) and kinetic (vGRF) parameters of 32 healthy adults were collected at pre-
ferred walking speed on an instrumented treadmill. ANOVA or Friedman- Tests were applied for
between condition comparisons. In case of significant (p < 0.05) main effects, post-hoc analyses
were implemented for pairwise comparisons. Significant main effects of footwear conditions
were found for all parameters (p < .001). Post-hoc analyses revealed that increased cushioning
properties of the applied footwear are associated with increased step lengths, lengths of CoP
trajectory and foot progression angle as well as a reduced cadence. Additionally, decreased
cushioning resulted in increased vGRF, especially of the forefoot and rearfoot. Results indicate
that footwear significantly affects biomechanical gait parameters in a group of healthy adults.
The findings have implications on the use of footwear during walking gait, with special
emphasis on the cushioning properties of the different conditions.
... Magnetic resonance imaging (MRI) and ultrasound (US) imaging are both used to indirectly measure intrinsic foot muscle size and estimate muscle strength [24][25][26][27]. MRI is considered the criterion standard due to its high resolution and multi-planar view [10]. ...
Purpose
Intrinsic foot muscles maintain foot structural integrity and contribute to functional movement, posture and balance. Thus, assessing intrinsic foot muscle size and strength are important. Magnetic resonance imaging (MRI) has been shown to accurately image the individual muscles but is costly and time consuming. Ultrasound (US) imaging may provide an alternative that is less costly and more readily available. The purpose of this study was to investigate the validity and intratester reliability of US imaging in measuring intrinsic foot muscle size in comparison to MRI.
Methods
US and MRI were employed to measure the intrinsic foot muscle size involving 35 participants (females = 13; males = 22). The scanned intrinsic foot muscles included the flexor hallucis brevis (FHB), abductor hallucis (ABDH), flexor digitorum brevis (FDB), quadratus plantae (QP) and abductor digiti minimi (ADM). Pearson product correlation (r), intraclass correlation coefficients (ICC), standard error of the measurement (SEm) and minimal detectable difference (MDD) were calculated.
Results
High correlations were detected between the US and MRI cross-sectional area (CSA) measurements ( r = .971 to 0.995). Test reliability was excellent for both MRI and US (ICC = 0.994 to 0.999). Limits of agreement between MRI and US measurements from ranged from 5.7 to 12.2% of muscle size. SEm values for US ranged from 0.026 to 0.044 cm2, while the SEm for MRI ranged from 0.018 to 0.023 cm2. MDD values for US ranged from 0.073 to 0.122 cm2, while MRI ranged from 0.045 to 0.064 cm2.
Conclusions
US appears to be a valid and reliable alternative to MRI when measuring intrinsic foot muscle CSA. While US is less costly and more readily available, the MRI results were shown to be slightly more precise.
... Intrinsic foot muscle strength To measure the strength of supporting the foot arch, the intrinsic foot muscle strength will be collected during a special functional movement known as 'doming'. The measurement of intrinsic foot muscle strength will be conducted on custom-built apparatuses with a dynamometer, which has been reported in previous studies (ICC = 0.949, SEM = 0.883 kg) [36,37]. The participants will be instructed to perform the doming movement by activating muscles to pull the metatarsal heads towards the heel (also known as the short-foot exercise). ...
Background
Falls are one of the most common accidents in older adults, often leading to injury, disability and quality-of-life declines. Foot core function contributes to postural stability in most static postures and dynamic activities. As efficient foot core training, the intrinsic-foot-muscle exercise has been proposed to improve postural control. However, the effects of the exercise on postural stability in the elderly remain unclear. Therefore, this study attempts to investigate the effect of 12-week intrinsic-foot-muscle exercise on postural stability in older adults with fall risk.
Methods
We will conduct a prospective, single-blind randomised controlled trail on 120 older adults with fall risk. Participants will be randomly assigned to an intrinsic-foot-muscle exercise combining the lower extremity resistance training group (IFM group), an extrinsic-foot-muscle exercise combining the lower extremity resistance training group (EFM group) and a control group. The control group will perform lower extremity resistance training. The IFM and EFM groups will be given additional short-foot exercise or towel-curl exercise training, respectively. After the intervention, participants will be followed up for another 12 weeks with no active intervention. The outcome measures will include the postural stability measurements, self-reported postural stability, number of falls, intrinsic-foot-muscle strength and foot arch function. Furthermore, adverse events will be recorded and analysed. If any participant withdraws from the trial, an intention-to-treat analysis will be performed.
Discussion
The trial is designed to investigate the efficacy of a 12-week intrinsic foot muscle training combined with the lower extremity resistance training on postural stability outcomes in elderly people with fall risk. The trial will also examine the comprehensive outcomes of postural stability during static standing and dynamic movements. The function of intrinsic foot muscle to support the arch will also be evaluated. Important features of this trial mainly include intervention setting, outcome measure selection and study duration. The results of this study will determine the effectiveness and provide scientific evidence to establish comprehensive fall prevention intervention.
Trial registration
Chinese Clinical Trial Registry ChiCTR2000033623. Registered on 7 June 2020. http://www.chictr.org.cn/showproj.aspx?proj=54741
... This finding may impact the planning of interventions for improving lower limb mechanics and treating some musculoskeletal conditions. Strengthening exercises for the foot intrinsic muscles have been advocated for pronated and low-arched feet (Jung et al., 2011;Ridge et al., 2019). However, intrinsic muscle exercises should also focus on producing soft tissue adaptations to increase the foot core's passive stiffness (Jung et al., 2011;Taddei et al., 2020). ...
The midfoot joint complex (MFJC) is related to the mechanics and efficiency of the walking propulsive phase and low midfoot passive stiffness may require compensatory foot and ankle joint moments to avoid excessive pronation and inefficient propulsion. This study aimed to investigate the kinematics and kinetics of the MFJC and ankle during the propulsive phase of walking in subjects with larger and smaller midfoot passive stiffness. MFJC passive stiffness of 20 healthy adult participants, and the kinematics and kinetics of the MFJC (forefoot-rearfoot) and ankle (rearfoot-shank) during the stance phase of walking were measured. The participants were divided equally into two groups according to the MFJC passive stiffness. Ranges of motion (ROM) and mean joint moments were computed for the late stance. Independent t-tests (α=0.05) revealed that subjects with lower midfoot passive stiffness showed an increased MFJC sagittal ROM (flattened longitudinal arch) (p=0.002), increased ankle frontal ROM (more everted positions) (p=0.002), increased MFJC frontal ROM (more inverted positions) (p=0.019), as well as a tendency for larger ankle sagittal ROM (p=0.056). They also showed increased MFJC (p=0.021) and ankle (p=0.018) moments in the sagittal plane, increased MFJC moment in the frontal plane (p=0.047) and a tendency for a predominant ankle moment in the frontal (p=0.058). Foot and ankle joint moments are possible strategies to reduce pronation and improve propulsion, but not sufficient to prevent the altered kinematics related to low midfoot stiffness. Therefore, midfoot passive stiffness is critical for foot and ankle kinematics and kinetics during walking propulsive phase and is a potential target of interventions.
... However, the opposite approach can be used, and indeed it has been shown that athletes training in 'minimal' footwear gain foot muscle strength compared to those using conventional trainers (Goldmann et al., 2013;Miller et al., 2014). Using minimal footwear during daily life has been shown to both increase foot strength (Ridge et al., 2019), balance (Cudejko et al., 2020, and gait performance (Petersen et al., 2020). ...
Humans evolved as barefoot walkers, and only started to use footwear recently in evolutionary history. It can be questioned what the effect is of footwear on gait. This effect has previously been studied for a range of conventional and athletic footwear, but this study focuses on indigenous footwear which does not have the features commonly associated with conventional footwear, such as a raised heel, a relatively narrow toe box, arch support, and a firm heel cup. We will assess whether such footwear can be considered functionally ‘minimal’ and simulate barefoot walking, by analysing spatial and temporal aspects of plantar pressure distribution. We first compare the 2 D spatial distribution of plantar pressure, using 2 D Statistical Parametric Mapping, between four populations walking barefoot and with indigenous or commercial minimal shoes. We compared Indians wearing sandal-like footwear (‘Kolhapuri’), Scandinavians wearing boot-type footwear (‘Nuvttohat’), Namibian San wearing sandal-like footwear (‘N!ang n|osi’) and Western Europeans wearing a commercial minimal shoe, and conventional Western footwear. Within each population, indigenous and commercial barefoot footwear data were compared to barefoot walking. No statistically significant differences were found within-population between all footwear conditions and barefoot walking. Second, we question whether there were 1 D temporal differences in centre of pressure movements between three footwear conditions (barefoot, commercial minimal, conventional Western) within one, Western, population. Using 1 D Statistical Parametric Mapping, differences between these three conditions are shown, with barefoot walking keeping a more proximal CoP position than both footwear conditions during most of push-off phase. Based on plantar pressure recordings, we conclude that all indigenous and commercial minimal shoes can functionally be considered ‘minimal footwear’, but with some differences to barefoot walking.
... Indeed, intervention studies have shown consistent changes across individuals after walking or running barefoot or in minimal footwear for several weeks. These changes include increased strength and size of foot muscles, increased foot and leg stiffness, and greater use of the spring-like function of the medial longitudinal arch (Brüggemann et al., 2005;Chen et al., 2016;De Wit et al., 2000;Johnson et al., 2015;Miller et al., 2014;Perl et al., 2012;Ridge et al., 2018). ...
One of the purposes of footwear is to assist locomotion, but some footwear types seem to restrict natural foot motion, which may affect the contribution of ankle plantar flexor muscles to propulsion. This study examined the effects of different footwear conditions on the activity of ankle plantar flexors during walking. Ten healthy habitually shod individuals walked overground in shoes, barefoot and in flip-flops while fine-wire electromyography (EMG) activity was recorded from flexor hallucis longus (FHL), soleus (SOL), and medial and lateral gastrocnemius (MG and LG) muscles. EMG signals were peak-normalised and analysed in the stance phase using Statistical Parametric Mapping (SPM). We found highly individual EMG patterns. Although walking with shoes required higher muscle activity for propulsion than walking barefoot or with flip-flops in most participants, this did not result in statistically significant differences in EMG amplitude between footwear conditions in any muscle (p>0.05). Time to peak activity showed the lowest coefficient of variation in shod walking (3.5, 7.0, 8.0 and 3.4 for FHL, SOL, MG and LG, respectively). Future studies should clarify the sources and consequences of individual EMG responses to different footwear.
... Recent evidence suggests that plantar fasciitis could be related to weak foot muscles that are not strong enough to provide foot stability, thus increasing strain in the plantar fascia, which wraps around the MTP joints, presumably affecting their stability 27 . Several lines of evidence suggest that weak foot muscles may be partly a consequence of features in modern shoes that support the longitudinal arch and passively stiffen the foot 21,28,29 . As these studies showed, individuals who habitually wear minimal footwear have intrinsic foot muscles with large cross sectional areas and dynamically stiffer longitudinal arches than individuals who habitually wear modern shoes. ...
Although most features of modern footwear have been intensively studied, there has been almost no research on the effects of toe springs. This nearly ubiquitous upward curvature of the sole at the front of the shoe elevates the toe box dorsally above the ground and thereby holds the toes in a constantly dorsiflexed position. While it is generally recognized that toe springs facilitate the forefoot's ability to roll forward at the end of stance, toe springs may also have some effect on natural foot function. This study investigated the effects of toe springs on foot biomechanics in a controlled experiment in which participants walked in specially-designed sandals with varying curvature in the toe region to simulate toe springs ranging from 10 to 40 degrees of curvature. Using inverse dynamics techniques, we found that toe springs alter the joint moments and work at the toes such that greater degrees of toe spring curvature resulted in lower work requirements during walking. Our results help explain why toe springs have been a pervasive feature in shoes for centuries but also suggest that toe springs may contribute to weakening of the foot muscles and possibly to increased susceptibility to common pathological conditions such as plantar fasciitis.
... Vorfußlaufen eliminiert die maximale Stoßbelastung in den vertikalen Bodenreaktionskräften und verringert im Vergleich zum Auftreten mit dem Rückfuß die Belastungsrate, indem die effektive Masse beim Bodenkontakt durch exzentrisch kontrollierte Extension im Sprunggelenk (Dorsalflexion) reduziert wird [26]. Eine wirkungsvolle Methode, um den Sportler an ein stärker auf den Vorderfuß konzentriertes Laufmuster zu gewöhnen, besteht darin, ihn barfuß oder in ungedämpften Barfußschuhen trainieren zu lassen. ...
Vor allem Läufer kennen das Problem: völlig unvermittelt bekommen sie Beschwerden, die so stark sind, dass sie nicht mehr weitermachen können. Im schlimmsten Fall leiden sie an den schmerzhaften Folgen einer Stressfraktur. Wer im Training die richtigen Reize setzt, kann das Risiko für derartige Verletzungen deutlich verringern.
... The exercise programme was likely insufficient for hypertrophy/strength gains [20], but it remains unknown, as there was no measurement of IFM structure and/or strength. Two other studies in healthy populations, have reported increased IFM size (10-21%) and strength (35-106%) with a programme that involved more than two foot exercises, at higher intensities and larger volumes [21,22]. IFM training with sufficient volume, intensity and progression may produce more beneficial results in PHP compared to previous trials. ...
Background:
Plantar heel pain (PHP) is present in a wide range of individuals and creates significant burden to quality of life and participation in physical activity. The high recurrence rates and persistence of PHP suggests current management options may not address all potentially modifiable factors associated with the condition. Reports of intrinsic foot muscle (IFM) atrophy in individuals with PHP, together with biomechanical evidence of their important contribution to optimal foot function, suggests that an intervention focused on IFM training may be beneficial in managing PHP. We will test the feasibility of a prospective, assessor-blinded, parallel-group, randomised clinical trial that compares foot exercise plus education to brief advice in individuals with PHP.
Methods:
Twenty participants with PHP will be randomly allocated to one of two groups for a 12-week intervention period: (i) foot exercise plus education, or (ii) brief advice. The foot exercise plus education group will attend eight sessions with a physiotherapist and receive detailed education on self-management strategies as well as a progressive exercise program for the IFMs. The brief advice group will attend one session with a physiotherapist and receive brief information about self-management strategies and reassurance. Outcome measures will be obtained at baseline and the primary end-point of 12 weeks. Primary outcomes will be the feasibility of conducting a full-scale randomised clinical trial (RCT), and the credibility and acceptability of the foot exercise plus education intervention. Secondary outcomes will explore treatment effects, which will consist of pain, physical function, physical activity level, pain self-efficacy, perceived treatment effect, magnetic resonance and ultrasound image measurement of IFM morphology, ultrasound imaging measurement of plantar fascia thickness, IFM motor performance, foot posture, foot mobility, ankle dorsiflexion range of motion, toe flexor and plantar flexor strength/endurance.
Discussion:
To reduce the burden of PHP on individuals and society, there is a need to establish effective treatments that are feasible and accepted by patients and health professionals. This trial will be the first to evaluate the feasibility of conducting a full-scale RCT, as well as the credibility, acceptability, and treatment effects, of education and foot exercise for PHP. The findings of this study will inform the development of a full-scale RCT.
Trial registration:
The trial protocol was prospectively registered with the Australia and New Zealand Clinical Trial Registry (ACTRN12619000987167) on 11th July 2019.
... The changes observed were equivalent to that seen with a strengthening programme undertaken for the same duration 68 and are sufficient to alter propulsive forces during running. 50 Therefore, it may be advisable for runners to engage in a foot strengthening programme in tandem with an increase in barefoot activities. ...
Understanding the current prevalence and incidence of running injury from an evolutionary perspective has sparked great debate. Proponents of the evolutionary approach to understanding running injury suggest that humans ran using less injurious biomechanics prior to the invention of cushioned running shoes. Those who disagree with this view, point to the many runners, wearing cushioned running shoes, who do not get injured and suggest that the evolutionary approach is indulging in a ‘natural fallacy’. This polarises the scientific debate into discrete categories such as ‘shod’ vs ‘barefoot’. This review aims, first, to describe humans’ innate impact moderating mechanisms which arise from our evolutionary legacy. Second, we discuss the impact of footwear on these mechanisms and the potential link to injury in some runners. Finally, we discuss the role of barefoot training in sports medicine and attempt to make some practical suggestions as to how it might be integrated in our modern urban environments.
... Measurement methodology was based on two previously published papers [37,38] performed on healthy subjects, and we refer the reader to these papers for additional methodology details, particularly on the intrinsic muscles (FHB, AH, FDB, and QP). Briefly, for these muscles, the participant was seated with the hip flexed and externally rotated, with the knee at 90°and ankle at 30°plantarflexion. ...
Background. Tracking progression of diabetic peripheral polyneuropathy (DPN) is usually focused on sensory nerves and subjective testing methods. Recent studies have suggested that distal muscle atrophy may precede sensation loss. Methods to objectively measure distal muscle size and strength are needed to help understand how neuropathy affects muscle function. Purpose. To evaluate individual intrinsic and extrinsic foot muscle sizes and functional foot strength in participants with DPN. Methods. Thirty individuals participated in this cross-sectional study (15 DPN and 15 matched controls). Sizes of 10 separate muscles of the lower leg and foot were measured using ultrasound imaging. Functional foot strength was also quantified using custom great toe and lateral toe flexion tests along with a doming test. Muscle size and strength metrics were compared between groups using ANOVAs and paired t-tests (α=0.05). Correlations between strength and relevant muscle sizes were also evaluated. Results. The sizes of all four intrinsic foot muscles were smaller in individuals with DPN (p≤0.03), while only one (toe extensor) of the six extrinsic muscles was smaller (p
... It has been shown that when plantar surface afferents are anaesthetised, the maintenance of stability in quiet stance is impaired (Meyer et al., 2004). Due to their design features i.e. cushioning and higher heels, use of conventional shoes is thought to lead to a diminished capacity to detect information from the soles of the feet during interactions with external environments (Ridge et al., 2018). In contrast, research suggests that minimal footwear might improve stimulation of plantar mechanoreceptors compared to conventional shoes (Franklin et al., 2018), enhancing postural responses. ...
Background:
Effects of minimal shoes on stability and physical function in older people are under-researched. No studies have systematically explored effects of a range of minimal footwear features on these factors in older people.
Methods:
A within-participant repeated-measures design was used. Participants were subjected to thirteen footwear conditions: (i) barefoot, (ii) a conventional shoe, (iii) a control minimal shoe, (iv-xiii) minimal shoes differing from the control minimal shoe by one design feature. The outcomes were: (i) postural stability expressed with movement of the center of pressure (CoP) during standing (ii) dynamic stability expressed with the CoP movement during walking, (iv) physical function assessed with the Timed Up and Go test (TUG), and (iv) perceptions of footwear assessed with the Monitor Orthopaedic Shoes questionnaire. Linear Mixed Models were applied for statistical analyses.
Findings:
Twenty-two people participated in the study. Compared to the conventional shoe, participants: (i) were more stable during standing and walking in the majority of minimal shoes, and (ii) completed the TUG test faster when wearing the minimal shoe with wider sole. Compared to the control minimal shoe, participants: (i) completed the TUG test faster when wearing the minimal shoe with wider sole; and (ii) perceived features such as a split toe and a higher ankle collar as less fashionable and wearable.
Interpretation:
Wearing minimal shoes might be more beneficial for stability and physical function in older adults than wearing conventional shoes. The results will be highly valuable for the design of minimal footwear for older adults.
... Modern minimal shoes are designed to mimic barefoot gait, eliminating any support or cushioning. Studies of adults transitioning to minimal shoes in both walking and running have demonstrated increases in the size and strength of their arch muscles (9,46). In addition, those habituated to minimal shoes for running may be less likely to rearfoot strike, and this can promote softer landings. ...
Youth running is defined as participation below age 18. Jumping/multidirectional loading sports (soccer, basketball) may optimize bone health. Psychological development requires monitoring to reduce risk of injuries and burnout. Adequate energy availability is essential for health; screening for disordered eating and optimizing nutrition is important. Injuries during growth spurts are best addressed by identifying the physical maturity of the runner and conventional treatment. Appropriate start of competition and competition distance should be individualized rather than using age-based recommendations and requires careful monitoring. Promoting foot strength and reducing landing impacts may lower injury risk.
... Training the foot through use of minimal footwear (Goldmann, Potthast, & Brüggemann, 2013;Miller, Whitcome, Lieberman, Norton, & Dyer, 2014;Ridge et al., 2019) or resistance exercises (Goldmann, Sanno, et al., 2013;Hashimoto & Sakuraba, 2014) has been shown to increase strength and cross-sectional area of the IFM. Two previous studies have investigated the effects of increased toe-flexor strength on athletic performance Hashimoto & Sakuraba, 2014). ...
The intrinsic foot musculature (IFM) supports the arches of the foot and controls metatarsophalangeal joint (MTPJ) motion. Stronger IFM can increase the effective foot length, potentially altering lower-extremity gearing similar to that of using carbon-fibre-plated footwear. The purpose of this study was to investigate if strengthening of the IFM can alter gait mechanics and improve running economy. Eleven participants were randomly assigned into an experimental group and nine into a control group. The experimental group performed IFM strengthening exercises for ten weeks. Toe-flexor strength, gait mechanics, and running economy were assessed at baseline, five weeks, and ten weeks; using a custom strength testing apparatus, motion capture and force-instrumented treadmill, and indirect calorimetry. Toe-flexor strength increased in the experimental group (p = .006); however, MTPJ and ankle mechanics and running economy did not change. The dearth of changes in mechanics may be due to a lack of mechanical advantage of the IFM, runners staying within their preferred movement path, a need for MTPJ dorsiflexion to facilitate the windlass mechanism, or the primary function of the IFM being to support the longitudinal arch of the foot as opposed to modulating MTPJ mechanics.
... Indeed, intervention studies have shown consistent changes across individuals after walking or running barefoot or in minimal footwear for several weeks. These changes include increased strength and size of foot muscles, increased foot and leg stiffness, and greater use of the spring-like function of the medial longitudinal arch (Brüggemann et al., 2005;Chen et al., 2016;De Wit et al., 2000;Johnson et al., 2015;Miller et al., 2014;Perl et al., 2012;Ridge et al., 2018). ...
Objective: This study aims to explore the effects of a 12-week gait retraining program combined with foot core exercise on arch morphology, arch muscles strength, and arch kinematics. Methods: A total of 26 male recreational runners with normal arch structure who used rear-foot running strike (RFS) were divided into the intervention group (INT group) and control group (CON group) (n = 13 in each group). The INT group performed a 12-week forefoot strike (FFS) training combined with foot core exercises. The CON group did not change the original exercise habit. Before and after the intervention, the arch morphology, as well as the strength of hallux flexion, lesser toe flexion, and the metatarsophalangeal joint (MPJ) flexors were measured in a static position, and changes in the arch kinematics during RFS and FFS running were explored. Results: After a 12-week intervention, 1) the normalized navicular height increased significantly in the INT group by 5.1% (p = 0.027, Cohen's d = 0.55); 2) the hallux absolute flexion and relative flexion of the INT group increased significantly by 20.5% and 21.7%, respectively (p = 0.001, Cohen's d = 0.59; p = 0.001, Cohen's d = 0.73), the absolute and relative strength of the MPJ flexors of the INT group were significantly improved by 30.7% and 32.5%, respectively (p = 0.006, Cohen's d = 0.94; p = 0.006, Cohen's d = 0.96); 3) and during RFS, the maximum arch angle of the INT group declined significantly by 5.1% (p < 0.001, Cohen's d = 1.49), the arch height at touchdown increased significantly in the INT group by 32.1% (p < 0.001, Cohen's d = 1.98). Conclusion: The 12-week gait retraining program combined with foot core exercise improved the arch in both static and dynamic positions with a moderate to large effect size, demonstrating the superiority of this combined intervention over the standalone interventions. Thus, runners with weak arch muscles are encouraged to use this combined intervention as an approach to enhance the arch.
Interest in investigating the use of minimalist footwear (MF) has grown exponentially in recent years. This article systematically reviews the benefits of minimalist footwear for physical fitness, biomechanical factors, and injury incidence in middle- and long-distance runners. A systematic review of PubMed and FECYT (Web of Sciences, CCC, DIIDW, KJD, MEDLINE, RSCI, and SCIELO) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines before 26 April of 2022. From the 583 studies initially found, 23 were included in the qualitative synthesis. The use of MF induces improvements in running economy and stride frequency in middle- and long-distance races, as well as a reduction in the oscillations of runners´ center of gravity and support time. From a biomechanical viewpoint, MF enhances forefoot support increases knee stability, leading to greater foot and ankle mobility. In addition, MF reduces impact load at knee joint.
Flat-flexible shoes with unique characteristics, such as low pitch and flexibility, can increase the efficiency of ankle energy and running performance. If flat-flexible shoes have the same effect during walking, they could be used for gait training. This study aimed to investigate the effects of flat-flexible shoes on the kinematics and kinetics of the lower limb. Twenty-one healthy young adults (21.8 ± 4.6 years) participated in this study. The participants wore flat-flexible and standard athletic shoes with reflective markers attached according to the Plug-in-Gait model. Walking motion was recorded using infrared cameras and a treadmill embedded with force plates. The angle(s), moment(s), and power(s) of the ankle, knee, and hip joints were calculated. Paired t-test and Wilcoxon’s signed-rank test were used to compare the parameters between the two footwear types. The use of flat-flexible shoes increased maximum ankle dorsiflexion and knee flexion angles. The maximum ankle plantar flexion angle was significantly reduced. There was no significant difference in the joint moment between the two footwear types. The peaks of ankle power absorption in late stance, ankle power generation, and hip power generation significantly increased with the use of flat-flexible shoes. These results suggest that flat-flexible shoes have potential as a tool to promote ankle energy storage and release during gait.
Background:
Weakness and disuse of intrinsic foot muscles contributes to dysfunction in foot and toe alignment and sensory input, which may lead to instability and falls in older adults. The aim of this systematic review was to report the effects of intrinsic foot muscle strengthening (IFMS) interventions on functional mobility in adults aged ≥65 years.
Methods:
A systematic review was performed with searches from December 2019-February 2021 using MEDLINE, CINAHL, SPORTDiscus, Rehab and Sports Medicine Source, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials. Additional sources were sought using reference scanning. Eligible sources analyzed adults aged ≥65 years (n = 1674) who were ambulatory, used a functional mobility outcome measure, and contained foot and ankle interventions that included IFMS. Literature studies regarding neurological, vestibular, cognitive, amputation, or post-surgical conditions were excluded. Studies that did not specify intrinsic foot muscle involvement were excluded. Two authors extracted relevant studies and appraised them using the Physiotherapy Evidence Database (PEDro) scale.
Results:
A total of 1420 articles were screened for relevance, and 16 were extracted. Five additional sources were obtained through reference scanning. Nine articles were eligible for review. PEDro scores ranged from 3 to 7 (out of 10), indicating "fair" quality of evidence. Heterogeneity of methods and data did not allow for statistical comparison. Themes extracted from sources were types of intrinsic foot strengthening interventions and parameters; outcomes on falls, balance, functional mobility; and subjective reports regarding functional mobility.
Conclusion:
Evidence reviewed was of fair quality. IFMS interventions contributed to improvements in strength, balance, mobility, and possibly reduced fall risk. There was little effect on gait. Subjective reports indicate a possible mechanism for improved mobility may be from increased proprioception and sensation.
Metatarsal bone stress injuries (BSI) are common in athletic populations. BSIs are overuse injuries that result from an accumulation of microdamage that exceeds bone remodeling. Risk for metatarsal BSI is multifactorial and includes factors related to anatomy, biology and biomechanics. In this paper, anatomical factors including foot type, metatarsal lengths, bone density, bone geometry, and intrinsic muscle strength, which each influence how the foot responds to load, are discussed. Biological factors such as low energy availability and impaired bone metabolism influence the quality of the bone. Finally, the influence of biomechanical loads to bone such as peak forces, load rates, and loading cycles are reviewed. General management of metatarsal BSI is discussed, including acute care, rehabilitation, treatment of refractory metatarsal BSI, and evaluation of healing/return to sport. Finally, we identify future research priorities and emerging treatments for metatarsal BSI.
This article is protected by copyright. All rights reserved.
Objectives
The tibialis posterior (TP) is a vital muscle for controlling the medial longitudinal arch of the foot during weight‐bearing activities. Dysfunction of this muscle is associated with a variety of pathologic conditions; thus, it is important to reliably assess its morphologic characteristics. Ultrasound (US) has been used to assess characteristics of TP tendons but not the muscle cross‐sectional area (CSA). The purpose of this study was to establish a reliable US technique to measure the TP CSA and thickness.
Methods
Twenty‐three healthy volunteers participated. We evaluated the CSA and thickness at 4 measurement locations (anterior and posterior views at both 30% and 50% of the shank length).
Results
The participants included 12 female and 11 male volunteers (mean age ± SD, 31.23 ± 14.93 years). Excellent reliability was seen for the CSA and thickness at all locations (intraclass correlation coefficients, 0.988–0.998). Limits of agreement (LoA) and standard errors of the measurement (SEMs) were slightly lower at the 30% locations (LoA at 30%, 4.6–9.2; LoA at 50%, 6.4–9.7; SEM at 30%, 0.03–0.05; SEM at 50%, 0.04–0.07). Strong correlations were seen between anterior and posterior measurements of the CSA (30%, r = 0.99; P < .0001; 50%, r = 0.94; P < .0001) and thickness (30%, r = 0.98; P < .0001; 50%, r = 0.95; P = .0001).
Conclusions
Based on these results, the TP can be measured accurately with US at any of the tested locations. Due to the ease of collection and the quality of the data, we recommend the anterior view at 30% of the shank length to measure the CSA. The ability to assess muscle size of the TP will aid in a variety of medical and research applications.
Exercise related leg pain in the military. Treatment of MTSS and CECS, with an emphasis on gait retraining.
Objectives:
Foot and leg muscle strength and size are crucial to proper function. It is important to assess these characteristics reliably. Our primary objective was to compare the measurement of still images to cine loops. The secondary purpose was to determine interoperator and intraoperator reliability between operators of different experience levels using video clips and internal and external landmarks.
Methods:
Twelve healthy volunteers participated in our study. Internal (navicular tuberosity) and external (lateral leg length at 30% and 50% from the knee joint line) landmarks were used. Two operators each captured and later measured still and cine loop images of selected foot and leg muscles.
Results:
The 12 participants included 8 male and 4 female volunteers (mean age ± SD, 23.5 ± 1.9 years). Good to excellent intraoperator and interoperator reliability was seen (intraclass correlation coefficient range of 0.946-0.998). The use of cine loops improved the intraclass correlation coefficients for both intraoperator and interoperator reliability (0.5%-4% increases). The use of cine loops decreased the intraoperator standard error of the measurement and limits of agreement of the novice operator (decreases of 45%-73% and 24%-51%, respectively), and these became comparable to those of experienced operators using still images. The interoperator standard errors of the measurement dropped by 42% to 53%, whereas the limits of agreement dropped by 27% to 40%. No substantial changes were noted in the tibialis anterior across reliability metrics.
Conclusions:
Improved protocols that take advantage of using internal bony landmarks and cine loops during both the image-gathering and measurement processes improve the reliability of research examining muscle size changes in the lower leg or foot associated with muscle changes due to exercise, injury, disuse, or disease.
INTRODUCTION : La course à pied est une pratique sportive avec un nombre croissant de pratiquants du à sa facilité d’accès et la prise de conscience de l’intérêt de l’activité physique. Cette augmentation du nombre de sportifs entraîne des pathologies. La fasciopathie plantaire est la troisième pathologie la plus représentée chez le coureur à pied touchant près de 10% de ces athlètes. Cependant, il n’existe pas de traitement spécifique à cette pathologie.
OBJECTIF : Réaliser un constat des différentes techniques rééducatives efficaces et prouvées que le masseur-kinésithérapeute peut mettre en oeuvre pour un traitement optimal des coureurs atteints de fasciopathie plantaire.
METHODE : Une revue systématique de la littérature a été menée à travers l’interrogation de trois bases de données scientifiques en santé (PubMed, ScienceDirect, LiSSa). L’évaluation méthodologique des articles inclus est réalisée avec l’échelle PEDro.
RESULTATS : 8 études correspondent aux critères d’inclusions et sont intégrées dans notre revue sur une base de 802 articles. Tous ces essais sont de bonne qualité méthodologique sur la grille PEDro. Trois essais contrôlés randomisés étudient l’efficacité des ondes de choc (ODC), deux à propos du laser de basse intensité (LLLT), un sur le renforcement musculaire des muscles du pied et de la hanche, un sur la mobilisation articulaire du pied et de la cheville et un au sujet du dry needling électrique. Les résultats semblent montrer l’efficacité des traitements combinés, ainsi que des ondes de choc face à un placebo.
CONCLUSION : La combinaison de plusieurs traitements conservatifs montre son efficacité sur la douleur et la fonction du pied. De plus, les ondes de choc ont montré leur efficacité face à un placebo. Il reste tout de même des questionnements sur les modalités d’application de ces thérapies ainsi que sur le traitement spécifique du coureur à pied.
Mots-clés :
- Course à pied
- Fasciopathie plantaire
- Rééducation
INTRODUCTION : La course à pied est une pratique sportive avec un nombre croissant de pratiquants du à sa facilité d’accès et la prise de conscience de l’intérêt de l’activité physique. Cette augmentation du nombre de sportifs entraîne des pathologies. La fasciopathie plantaire est la troisième pathologie la plus représentée chez le coureur à pied touchant près de 10% de ces athlètes. Cependant, il n’existe pas de traitement spécifique à cette pathologie.
OBJECTIF : Réaliser un constat des différentes techniques rééducatives efficaces et prouvées que le masseur-kinésithérapeute peut mettre en oeuvre pour un traitement optimal des coureurs atteints de fasciopathie plantaire.
METHODE : Une revue systématique de la littérature a été menée à travers l’interrogation de trois bases de données scientifiques en santé (PubMed, ScienceDirect, LiSSa). L’évaluation méthodologique des articles inclus est réalisée avec l’échelle PEDro.
RESULTATS : 8 études correspondent aux critères d’inclusions et sont intégrées dans notre revue sur une base de 802 articles. Tous ces essais sont de bonne qualité méthodologique sur la grille PEDro. Trois essais contrôlés randomisés étudient l’efficacité des ondes de choc (ODC), deux à propos du laser de basse intensité (LLLT), un sur le renforcement musculaire des muscles du pied et de la hanche, un sur la mobilisation articulaire du pied et de la cheville et un au sujet du dry needling électrique. Les résultats semblent montrer l’efficacité des traitements combinés, ainsi que des ondes de choc face à un placebo.
CONCLUSION : La combinaison de plusieurs traitements conservatifs montre son efficacité sur la douleur et la fonction du pied. De plus, les ondes de choc ont montré leur efficacité face à un placebo. Il reste tout de même des questionnements sur les modalités d’application de ces thérapies ainsi que sur le traitement spécifique du coureur à pied.
Mots-clés :
- Course à pied
- Fasciopathie plantaire
- Rééducation
Background: The goal was to examine the feasibility of a randomized controlled trial (RCT) on the effect of a therapeutic foot-ankle training program to prevent injury in long-distance runners. First, we evaluated (i) the access to participants and recruitment success; (ii) participants’ satisfaction and adherence to the program; (iii) the effect of the training program to improve foot muscle strength and change foot biomechanics; and, second, we used the collected data for a post hoc sample size calculation. Methods/design: We randomized 31 healthy long-distance recreational runners to either an 8-week foot-ankle muscle strength-training program (intervention) or a stretching protocol (control). The recruitment rate was the number of eligible participants per week of recruitment; recruitment success, the ratio between scheduled baseline visits and initially eligible participants. Participant satisfaction was assessed by a questionnaire, and adherence to the training program was recorded in a Web-based software, both at the 8-week mark. Program effect was assessed by hallux and toe muscle strength using a pressure platform, foot muscle cross-sectional area using magnetic resonance imaging and foot kinematics during running using 3D gait analysis; assessments were done at baseline and after 8 and 16 weeks. A post hoc power analysis was performed on foot strength and the biomechanical data was collected. Results: In two weeks of recruitment, 112 initially eligible subjects were screened, 81 of whom were deemed eligible and 31 had a baseline study visit, giving a recruitment rate of 40.5 subjects/week and recruitment success of 28%. Participants’ adherence was 97%, and satisfaction scored a median >3 out of 5 on a Likert scale on all questions. The cross-sectional area of the abductor hallucis (P = 0.040) and flexor digitorum brevis (P = 0.045) increased significantly at 8 weeks in the intervention group. The post hoc sample sizes for almost all the strength and biomechanical parameters were below those of the 112 subjects calculated as the original sample size for clinical outcome (running-related injury). Conclusion: Results show that this RCT is feasible, given an accessible study population that is willing to participate and that perceives the training program as positive and adheres to the program. The training program leads to several positive outcomes on muscle strength that justifies assessing clinical outcomes in this RCT.
Despite substantial recent interest in walking barefoot and in minimal footwear, little is known about potential differences in walking biomechanics when unshod versus minimally shod. To test the hypothesis that heel impact forces are similar during barefoot and minimally shod walking, we analysed ground reaction forces recorded in both conditions with a pedography platform among indigenous subsistence farmers, the Tarahumara of Mexico, who habitually wear minimal sandals, as well as among urban Americans wearing commercially available minimal sandals. Among both the Tarahumara (n = 35) and Americans (n = 30), impact peaks generated in sandals had significantly (p < 0.05) higher force magnitudes, slower loading rates and larger vertical impulses than during barefoot walking. These kinetic differences were partly due to individuals’ significantly greater effective mass when walking in sandals. Our results indicate that, in general, people tread more lightly when walking barefoot than in minimal footwear. Further research is needed to test if the variations in impact peaks generated by walking barefoot or in minimal shoes have consequences for musculoskeletal health.
The longitudinal arch (LA) helps stiffen the foot during walking, but many people in developed countries suffer from flat foot, a condition characterized by reduced LA stiffness that can impair gait. Studies have found this condition is rare in people who are habitually barefoot or wear minimal shoes compared to people who wear conventional modern shoes, but the basis for this difference remains unknown. Here we test the hypothesis that the use of shoes with features that restrict foot motion (e.g. arch supports, toe boxes) is associated with weaker foot muscles and reduced foot stiffness. We collected data from minimally-shod men from northwestern Mexico and men from urban/suburban areas in the United States who wear 'conventional' shoes. We measured dynamic LA stiffness during walking using kinematic and kinetic data, and the cross-sectional areas of three intrinsic foot muscles using ultrasound. Compared to conventionally-shod individuals, minimally-shod individuals had higher and stiffer LAs, and larger abductor hallucis and abductor digiti minimi muscles. Additionally, abductor hallucis size was positively associated with LA stiffness during walking. Our results suggest that use of conventional modern shoes is associated with weaker intrinsic foot muscles that may predispose individuals to reduced foot stiffness and potentially flat foot.
Background
Quantifying the strength of the intrinsic foot muscles has been a challenge for clinicians and researchers. The reliable measurement of this strength is important in order to assess weakness, which may contribute to a variety of functional issues in the foot and lower leg, including plantar fasciitis and hallux valgus. This study reports 3 novel methods for measuring foot strength – doming (previously unmeasured), hallux flexion, and flexion of the lesser toes.
Methods
Twenty-one healthy volunteers performed the strength tests during two testing sessions which occurred one to five days apart. Each participant performed each series of strength tests (doming, hallux flexion, and lesser toe flexion) four times during the first testing session (twice with each of two raters) and two times during the second testing session (once with each rater). Intra-class correlation coefficients were calculated to test for reliability for the following comparisons: between raters during the same testing session on the same day (inter-rater, intra-day, intra-session), between raters on different days (inter-rater, inter-day, inter-session), between days for the same rater (intra-rater, inter-day, inter-session), and between sessions on the same day by the same rater (intra-rater, intra-day, inter-session).
Results
ICCs showed good to excellent reliability for all tests between days, raters, and sessions. Average doming strength was 99.96 ± 47.04 N. Average hallux flexion strength was 65.66 ± 24.5 N. Average lateral toe flexion was 50.96 ± 22.54 N.
Conclusions
These simple tests using relatively low cost equipment can be used for research or clinical purposes. If repeated testing will be conducted on the same participant, it is suggested that the same researcher or clinician perform the testing each time for optimal reliability.
Objective: Foot and ankle exercise has been advocated as a preventative approach in reducing the risk of foot ulceration. However, knowledge about the appropriate types and intensity of exercise program for diabetic foot ulcer prevention is still limited. The current study aimed to examine the effects of an eight-week mini-trampoline exercise on improving foot mobility, plantar pressure and sensation of diabetic neuropathic feet.
Methods: Twenty-one people with diabetic peripheral neuropathy who had impaired sensation perception were divided into two groups. The exercise group received a foot-care education program plus an eight-week home exercise program using the mini-trampoline (n = 11); whereas a control group received a foot-care education only (n = 10). Measurements were undertaken at the beginning, at the completion of the eight-week program and at a 20-week follow-up.
Results: Both groups were similar prior to the study. Subjects in the exercise group significantly increased the range of the first metatarsophalangeal joint in flexion (left: p = 0.040, right: p = 0.012) and extension (left: p = 0.013) of both feet more than controlled subjects. There was a trend for peak plantar pressure at the medial forefoot to decrease in the exercise group (p = 0.016), but not in the control group. At week 20, the number of subjects in the exercise group who improved their vibration perception in their feet notably increased when compared to the control group (left: p = 0.043; right: p = 0.004).
Conclusions: This is a preliminary study to document the improvements in foot mobility, plantar pressure and sensation following weight-bearing exercise on a flexible surface in people with diabetic neuropathic feet. Mini-trampoline exercise may be used as an adjunct to other interventions to reduce risk of foot ulceration. A larger sample size is needed to verify these findings. This trial is registered with COA No. 097.2/55.
Increases in muscle size and strength are influenced by the mechanical and metabolic stresses imposed by resistance training. Mechanical stress is induced by the use of high-intensity training and it is believed it activates a larger percentage of muscle fibers. Conversely, metabolic stress is generated by high training volumes with moderate intensities using short rest intervals. This training paradigm results in greater fatigue and potentially stimulates a greater anabolic hormone response to exercise. Although evidence exists for both strategies, it still remains inconclusive whether one training paradigm is more advantageous than the other regarding muscle hypertrophy development. In untrained adults, the novelty of most resistance training programs may be sufficient to promote hypertrophy and strength gains, whereas greater training intensity may be more beneficial for trained adults. However, the body of well-designed research in this advanced population is limited. Therefore, the purpose of this brief review is to discuss the merits and limitations of the current evidence. © 2015, University of Zagreb - Faculty of Kinesiology. All rights reserved.
Efforts have been made to retard the progressive debilitating pain and joint dysfunction in patients with knee osteoarthritis. We aimed to evaluate the therapeutic effect of a low-cost minimalist footwear on pain, function, clinical and gait-biomechanical aspects of elderly women with knee osteoarthritis.
Throughout a randomized, parallel and controlled clinical trial, fifty-six patients with medial knee osteoarthritis were randomly allocated to an intervention (n=28) or control group (n=28), and assessed at baseline and after three and six months. The intervention involved wearing Moleca(®) footwear for at least 6h/day, 7days/week, over 6months. The pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index was the primary outcome. The secondary outcomes were the other subscales, Lequesne score, distance walked in 6 min, knee oedema and effusion, knee adduction moment and paracetamol intake. Intention-to-treat analysis was performed using two-way casewise ANOVA (< .05) and Cohen's d coefficient.
Intervention group showed improvement in pain (effect size: 1.41, p<.001), function (effect size: 1.22, p=.001), stiffness (effect size: 0.76, p=.001), Lequesne score (effect size: 1.07, p<.001), and reduction by 21.8% in the knee adduction moment impulse (p=.017) during gait wearing Moleca(®). The analgesic intake was lower in the intervention group.
The long-term use of Moleca(®) footwear relieves pain, improves self-reported function, reduces the knee loading while wearing Moleca(®), refrains the increase of analgesic intake in elderly women with knee osteoarthritis and can be considered as a conservative mechanical treatment option. ClinicalTrials.gov (NCT01342458).
Copyright © 2015 Elsevier Ltd. All rights reserved.
The human foot undergoes complex deformations during walking due to passive tissues and active muscles. However, based on prior recordings it is unclear if muscles that contribute to flexion/extension of the metatarsophalangeal (MTP) joints are activated synchronously to modulate joint impedance, or sequentially to perform distinct biomechanical functions. We investigated the coordination of MTP flexors and extensors with respect to each other, and to other ankle-foot muscles.
We analyzed surface electromyographic (EMG) recordings of intrinsic and extrinsic foot muscles for healthy individuals during level treadmill walking, and also during sideways and tiptoe gaits. We computed stride-averaged EMG envelopes and used the timing of peak muscle activity to assess synchronous vs. sequential coordination.
We found that peak MTP flexor activity occurred significantly before peak MTP extensor activity during walking (P < 0.001). The period around stance-to-swing transition could be roughly characterized by sequential peak muscle activity from the ankle plantarflexors, MTP flexors, MTP extensors, and then ankle dorsiflexors. We found that foot muscles that activated synchronously during forward walking tended to dissociate during other locomotor tasks. For instance, extensor hallucis brevis and extensor digitorum brevis muscle activation peaks decoupled during sideways gait.
The sequential peak activity of MTP flexors followed by MTP extensors suggests that their biomechanical contributions may be largely separable from each other and from other extrinsic foot muscles during walking. Meanwhile, the task-specific coordination of the foot muscles during other modes of locomotion indicates a high-level of specificity in their function and control.
Background:
Despite the prevalence and impact of plantar heel pain, its etiology remains poorly understood, and there is no consensus regarding optimum management. The identification of musculoskeletal factors related to the presence of plantar heel pain could lead to the development of better targeted intervention strategies and potentially improve clinical outcomes. The aim of this study was to investigate relationships between a number of musculoskeletal and activity-related measures and plantar heel pain.
Methods:
In total, 202 people with plantar heel pain and 70 asymptomatic control participants were compared on a variety of musculoskeletal and activity-related measures, including body mass index (BMI), foot and ankle muscle strength, calf endurance, ankle and first metatarsophalangeal (MTP) joint range of motion, foot alignment, occupational standing time, exercise level, and generalized hypermobility. Following a comparison of groups for parity of age, analyses of covariance were performed to detect differences between the 2 groups for any of the variables measured.
Results:
The plantar heel pain group displayed a higher BMI, reduced ankle dorsiflexion range of motion, reduced ankle evertor and toe flexor strength, and an altered inversion/eversion strength ratio. There were no differences between groups for foot alignment, dorsiflexor or invertor strength, ankle inversion or eversion range of motion, first MTP joint extension range of motion, generalized hypermobility, occupational standing time, or exercise level.
Conclusion:
Plantar heel pain is associated with higher BMI and reductions in some foot and ankle strength and flexibility measures. Although these factors could be either causal or consequential, they are all potentially modifiable and could be targeted in the management of plantar heel pain.
Level of evidence:
Level III, comparative study.
Background
This prospective study explored the effects of endurance running (ER) in minimal versus standard running shoes on the foot’s superficial layer intrinsic muscles and the function of the longitudinal arch. Our hypothesis was that running in minimal shoes would cause hypertrophy in these muscles and lead to higher, stronger, stiffer arches.
Methods
The hypothesis was tested using a sample of 33 healthy runners randomized into two groups, a control group shod in traditional running footwear and an experimental group shod in minimal support footwear, whose feet were scanned in an MRI before and after a 12-week training regime. Running kinematics as well as arch stiffness and height were also assessed before and after the treatment period.
Results
Analysis of anatomical cross-sectional areas and muscle volumes indicate that the flexor digitorum brevis muscle became larger in both groups by 11% and 21%, respectively, but only the minimally shod runners had significant areal and volumetric increases of the abductor digiti minimi of 18% and 22%, respectively, and significantly increased longitudinal arch stiffness (60%).
Conclusion
These results suggest that endurance running in minimal support footwear with 4 mm offset or less makes greater use of the spring-like function of the longitudinal arch, thus leading to greater demands on the intrinsic muscles that support the arch, thereby strengthening the foot.
Foot musculoskeletal deficits are seldom addressed by preventive medicine despite their high prevalence in patients with diabetic polyneuropathy.
To investigate the effects of strengthening, stretching, and functional training on foot rollover process during gait.
A two-arm parallel-group randomized controlled trial with a blinded assessor was designed. Fifty-five patients diagnosed with diabetic polyneuropathy, 45 to 65 years-old were recruited. Exercises for foot-ankle and gait training were administered twice a week, for 12 weeks, to 26 patients assigned to the intervention group, while 29 patients assigned to control group received recommended standard medical care: pharmacological treatment for diabetes and foot care instructions. Both groups were assessed after 12 weeks, and the intervention group at follow-up (24 weeks). Primary outcomes involved foot rollover changes during gait, including peak pressure (PP). Secondary outcomes involved time-to-peak pressure (TPP) and pressure-time integral (PTI) in six foot-areas, mean center of pressure (COP) velocity, ankle kinematics and kinetics in the sagittal plane, intrinsic and extrinsic muscle function, and functional tests of foot and ankle.
Even though the intervention group primary outcome (PP) showed a not statistically significant change under the six foot areas, intention-to-treat comparisons yielded softening of heel strike (delayed heel TPP, p=.03), better eccentric control of forefoot contact (decrease in ankle extensor moment, p<.01; increase in function of ankle dorsiflexion, p<.05), earlier lateral forefoot contact with respect to medial forefoot (TPP anticipation, p<.01), and increased participation of hallux (increased PP and PTI, p=.03) and toes (increase in PTI, medium effect size). A slower COP mean velocity (p=.05), and an increase in overall foot and ankle function (p<.05) were also observed. In most cases, the values returned to baseline after the follow-up (p<.05).
Intervention discreetly changed foot rollover towards a more physiological process, supported by improved plantar pressure distribution and better functional condition of the foot ankle complex. Continuous monitoring of the foot status and patient education are necessary, and can contribute to preserving the integrity of foot muscles and joints impaired by polyneuropathy. Trial registration: ClinicalTrials.gov Identifier: NCT01207284, registered in 20th September 2010.
The foot is a complex structure with many articulations and multiple degrees of freedom that play an important role in static posture and dynamic activities. The evolutionary development of the arch of the foot was coincident with the greater demands placed on the foot as humans began to run. The movement and stability of the arch is controlled by intrinsic and extrinsic muscles. However, the intrinsic muscles are largely ignored by clinicians and researchers. As such, these muscles are seldom addressed in rehabilitation programmes. Interventions for foot-related problems are more often directed at externally supporting the foot rather than training these muscles to function as they are designed. In this paper, we propose a novel paradigm for understanding the function of the foot. We begin with an overview of the evolution of the human foot with a focus on the development of the arch. This is followed by a description of the foot intrinsic muscles and their relationship to the extrinsic muscles. We draw the parallels between the small muscles of the trunk region that make up the lumbopelvic core and the intrinsic foot muscles, introducing the concept of the foot core. We then integrate the concept of the foot core into the assessment and treatment of the foot. Finally, we call for an increased awareness of the importance of the foot core stability to normal foot and lower extremity function.
A specific training program emphasizing the neuromuscular recruitment of the plantar intrinsic foot muscles, colloquially referred to as "short foot" exercise (SFE) training, has been suggested as a means to dynamically support the medial longitudinal arch (MLA) during functional tasks. A single-group repeated measures pre- and post-intervention study design was utilized to determine if a 4-week intrinsic foot muscle training program would impact the amount of navicular drop (ND), increase the arch height index (AHI), improve performance during a unilateral functional reaching maneuver, or the qualitative assessment of the ability to hold the arch position in single limb stance position in an asymptomatic cohort. 21 asymptomatic subjects (42 feet) completed the 4-week SFE training program. Subject ND decreased by a mean of 1.8 mm at 4 weeks and 2.2 mm at 8 weeks (p < 0.05). AHI increased from 28 to 29% (p < 0.05). Intrinsic foot muscle performance during a static unilateral balancing activity improved from a grade of fair to good (p < 0.001) and subjects experienced a significant improvement during a functional balance and reach task in all directions with the exception of an anterior reach (p < 0.05). This study offers preliminary evidence to suggest that SFE training may have value in statically and dynamically supporting the MLA. Further research regarding the value of this exercise intervention in foot posture type or pathology specific patient populations is warranted.
Background
Measuring the strength of individual foot muscles is very challenging; however, measuring muscle morphology has been shown to be associated with strength. A reliable method of assessing foot muscle atrophy and hypertrophy would therefore be beneficial to researchers and clinicians. Thus, the aim of this study was to evaluate the test-retest intra-observer reliability of ultrasound to measure the morphology of the primary toe flexor muscles.
Method
The abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae and abductor digiti minimi muscles in the foot, and the flexor digitorum longus and flexor hallucis longus muscles in the shank were assessed in five males and five females (mean age = 32.1 ± 10.1 years). Muscles were imaged using a GE Venue 40 ultrasound (6-9 or 7.6-10.7 MHz transducer) in a random order, and on two occasions 1-6 days apart. Muscle thickness and cross-sectional area were measured using Image J software with the assessor blinded to muscle and day of scan. Intraclass correlation coefficients (ICC) and limits of agreement were calculated to assess day-to-day repeatability of the measurements.
Results
The method was found to have good reliability (ICC = 0.89-0.99) with limits of agreement between 8-28% of the relative muscle size.
Conclusion
The protocol described in this paper showed that ultrasound is a reliable method to measure morphology of the toe flexor muscles. The portability and advantages of ultrasound make it a useful tool for clinical and research settings.
INTRODUCTION As biological structures receive mechanical stimuli they are getting stronger. If muscles, tendons and bones are not in use they will decrease strength and their functional capacity. The biological structures of the foot can be trained by barefoot walking or workout through the speculated higher loading. No scientific evidence for a causal relationship between in-creased foot loading and functional improvement of foot structures could be found in the literature. The foot arch and the foot functional capacity is strongly related to the strength of the flexor muscles of the metatarsophalangeal joints (MPJ): M. flexor hallucis longus (FHL) and M. flexor digitorum longus (FDL) [1,2,3]. It was shown that a special designed minimal shoe (Nike FREE) increases the range of motion on the metatarsophalangeal joints (MPJ) and the ankle joint in normal walking and modifies the plantar pressure distribution in a way close to barefoot walking on grass. In a pilot study using wire EMG technique the muscle activity of the FHL was shown to be significantly increased during walking in the minimal footwear in comparison to walking in traditional running shoes. If training with the minimal footwear mimics barefoot training one can assume that using the minimal shoe will increase the loading of the foot structures and make them stronger. The purpose of the study was to demonstrate the capacity of biological structures to adapt to mechanical stimuli modified through footwear and to quantify effects on strength and morphology of the foot and shank muscles. The research question was to quantify the impact of increased mechanical stimuli on (1) muscle strength and (2) anatomical cross sec-tional area (ACSA) of intrinsic foot and shank muscles. METHODS The research question was solved by a prospective longitudinal designed approach. The prospective study operated with an experimental (n E =25) and a control group (n C =25) both consisting of male and female subjects. The experimental intervention over a period of five months was the use of the minimal footwear in athletes preparatory (warm up) training while the control group used traditional training shoes for the same training programme. The measurement of muscle strength was performed by special custom build dynamo-meters. ACSA of FHL, FDL, M. triceps surae (TS), Mm. tib. post (TP) and ant.(TA), M. peroneus (PER) at the greatest circumference of the shank and ACSA of four of the intrinsic foot muscles (M. abductor hallucis, M. quadratus plantae, M. abductor digiti minimi, M. flexor digitorum brevis) were estimated by MRI (Siemens Symphony, 1.5 Tesla). RESULTS AND DISCUSSION The muscle strength changes through the intervention showed a significant (p<.01) increase of the MPJ flexors in the experi-mental group; no significant change in the controls.
Polyneuropathy is a complication of diabetes mellitus that has been very challenging for clinicians. It results in high public health costs and has a huge impact on patients' quality of life. Preventive interventions are still the most important approach to avoid plantar ulceration and amputation, which is the most devastating endpoint of the disease. Some therapeutic interventions improve gait quality, confidence, and quality of life; however, there is no evidence yet of an effective physical therapy treatment for recovering musculoskeletal function and foot rollover during gait that could potentially redistribute plantar pressure and reduce the risk of ulcer formation.
A randomised, controlled trial, with blind assessment, was designed to study the effect of a physiotherapy intervention on foot rollover during gait, range of motion, muscle strength and function of the foot and ankle, and balance confidence. The main outcome is plantar pressure during foot rollover, and the secondary outcomes are kinetic and kinematic parameters of gait, neuropathy signs and symptoms, foot and ankle range of motion and function, muscle strength, and balance confidence. The intervention is carried out for 12 weeks, twice a week, for 40-60 min each session. The follow-up period is 24 weeks from the baseline condition.
Herein, we present a more comprehensive and specific physiotherapy approach for foot and ankle function, by choosing simple tasks, focusing on recovering range of motion, strength, and functionality of the joints most impaired by diabetic polyneuropathy. In addition, this intervention aims to transfer these peripheral gains to the functional and more complex task of foot rollover during gait, in order to reduce risk of ulceration. If it shows any benefit, this protocol can be used in clinical practice and can be indicated as complementary treatment for this disease.
ClinicalTrials.gov Identifier: NCT01207284.
To prevent overuse injuries related to excessively pronated feet, the strengthening of the foot intrinsic muscles has been recommended. The purpose of this study was to examine the effects of foot orthoses and a short-foot exercise intervention on the cross-sectional area (CSA) of the abductor hallucis (AbdH) muscle and strength of the flexor hallucis (FH) in subjects with pes planus.
Twenty-eight subjects with pes planus were randomly assigned to the foot orthosis (FO) group or the combined foot orthosis and short-foot exercise (FOSF) group for an 8-week intervention. The CSA of the AbdH muscle and the strength of FH were assessed before and after intervention. Data were analyzed using a mixed-model ANOVA.
Significant group by intervention interaction effects were observed in CSA of the AbdH (p=0.009) and strength of the FH (p=0.015). The results of the post hoc paired t-test showed that that the CSA of the AbdH muscle and the strength of the FH significantly increased after the intervention in both groups (p=0.000). The mean CSA of the AbdH muscle and the strength of FH were significantly greater in subjects in the FOSF group compared with subjects in the FO group (mean difference of FO vs. FOSF=13.61 mm(2) in CSA of AbdH muscle; 0.90 kgf in strength of FH; p=0.008).
Results from this study demonstrate that foot orthoses combined with short-foot exercise is more effective in increasing the CSA of the AbdH muscle and the strength of FH compared with foot orthoses alone. Therefore, foot orthoses combined with short-foot exercise are recommended for improving strength of AbdH muscle in subjects with pes planus.
The Abductor hallucis muscle (AbdH) plays an integral role during gait and is often affected in pathological foot conditions. The aim of this study was to evaluate the within and between-session intra-tester reliability using diagnostic ultrasound of the dorso-plantar thickness, medio-lateral width and cross-sectional area, of the AbdH in asymptomatic adults.
The AbdH muscles of thirty asymptomatic subjects were imaged and then measured using a Philips HD11 Ultrasound machine. Interclass correlation coefficients (ICC) with 95% confidence intervals (CI) were used to calculate both within and between session intra-tester reliability.
The within-session reliability results demonstrated for dorso-plantar thickness an ICC of 0.97 (95% CI: 0.99-0.99); medio-lateral width an ICC: of 0.97 (95% CI: 0.92-0.97) and cross-sectional area an ICC of 0.98 (95% CI: 0.98-0.99). Between-session reliability results demonstrated for dorso-plantar thickness an ICC of 0.97 (95% CI: 0.95 to 0.98); medio-lateral width an ICC of 0.94 (95% CI 0.90 to 0.96) and for cross-sectional area an ICC of 0.79 (95% CI 0.65 to 0.88).
Diagnostic ultrasound has the potential to be a reliable tool for evaluating the AbdH muscle in asymptomatic subjects. Subsequent studies may be conducted to provide a better understanding of the AbdH function in foot and ankle pathologies.
An 8-wk progressive resistance training program for the lower extremity was performed twice a week to investigate the time course for skeletal muscle adaptations in men and women. Maximal dynamic strength was tested biweekly. Muscle biopsies were extracted at the beginning and every 2 wk of the study from resistance-trained and from nontrained (control) subjects. The muscle samples were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain content. In addition, fasting blood samples were measured for resting serum levels of testosterone, cortisol, and growth hormone. With the exception of the leg press for women (after 2 wk of training) and leg extension for men (after 6 wk of training), absolute and relative maximal dynamic strength was significantly increased after 4 wk of training for all three exercises (squat, leg press, and leg extension) in both sexes. Resistance training also caused a significant decrease in the percentage of type IIb fibers after 2 wk in women and 4 wk in men, an increase in the resting levels of serum testosterone after 4 wk in men, and a decrease in cortisol after 6 wk in men. No significant changes occurred over time for any of the other measured parameters for either sex. These data suggest that skeletal muscle adaptations that may contribute to strength gains of the lower extremity are similar for men and women during the early phase of resistance training and, with the exception of changes in the fast fiber type composition, that they occur gradually.
The human forefoot presents an interesting biomechanical problem of clinical importance because loads are distributed unequally across multiple bones. The fact that long bones typically have a several-fold safety factor relative to peak loads suggests that metatarsal strengths should be related to their peak loads. This study is the first to systematically examine the cross-sectional geometric properties of the human forefoot and their relationship to external loads during walking and running. We report midlength cross-sectional geometric properties (CA, Ix, Iy, Imax, Imin, J, Zx, and Zy) of metatarsals (1-5) and the hallucial proximal phalanx of a shod industrial population (n = 40) obtained using computed tomography. We then examine the relationship between these measures of shaft strength and published plantar pressure data sets recorded during the following functional activities: standing, at the push-off stage of the walking cycle, the full walking cycle, and running. Cross-sectional geometric properties of the first ray are greater than those of other rays, even when scaled to bone length. This pattern corresponds to the high pressures recorded for the first ray during most activities. The relationships between cross-sectional geometric properties of the lateral metatarsals and peak plantar pressure data are more complex. Metatarsals 2-4 are weakest in most cross-sectional geometric properties. However, metatarsal 2, and to a lesser extent metatarsal 3, experience relatively high peak pressures. On average, geometric measures of axial and bending strengths (adjusted relative to body size) are lower in females than males, and in European Americans than in African Americans, which corresponds to the respective rates of general metatarsal stress fracture in these groups. The discrepancy between strength and plantar pressure values in metatarsals 2 and 3 is consistent with the high incidence of stress fractures in these bones and underscores the importance of soft tissues, such as the plantar fascia and flexor musculature, in moderating metatarsal shaft strain.
Ageing is associated with changes to the structure and function of the foot and ankle, and there is preliminary evidence that foot problems impair balance and increase the risk of falls. To explore this in more detail, we conducted a study to determine the relative contribution of several foot and ankle characteristics to performance on a range of balance and functional tests.
One hundred seventy-six people (56 men and 120 women, mean age 80.1 years, standard deviation 6.4 years) residing in a retirement village underwent tests of foot and ankle characteristics (including foot posture, range of motion, strength, and deformity), sensorimotor function (including vision, sensation, strength, and reaction time), and balance and functional ability (including tests of standing balance, leaning balance, stepping, sit-to-stand, and walking speed).
Many foot and ankle characteristics and sensorimotor measures were associated with performance on the balance and functional tests in univariate analyses. Multiple regression analysis consistently revealed that ankle flexibility, plantar tactile sensitivity, and toe plantarflexor strength were significant and independent predictors of balance and functional test performance, explaining up to 59% of the variance in these test scores.
Foot and ankle characteristics, particularly ankle flexibility, plantar tactile sensation, and strength of toe plantarflexor muscles, are significant independent predictors of balance and functional ability in older people. Programs to improve the strength and flexibility of the foot and interventions to augment plantar sensation may be beneficial in improving mobility and reducing the risk of falls.
Plantar fasciitis is a prevalent problem, with limited consensus among clinicians regarding the most effective treatment. The purpose of this literature review is to provide a systematic approach to the treatment of plantar fasciitis based on the windlass mechanism model.
We searched MEDLINE, SPORT Discus, and CINAHL from 1966 to 2003 using the key words plantar fasciitis, windlass mechanism, pronation, heel pain, and heel spur.
We offer a biomechanical application for the evaluation and treatment of plantar fasciitis based on a review of the literature for the windlass mechanism model. This model provides a means for describing plantar fasciitis conditions such that clinicians can formulate a potential causal relationship between the conditions and their treatments.
Clinicians' understanding of the biomechanical causes of plantar fasciitis should guide the decision-making process concerning the evaluation and treatment of heel pain. Use of this approach may improve clinical outcomes because intervention does not merely treat physical symptoms but actively addresses the influences that resulted in the condition. Principles from this approach might also provide a basis for future research investigating the efficacy of plantar fascia treatment.
Purpose:
The aim of this research is to assess foot structure, foot function, injury and physical activity levels in Kenyan children and adolescents who are HB compared with those who were habitually shod (HS).
Methods:
Foot structure, function, injury prevalence, and physical activity levels were studied using two studies with equal numbers of HS and HB. HS and HB children and adolescents were matched for age, sex, and body mass. Foot arch characteristics, foot strength, and lower-limb injury prevalence were investigated in Study 1 (n = 76). Heel bone stiffness, Achilles tendon moment arm length and physical activity levels in Study 2 (n=62). Foot muscle strength was measured using a strength device TKK 3360 and heel bone stiffness by bone ultrasonometry. The moment arm length of the Achilles tendon was estimated from photographs and physical activity was assessed using questionnaires and accelerometers.
Results:
Foot shortening strength was greater in HB (4.8 ± 1.9 kg vs 3.5 ± 1.8 kg, P < 0.01). Navicular drop was greater in HB (0.53 ± 0.32 cm vs 0.39 ± 0.19 cm, P < 0.05). Calcaneus stiffness index was greater (right 113.5 ± 17.1 vs 100.5 ± 116.8, P < 0.01 left 109.8 ± 15.7 vs 101.7 ± 18.7, P < 0.05) and Achilles tendon moment arm shorter in HB (right, 3.4 ± 0.4 vs 3.6 ± 0.4 cm, P < 0.05; left, 3.4 ± 0.5 vs 3.7 ± 0.4 cm, P < 0.01). Lower-limb injury prevalence was 8% in HB and 61% in HS. HB subjects spent more time engaged in moderate to vigorous physical activity (60 ± 26 min·d vs 31 ± 13 min·d; P < 0.001).
Conclusions:
Significant differences observed in foot parameters, injury prevalence and general foot health between HB and HS suggest that footwear conditions may impact on foot structure and function and general foot health. HB children and adolescents spent more time engaged in moderate to vigorous physical activity and less time sedentary than HS children and adolescents.
Maintaining balance is vitally important in everyday life. Investigating the effects of individual foot muscle morphology on balance may provide insights into neuromuscular balance control mechanisms. This study aimed to examine the correlation between the morphology of foot muscles and balance performance during single-leg standing. Twenty-eight recreational runners were recruited in this study. An ultrasound device was used to measure the thickness and cross-sectional area of three intrinsic foot muscles (abductor hallucis, flexor digitorum brevis and quadratus plantae) and peroneus muscles. Participants were required to perform 30 seconds of single-leg standing for three trials on a force plate, which was used to record the center of pressure (COP). The standard deviation of the amplitude and ellipse area of the COP were calculated. In addition, stabilogram diffusion analysis (SDA) was performed on COP data. Pearson correlation coefficients were computed to examine the correlation between foot muscle morphology and traditional COP parameters as well as with SDA parameters. Our results showed that larger abductor hallucis correlated to smaller COP sway, while larger peroneus muscles correlated to larger COP sway during single-leg standing. Larger abductor hallucis also benefited open-loop dynamic stability, as well as supported a more efficient transfer from open-loop to closed loop control mechanisms. These results suggest that the morphology of foot muscles plays an important role in balance performance, and that strengthening the intrinsic foot muscles may be an effective way to improve balance.
Background:
Plantar heel pain is a common condition that reduces health-related quality of life. Recovery usually occurs within 12 months; however, up to 20% of people remain symptomatic beyond this time frame. The level of pain and function in this chronic heel pain group is not well described.
Objective:
To identify clinical and functional characteristics associated with chronic plantar heel pain compared with heel pain of recent onset.
Design:
Cross-sectional study.
Setting:
University research laboratory and private physiotherapy clinic.
Participants:
A total of 71 people with plantar heel pain for longer than 12 months and 64 people with plantar heel pain for less than 6 months were recruited from the general public.
Methods:
Functional characteristics of participants in both heel pain groups were assessed with a variety of clinical measures and the Foot Health Status Questionnaire. Clinical measures included body mass index, foot and ankle muscle strength using hand-held dynamometry, as well as ankle and first metatarsophalangeal joint range of motion. The Foot Health Status Questionnaire was used to collect self-reported measures of foot pain severity, foot function and physical activity.
Main outcome measurements:
Univariate analyses of variance were performed to detect differences between the 2 groups for each of the variables measured.
Results:
The chronic heel pain group exhibited reduced ankle dorsiflexor and toe flexor strength yet better self-reported foot function. There was no difference between groups for body mass index, ankle and first metatarsophalangeal joint range of motion, inversion strength, eversion strength, calf endurance, self-reported foot pain, and physical activity.
Conclusions:
Chronic plantar heel pain is associated with selective weakness of foot and ankle muscle groups but less affected foot function compared with heel pain of recent onset. Those with chronic symptoms may moderate or make adaptations to their daily activities, or simply accept their condition, enabling more effective coping. Strength deficits, although possibly a cause or consequence of chronic symptoms, suggest a need to include resistance exercise in the management of plantar heel pain.
Level of evidence:
To be determined.
We thank Damien Howell for the letter and the opportunity to
clarify some points from our article. We attempt to address each
of the issues raised in the letter.
Limited ankle dorsiflexion range of motion (ROM) is considered
a risk factor for plantar fasciitis, it is associated with chronic plantar
fasciitis, and it may also influence the Star Excursion Balance Test
(Irving et al., 2006; Gribble et al., 2012; Martin et al., 2014). We
measured ankle dorsiflexion ROM to verify the homogeneity
among groups, and to avoid bias of imbalance among groups in
baseline variables that could influence outcomes.
The three treatment groups performed stretching exercises,
which have an effect in ankle dorsiflexion (Porter et al., 2002).
The strengthening exercises performed in Foot Exercise Group
and Foot and Hip Exercise Group does not influence ankle dorsiflexion
ROM. Thus, the effects of three treatments groups on ankle dorsiflexion ROM might be the same.
The majority of the previous studies did not consider limit range
of motion as inclusion criteria for stretching exercises, and
observed beneficial effects on patients with plantar fasciitis
(Porter et al., 2002; DiGiovanni et al., 2003; Rompe et al., 2010).
Moreover, there is no evidence regarding that the indication for
stretching exercises should be only limited motion.
The plantar fasciitis diagnosis was performed by physicians,
who evaluated muscle, tendon, and nerve impairment, as well as
the plantar fascia with criteria well described in literature (McPoil
et al., 2008). We did not find studies that support that excessive
dorsiflexion of metatarsalphalangeal joint is associated with muscle
weakness in patients with plantar heel pain.
Weppler and Magnusson (2010) reviewed the literature and discussed
about factors that may be associated with increased muscle
extensibility through stretching, such as viscoelastic deformation,
plastic deformation of connective tissue, increase of sacomeres in
series, neuromuscular relaxation, and sensory theory. Sensory theory
suggests that increases in muscle extensibility observed after
stretching programs in healthy or unspecific disease subjects are
due to an alteration of sensory perception. Thus, this theory does
not correlate to improvement on pain and function of patients
with plantar fasciitis.
Short foot exercise (Jung et al., 2011a, 2011b; Mulligan and Cook,
2013) and towel curl exercise (Young et al., 2001) are the most common strengthening exercises for intrinsic foot muscles. However, as far as we are aware, there is no evidence that intrinsic foot muscles
strengthening with maximum foot plantar flexion has greater effect
on these muscles than other exercises (Soysa et al., 2012).
Study Design Controlled laboratory study. Background Plantar heel pain is one of the most common foot and ankle conditions seen in clinical practice and many individuals continue to have persisting or recurrent pain after treatment. Impaired foot plantar flexor muscle performance is a factor that may contribute to limited treatment success, but reliable methods to identify impairments in individuals with plantar heel pain are needed. In addition, foot orthoses are commonly used to treat this condition, but the implications of orthosis use on muscle performance have not been assessed. Objectives To assess ankle plantar flexor and toe flexor muscle performance of individuals with plantar heel pain using clinically-feasible measures and to examine the relationship between muscle performance and duration of foot orthosis use. Methods The rocker board plantar flexion test (RBPFT) and modified paper grip test for the great toe (mPGTGT) and lesser toes (mPGTLT) were used to assess foot plantar flexor muscle performance in 27 individuals with plantar heel pain and compared to 27 individuals without foot pain that were matched according to age, sex, and body mass. Pain ratings were obtained before and during testing, and self-reported duration of foot orthosis use was recorded. Results Compared to the control group, individuals with plantar heel pain demonstrated lower performance in the RBPFT (P = 0.001), the mPGTGT (P = 0.037) and the mPGTLT (P = 0.022). Longer duration of foot orthosis use was moderately correlated to lower performance on the RBPFT (r = -0.52, P = 0.02), the mPGTGT (r = -0.54, P = 0.01), and the mPGTLT (r = -0.43, P = 0.03). Conclusion Ankle plantar flexor and toe flexor muscle performance was impaired in individuals with plantar heel pain and associated with longer duration of self-reported foot orthosis use. J Orthop Sports Phys Ther, Epub 3 Jul 2016. doi:10.2519/jospt.2016.6482.