Article

Gait asymmetry in patients with limb length discrepancy

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0.15 BW)) (P=0.001). Peak plantar pressures were higher under the big toe in the long leg and the heel-off occurred faster. The push-off phase was initiated earlier in the short leg. The maximum isometric torque of the long limb was considerably greater (673 Nm vs. 239 Nm) (P=0.026). The results imply that the loading of the long limb is greater and the foot loading patterns shifted more to the forefoot in the long, limb to compensate walking disturbances caused by limb length discrepancies.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... [1,2]. For decades research has been published, defining the amount of LLI that needs to be treated; however, a clear consensus in the medical community has not been reached yet [1,[3][4][5][6][7][8]. In early work by Gross et al. in 1978, it was concluded that "there seems little indication for equalization of discrepancies less than 2 cm" [9], while treatment above this amount needs to be decided individually as relevant clinical and biomechanical data is missing. ...
... In early work by Gross et al. in 1978, it was concluded that "there seems little indication for equalization of discrepancies less than 2 cm" [9], while treatment above this amount needs to be decided individually as relevant clinical and biomechanical data is missing. Biomechanical studies have suggested that LLIs of 2 cm and more lead to relevant changes in the knee and ankle joints as well as to pelvic obliquity resulting in gait asymmetry [4,5,10]. Based on these findings some authors suggest to treat LLIs of more than 2 cm, while others recommend even earlier interventions [1-3, 6, 7]. ...
... So far, LLIs of 2 cm and greater are considered clinically relevant since they can lead to acute or chronic musculoskeletal changes and clinical symptoms [1,8]. However, there still exist some controversies in the literature regarding the exact amount of LLI that is considered to be clinically significant and which needs to be treated [1,[3][4][5][6]14]. Purpose of this study was to compare pelvic position and spinal posture in patients with LLI < 2 cm versus patients with LLIs > 2 cm during standing and while walking. ...
Article
Full-text available
Background Leg length inequalities are a frequent condition in every population. It is common clinical practice to consider LLIs of 2 cm and more as relevant and to treat those. However, the amount of LLIs that need treatment is not clearly defined in literature and the effect of real LLIs on the musculoskeletal system above and below 2 cm have not been studied biomechanically before. Methods By using surface topography, we evaluated 32 patients (10 females, 22 male) with real LLIs of ≥ 2 cm (mean: 2.72 cm; n = 10) and compared their pelvic position and spinal posture to patients with LLIs < 2 cm (mean: 1.24 cm; n = 22) while standing and walking. All patients were measured with a surface topography system during standing and while walking on a treadmill. To compare patient groups, we used Student t-tests for independent samples. Results Pelvic obliquity was significantly higher in patients with LLI ≥ 2 cm during the standing trial (p = 0.045) and during the midstance phase of the longer leg (p = 0.023) while walking. Further measurements did not reveal any significant differences (p = 0.06–0.706). Conclusions The results of our study suggest that relevant LLIs of ≥ 2 cm mostly affect pelvic obliquity and do not lead to significant alterations in the spinal posture during a standing trial. Additionally, we demonstrated that LLIs are better compensated when walking, showing almost no significant differences in pelvic and spinal posture between patients with LLIs smaller and greater than 2 cm. This study shows that LLIs ≥ 2 cm can still be compensated; however, we do not know if the compensation mechanisms may lead to long-term clinical pathologies.
... Moreover, the overuse of specific muscles in the case of muscle imbalances may result in compensatory muscle movements and changes in posture, which can lead to pain, overload, and increased injury risk of the locomotor apparatus [2]. Therefore, specific orthopaedic conditions are associated with muscle imbalances such as e.g. the cavovarus foot deformity [3], the patellofemoral pain syndrome [4], the medial tibial stress syndrome [5], lower back pain (LBP) [6], and leg length inequalities (LLIs) [7]. ...
... This was explained by compensatory changes of the hip, knee, and ankle joints during walking in an effort to shorten the longer limb and lengthen the shorter limb [9,14]. However, such compensation mechanisms can lead to muscle imbalances, which may cause further clinical symptoms, such as lower back pain (LBP), aseptic loosening of hip prostheses, increased risk of falling, and sports injuries [7,[16][17][18]. So far, there are no studies that have measured muscle activity in conjunction with kinematic parameters to further understand the association between kinematic and muscular compensation mechanisms of LLIs. ...
... By analyzing the effects of (simulated) LLIs on leg and back muscles, the effects could be compared in contrast to an isolated analysis of single back or leg muscles [7,[16][17][18]. They differ between the measured muscle groups, showing smaller effects of (simulated) LLIs on back muscles than on leg muscles. ...
Article
Muscle imbalances are a leading cause of musculoskeletal problems. One example are leg length inequalities (LLIs). This study aimed to analyze the effect of different (simulated) LLIs on back and leg muscles in combination with kinematic compensation mechanics. Therefore, 20 healthy volunteers were analyzed during walking with artificial LLIs (0-4 cm). The effect of different amounts of LLIs and significant differences to the reference condition without LLI were calculated of maximal joint angles, mean muscle activity, and its symmetry index. While walking, LLIs led to higher muscle activity and asymmetry of back muscles, by increased lumbar lateral flexion and pelvic obliquity. The rectus femoris showed higher values, independent of the amount of LLI, whereas the activity of the gastrocnemius on the shorter leg increased. The hip and knee flexion of the long leg increased significantly with increasing LLIs, like the knee extension and the ankle plantarflexion of the shorter leg. The described compensation mechanisms are explained by a dynamic lengthening of the short and shortening of the longer leg, which is associated with increased and asymmetrical muscle activity. Presenting this overview is important for a better understanding of the effects of LLIs to improve diagnostic and therapy in the future.
... Sachant que XD représente une valeur du côté droit et XG une valeur homologue du côté gauche. Plusieurs études ont utilisé cet indice afin d'analyser les différentes asymétries engendrées par les ILMI (Othman et al. 2019 ;Pereira 2008 ;Perttunen et al. 2004 ;White et al. 2004 ;Liu et al. 1998). ...
... Par le passé, Kaufman et al. (1996) avaient déjà signalé qu'une ILMI légère entraînait une démarche asymétrique, et ces auteurs avaient émis l'hypothèse que les personnes ayant une ILMI même légère utilisaient des mécanismes compensatoires pour allonger dynamiquement le membre court et le membre long, probablement pour minimiser le déplacement du centre de masse du corps. D'autres auteurs ont aussi indiqué que les ILMI légères affectaient la biomécanique de la démarche (Defrin et al. 2005 ;Perttunen et al. 2004 ;Seeley et al. 2010). Cependant, l'effet d'une ILMI légère sur la démarche n'a pas été démontré sans équivoque, comme l'ont récemment rappelé Resende et al. (2016a) et , bien que des études démontrent que même une ILMI ≤ 1,0 cm augmente le risque d'arthrose du genou (Harvey 2010), de scoliose (Specht et De 1991) et de lombalgie (Defrin et al. 2005). ...
... Il a été précédemment établi qu'une légère ILMI peut provoquer des troubles cinématiques de la marche et des douleurs Seeley et al. 2010 ;Defrin et al. 2005 ;Golightly et al. 2007 ;Perttunen et al. 2004). Cependant, les effets d'une légère ILMI sur la marche fait encore l'objet de débat, comme l'ont récemment souligné Resende et al. (2016a). ...
Thesis
La thèse présentée a pour objectif d’analyser les modifications cinématiques et affectives générées par les orthèses plantaires (OP) lors de la locomotion chez les sujets présentant une inégalité de la longueur des membres inférieurs (ILMI). L’ILMI est une affection courante due soit à des déformations anatomiques, soit à une déformation fonctionnelle. L’ILMI a été associée à plusieurs pathologies et douleurs au niveau des membres inférieurs et du bassin, et est souvent traitée par OP dans le domaine de la podologie. Cependant, il n’existe pas encore de réel consensus quant aux effets des OP sur la cinématique de la marche chez les sujets présentant une ILMI légère (≤ 3,0 cm). L’objectif général de cette thèse est de savoir si les OP peuvent être un traitement adapté pour les sujets présentant une légère ILMI. Une première étude nous a permis de mettre en avant une diminution significative des lombalgies chez les sujets présentant une ILMI légère sans effet significatif sur la symétrie articulaire après 3 semaines d’utilisation de semelles orthopédiques (SO). Ensuite, une revue systématique de la littérature a confirmé l’effet positif des OP sur les douleurs lombaires. Toutefois, les OP semblaient diminuer les déséquilibres cinématiques des sujets présentant une ILMI, seulement lorsque l’ILMI était modérée à sévère. Notre dernière étude révèle un effet immédiat des SO sur la cinématique et la douleur chez des sujets présentant une légère ILMI. Les SO semblent pouvoir améliorer la symétrie articulaire au niveau du bassin dans le plan frontal et de la cheville dans le plan sagittal, ainsi que la douleur des sujets présentant une légère ILMI. Ces trouvailles suggèrent que l’analyse cinématique peut être utile dans le domaine de la podologie.
... [9][10][11] One such misalignment is LLI. The presence of LLI has been associated with patellofemoral pain syndrome, 12 scoliosis, 13 gait asymmetry, 14,15,21 low back pain, 16 knee osteoarthritis, 17 iliotibial band friction syndrome, 18 and stress fractures. [19][20] Walsh et al 21 concluded using 3D motion analysis that artificially induced LLI caused compensatory mechanisms of the pelvis, knee, and ankle during gait. ...
... 14 In addition to asymmetrical gait kinematics, LLI has been associated asymmetrical kinetics. 15 Pertunen et al 15 found increased loading in the longer limb during gait among teenagers with moderate LLI (mean LLI=2.8cm). ...
... 14 In addition to asymmetrical gait kinematics, LLI has been associated asymmetrical kinetics. 15 Pertunen et al 15 found increased loading in the longer limb during gait among teenagers with moderate LLI (mean LLI=2.8cm). ...
Article
Background: Leg-length inequality (LLI) is a common condition that may contribute to various spinal, pelvic, and lower extremity dysfunctions. Iliac crest height difference (ICHD) has been demonstrated to be a good estimate for LLI and may be a useful measure for identifying individuals who are at risk for injury. Purpose: To investigate the relationship between ICHD and other running-related variables with running injury. Methods: An observational retrospective case-control design was used. Data were collected via questionnaire and physical examination from a purposive sample of 100 runners and were analyzed using chi-squared tests of independence. Results: The prevalence of ICHD ≥ 5mm reported by subjects via questionnaire was ∼40%. There was no difference in report of injury between subjects with ICHD >5mm and those with ICHD <5mm (χ2 = 0.02, p = 0.88); however, lifetime history of injury (χ2 = 15.68, p = 0.00) and the number of running events participated (χ2 = 3.09, p = 0.04) were significant factors associated with injury; although not significant, there was a trend towards relationship with gender (χ2 = 3.2, = 0.07). Conclusion: Small ICHD is not associated with running injury among recreational runners. There appears to be an increased risk of running injury among runners who participate in more than one running event annually and those that have had a past history of running injury. Also, males may be at slightly greater risk of sustaining a running injury compared to females. Level of evidence: Therapy, level 3b.
... In humans, limb length discrepancies lead to increased weight bearing with the shorter limb and increased pushing off (propulsion) with the longer limb [20,21]. In horses, manipulation of limb length is for example of interest for correcting force asymmetries in the presence of asymmetrical feet [22], which may be relevant for rehabilitation regimens in horses with differently shaped hooves. ...
... This study has investigated the application of an artificial lengthening of a pelvic limb-a simple mechanical change-termed an orthotic lift and its immediate influence on pelvic as well as head and withers movement asymmetry parameters. The most consistent changes were measured for pelvic movement asymmetry and these are in agreement with the effects observed in humans [20,21]. Both head and withers movement asymmetry were also affected indicating consequences expanding across the whole trunk and head-neck segment. ...
... Whether or not the prediction of force asymmetry from upper body kinematics, as found previously [4,5], works reliably in the presence of limb length discrepancies ultimately needs clarification by means of concurrent measurement of ground reaction force. Studies in human subjects with natural and artificial limb length discrepancies provide initial support for the ability to predict force asymmetry from kinematic asymmetries even under these circumstances: there the shorter limb experiences a higher peak vertical force and the longer limb provides more propulsion [20,21]. This would also be predicted from our study: with a left-sided orthotic lift (longer LH limb) a horse appears left-asymmetrical in terms of PDmin, i.e. shows a pattern commonly seen in a LH lame horse, which produces more force with the Table 2. ...
Article
Full-text available
In trotting horses, movement asymmetry is associated with ground reaction force asymmetry. In humans, limb length differences influence contralateral force production. Here we investigate whether horses, in immediate reaction to limb length changes, show movement asymmetry adaptations consistent with reported force differences. Aim of this study was to quantify pelvic and compensatory head and withers movement asymmetry as a function of limb length changes after application of orthotic lifts. In this experimental study movement asymmetry of eleven trotting horses was calculated from vertical displacement of poll, withers, sacrum and left and right tuber coxae with inertial sensors. Horses were assessed in-hand under 5 conditions (all with hind limb boots): without orthotic lifts, and with a 15mm or 30mm orthotic lift applied to the left hind or right hind. A linear mixed model investigated the influence of orthotic lift condition (P<0.05, pairwise posthoc Bonferroni correction). Pelvic movement asymmetry showed increased pelvic downward movement during stance of the shorter limb and increased pelvic upward movement during and after stance of the longer limb (P<0.001) with asymmetry changes of 3-7mm (4-10mm) for 15mm (30mm) lifts. Hip hike (tuber coxae movement asymmetry) was unaffected (P = 0.348). Head and withers movement asymmetry were affected less consistently (2 of 3 respectively 1 of 3 head or withers parameters). The small sample size of the study reduced generalizability, no direct force measurements were conducted and only immediate effects of orthotic lifts were assessed with no re-assessments days or weeks after. Conclusions about mechanical consequences (weight bearing, pushoff) are based on published movement-force associations. Pelvic movement asymmetry with an artificial change in limb length through application of an orthotic lift indicates increased weight support with the shorter limb and increased pushoff with the longer limb. This may be of relevance for the management of horses with different hoof shapes between contralateral limbs, for example some chronically lame horse.
... Impairment between two legs caused by leg length inequality or also known as leg length discrepancy (LLD) provoke mechanical and functional changes in terms of gait pattern and posture alteration, changes in joint moments and power as well as unbalance loading transfer within each segments [1]- [3]. Small magnitude of LLD, commonly classified as "mild LLD", also caused the repetitive loading on specific joint and segment [4]. ...
... There is such evidence that an abnormal transmitting load on both limbs may predispose to a degenerative joint disease likewise a knee, hip or lumbar arthritis [7]. A development of superolateral hip arthritis was found on the longer side [3], increase stress joint moment on the acetabulum cup of hip on the short limb [1], increase of the ground reaction forces on the long leg [8] and decrease in push-off force in long leg while increase of the weight acceptance rate on the shorter limb [9]. In terms of anatomical changes, the pelvis tilt and obliquity were being widely discussed [5], [10]- [14]. ...
... The additional effect of LLD's magnitudes with the induced loading (between short and long limb) on lower limb joints remains unclear. Numerous kinematics studies of LLD have emphasised the effect of congenital LLD [3], [16] and shoe lift [17]. Along with time, the congenital LLD had better accommodating motion pattern and joint loading as compared to an individual who is late-onset with the LLD case, like in a patient with a joint disease such as osteoarthritis. ...
Article
Full-text available
Purpose: The aim of this study was to examine the joint contact forces (JCF) between each limb as the LLD magnitude increases during walking activity. Methods: Eighteen male healthy subjects volunteered to participate in the experiment. Walking gait analysis was conducted with eight different levels of insole to simulate the LLD, starting from 0 cm until 4.0 cm with 0.5 cm increment. Qualisys Track Manager System and C-motion Visual 3D biomechanical tools were used to analyse the results. Four joints (ankle, knee, hip, and pelvis) of lower limb of two legs were investigated. The increment of insoles was placed on the right leg to represent the long leg. Results: The results suggest that the mean contact forces for all joints in the short leg were increased as the increment level increased. On the contrary, the mean contact forces in the long leg decreased when the LLD level increased. Among these four joints, JCF in hip shows a positive increment based on the ASI value. Means that hip shows the most affected joint as the LLD level increase. Conclusions: The result obtained in this study might help clinicians treat patients with a structural LLD for treatment plan including surgical intervention.
... The question to what extent a specific conformational asymmetry will lead to movement asymmetries is highly relevant in the context of normal variation. In humans, specific focus has been put on dif-ferences between the lengths of the left and right limbs (Perttunen et al, 2004;White et al, 2004) in relation to differences in force distribution during foot contact. This relationship may also be of interest in horses, for example when presented with a horse with different hoof shapes between contralateral limbs (Wiggers et al, 2015) or when applying corrective farriery involving wedges (Ross, 2011). ...
... This relationship may also be of interest in horses, for example when presented with a horse with different hoof shapes between contralateral limbs (Wiggers et al, 2015) or when applying corrective farriery involving wedges (Ross, 2011). The fact that, in humans, limb length differences are associated with distinct differences in weight bearing and propulsion (Perttunen et al, 2004;White et al, 2004) renders this conformational difference particularly interesting: changes in weight bearing and propulsion can also be associated with head and pelvic movement asymmetry in the horse Bell et al, 2016) (this concept will be visited in more detail later). In horses, artificially induced limb length differences between contralateral hind limbs can lead to pelvic movement asymmetries of 3-7 mm for 15 mm limb length difference and up to 10 mm for a more extreme 23 mm limb length difference. ...
Article
Quantitative gait analysis in the lame horse has gained in popularity, likely related to the potential to remove bias from the clinical decision-making process. Its implementation into clinical practice is, however, not without challenges. This review visits some of the challenges related to the use of thresholds and guideline values in the context of clinical decision making, as well as when applied to scientific studies based on relevant published studies: issues such as ‘normal day-to-day variation’, conformational asymmetry and the often limited number of parameters that are being quantified. Emphasis is put on outlining the basic underlying principles relating to head nod and hip hike, which are explained in the context of Newtonian mechanics associating reduced vertical acceleration of the upper body to reduced force production with the limb that is in contact with the ground during that time period. Further to quantifying what can be seen ‘by eye’, the review also visits phenomena such as asymmetries in weight bearing or pushoff and compensatory mechanisms, with emphasis on measurement of withers movement and thoughts about multilimb lameness. The review concludes with thoughts about additional parameters such as limb movement and movement of the thoraco-lumbo-sacral area, which may provide additional insights into lameness and poor performance but are at current less frequently included into clinical gait analysis in the horse.
... (1,2). For decades research has been published, de ning the amount of LLI that needs to be treated; however, a clear consensus in the medical community has not been reached yet (1,(3)(4)(5)(6)(7)(8). In early work by Gross et al. in 1978, it was concluded that "there seems little indication for equalization of discrepancies less than 2 cm" (9), while treatment above this amount needs to be decided individually as relevant clinical and biomechanical data is missing. ...
... In early work by Gross et al. in 1978, it was concluded that "there seems little indication for equalization of discrepancies less than 2 cm" (9), while treatment above this amount needs to be decided individually as relevant clinical and biomechanical data is missing. Biomechanical studies have suggested that LLIs of 2cm and more lead to relevant changes in the knee and ankle joints as well as to pelvic obliquity resulting in gait asymmetry (4,5,10). Based on these ndings some authors suggest to treat LLIs of more than 2 cm, while others recommend even earlier interventions (1-3, 6, 7). ...
Preprint
Full-text available
Background Leg length inequalities (LLIs) are a frequent condition in every population. It is common clinical practice to consider LLIs of 2cm and more as relevant and to treat those. However, the amount of LLIs that need treatment is not clearly defined in literature and the effect of real LLIs on the musculoskeletal system above and below 2cm have not been studied biomechanically before.Research question: Are the spine and pelvis affected differently in patients with LLIs <2cm and ≥2cm.Methods By using surface topography, we evaluated 32 patients (10 females, 22 male) with real LLIs of ≥2cm (mean: 2.72cm; n=10) and compared their pelvic position and spinal posture to patients with LLIs <2cm (mean: 1.24cm; n=22) while standing and walking. All patients were measured with a surface topography system during standing and while walking on a treadmill. To compare patient groups, we used Student t-tests for independent samples.ResultsPelvic obliquity was significantly higher in patients with LLI ≥2cm during the standing trial (p=0.045) and during the midstance phase of the longer leg (p=0.023) while walking. Further measurements did not reveal any significant differences (p=0.06-0.706).Conclusion The results of our study suggest that relevant LLIs of ≥2cm mostly affect pelvic obliquity and do not lead to significant alterations in the spinal posture during a standing trial. Additionally, we demonstrated that LLIs are better compensated when walking, showing almost no significant differences in pelvic and spinal posture between patients with LLIs smaller and greater than 2 cm. This study shows that LLIs ≥2cm can still be compensated; however, we do not know if the compensation mechanisms may lead to long-term clinical pathologies.
... Moreover, there was a significant reduction in pain with the OI (with no betweengroup differences). The kinematic results support the findings of a number of studies that showed that even mild LLD can alter the kinematics of gait and cause pain (Perttunen et al., 2004;Defrin et al., 2005;Golightly et al., 2007;Seeley et al., 2010;Khamis and Carmeli, 2018). The results of this study add to this body of knowledge by showing that even LLD < 1 cm can alter symmetry and cause pain, and that both symmetry and pain can be improved with OI. ...
... Finally, it would be interesting to highlight other aspects of motion analysis that could complete and explain some of our results. Indeed, with a kinetic approach, Aiona et al. (2015) and Song et al. (1997) put forward a more important mechanical work of the long leg, therefore possibly a more important articular, muscular, and tendinous work, which was confirmed by Perttunen et al. (2004). In future studies, it would be interesting to supplement the kinematic data with kinetic variables coupled with electromyographic analysis to refine the understanding of the effect of OI on changes in the biomechanics of locomotion. ...
Article
Full-text available
Background: Mild leg length discrepancy can lead to musculoskeletal disorders; however, the magnitude starting from which leg length discrepancy alters the biomechanics of gait or benefits from treatment interventions is not clear. Research question: The aim of the current study was to examine the immediate effects of orthotic insoles on gait symmetry and pain on mild leg length discrepancy according to two groups of the leg length discrepancy (i.e., LLD ≤ 1 cm vs. LLD > 1 cm). Methods: Forty-six adults with mild leg length discrepancy were retrospectively included and classified into two groups (GLLD≤1cm or GLLD>1cm). All subjects underwent routine 3D gait analysis with and without orthotic insoles. The symmetry index was calculated to assess changes in gait symmetry between the right and left limbs. Pain was rated without (in standing) and with the orthotic insoles (after 30 min of use) on a visual analog scale. Results: There was a significant improvement in the symmetry index of the pelvis in the frontal plane (p = 0.001) and the ankle in the sagittal plane (p = 0.010) in the stance with the orthotic insoles independent from the group. Pain reduced significantly with the orthotic insoles independently from the group (p < 0.001). Significance: Orthotic insoles significantly improved gait symmetry in the pelvis in the frontal plane and the ankle in the sagittal plane, as well as pain in all subjects (both LLD ≤ 1 cm and LLD > 1 cm) suggesting that it may be appropriate to treat even mild leg length discrepancy.
... Moreover, there was a significant reduction in pain with the OI (with no betweengroup differences). The kinematic results support the findings of a number of studies that showed that even mild LLD can alter the kinematics of gait and cause pain (Perttunen et al., 2004;Defrin et al., 2005;Golightly et al., 2007;Seeley et al., 2010;Khamis and Carmeli, 2018). The results of this study add to this body of knowledge by showing that even LLD < 1 cm can alter symmetry and cause pain, and that both symmetry and pain can be improved with OI. ...
... Finally, it would be interesting to highlight other aspects of motion analysis that could complete and explain some of our results. Indeed, with a kinetic approach, Aiona et al. (2015) and Song et al. (1997) put forward a more important mechanical work of the long leg, therefore possibly a more important articular, muscular, and tendinous work, which was confirmed by Perttunen et al. (2004). In future studies, it would be interesting to supplement the kinematic data with kinetic variables coupled with electromyographic analysis to refine the understanding of the effect of OI on changes in the biomechanics of locomotion. ...
Book
Full-text available
Running technique has been analyzed since antiquity, and yet the study of gait biomechanics is continually developing and unearthing new insights. This is undoubtedly linked to the great variety of skills required in the running and race walking events, despite their apparent simplicity: a fast but fair sprint start, safe and effective hurdle clearances, negotiation of the tight bends in indoor racing, and coping with changes in gradient in road and cross country running are just a few examples. Increasingly, coaches and governing bodies are looking to sports science to help improve their best athletes and raise participation rates in recreational sport, and need a comprehensive resource on technique, performance and training. Regardless of their standard, competitive athletes strive to improve performance and reduce the risk of injury, and biomechanists are ideally placed to support athletes and coaches in this universal sport.
... Bien que la symétrie ait été largement étudiée dans le domaine de la marche (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004) ou du cyclisme (Daly et Cavanagh, 1976 ;Smak et al., 1999), peu d'études se sont intéressées à la symétrie de propulsion en FRM. En effet, il semblerait qu'une asymétrie notamment due aux différences bilatérales anthropométriques existe lors la marche, et que plus les écarts sont importants, plus l'asymétrie constatée est grande (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004). ...
... Bien que la symétrie ait été largement étudiée dans le domaine de la marche (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004) ou du cyclisme (Daly et Cavanagh, 1976 ;Smak et al., 1999), peu d'études se sont intéressées à la symétrie de propulsion en FRM. En effet, il semblerait qu'une asymétrie notamment due aux différences bilatérales anthropométriques existe lors la marche, et que plus les écarts sont importants, plus l'asymétrie constatée est grande (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004). Ainsi, il se pourrait que les différences anthropométriques au niveau des membres supérieurs soient à l'origine d'une asymétrie de la propulsion. ...
Article
Introduction On distingue deux principaux modes de propulsion en fauteuil roulant manuel (FRM) : synchrone (Syn) et asynchrone (Asy), qui ont largement été étudiés sur tapis roulant ou ergomètre à rouleaux [1]. Cependant, en Asy les mouvements latéraux du FRM (steering) sont neutralisés et ses conséquences n’ont jamais été étudiées. L’objectif est d’analyser l’influence des modes Syn et Asy lors du démarrage et de la propulsion sur la symétrie et sur la stabilité du tronc en situation écologique. Matériels et méthode Un sujet (homme, amputé fémoral, 33 ans, 1,69 m, 80 kg) a effectué 3 poussées selon 4 passages (démarrage & vitesse stabilisée, Syn & Asy). Le fauteuil roulant ergometre de terrain [2] a permis de recueillir les variations du centre de pression (CP). Les amplitudes du tronc et l’indice de symétrie (ISI) [3] sont calculés à partir des données recueillies avec un système Vicon. Résultats Les paramètres recueillis sont présentés dans le Tableau 1 (moyennes ± écart-types). Conclusion Lors du mode Asy, la symétrie de propulsion semble inférieure à la propulsion Syn de 15 % pour le démarrage et de 16 % pour la propulsion, et le sujet semble plus instable, avec des mouvements du tronc plus importants. Ces résultats préliminaires pourraient expliquer l’utilisation privilégiée de la propulsion Syn dans les activités sportives par les blessés médullaires avec une instabilité du tronc. Il semble intéressant de poursuivre cette étude auprès d’un échantillon plus conséquent afin de valider nos hypothèses.
... Bien que la symétrie ait été largement étudiée dans le domaine de la marche (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004) ou du cyclisme (Daly et Cavanagh, 1976 ;Smak et al., 1999), peu d'études se sont intéressées à la symétrie de propulsion en FRM. En effet, il semblerait qu'une asymétrie notamment due aux différences bilatérales anthropométriques existe lors la marche, et que plus les écarts sont importants, plus l'asymétrie constatée est grande (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004). ...
... Bien que la symétrie ait été largement étudiée dans le domaine de la marche (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004) ou du cyclisme (Daly et Cavanagh, 1976 ;Smak et al., 1999), peu d'études se sont intéressées à la symétrie de propulsion en FRM. En effet, il semblerait qu'une asymétrie notamment due aux différences bilatérales anthropométriques existe lors la marche, et que plus les écarts sont importants, plus l'asymétrie constatée est grande (Kaufman et al., 1996 ;Bhave et al., 1999 ;Perttunen et al., 2004). Ainsi, il se pourrait que les différences anthropométriques au niveau des membres supérieurs soient à l'origine d'une asymétrie de la propulsion. ...
Thesis
Le handibasket est pratiqué par des sportifs en Fauteuil Roulant Manuel (FRM) dont la déficience a un impact direct sur leurs capacités physiques et leurs performances. L’évaluation des capacités physiques des sportifs est un élément essentiel du suivi de leur entraînement, leur permettant de maintenir voire améliorer leurs performances et de limiter les risques de blessures. Si nous savons que les athlètes utilisent principalement deux modes de propulsion (Synchrone - Syn - et Asynchrone - Asy), peu d’études ont porté sur leur analyse comparée chez des handisportifs et la majorité d’entre elles ont été réalisées en laboratoire, avec des sujets sains. Or, nous disposons de très peu d’études comparées laboratoire - terrain et valides - handisportifs permettant d’affirmer que les tests effectués en laboratoire, de surcroit sur des sujets sains, sont représentatifs de la réalité de la pratique handisport sur le terrain. Ainsi, cette thèse a pour objectif d’étudier les différentes techniques de propulsion en FRM chez des handisportifs dans l’optique de contribuer à améliorer la performance et de réduire les facteurs de risque de blessures liés aux contraintes de la discipline. Pour cela, la première étape a consisté à comparer les réponses physiologiques et biomécaniques de la propulsion Asy entre le tapis roulant et le terrain. Nous avons montré que l’analyse de la propulsion Asy n’est pas préconisée sur un tapis roulant car il ne reproduit pas fidèlement les conditions de terrain, notamment à cause des mouvements latéraux du FRM (steering) plus important pour ce mode de propulsion, qui sont neutralisés par le maintien du FRM sur le tapis roulant. Nous avons montré que la dépense énergétique est alors plus importante et que certains paramètres biomécaniques sont modifiés par rapport à une propulsion sur le tapis roulant où le steering est neutralisé. Nous émettons l’hypothèse qu’en fonction de ses capacités résiduelles, l’athlète utilise de manière accrue ses muscles du tronc pour assurer sa stabilité posturale lors du mode Asy. Ensuite, une comparaison des deux modes de propulsion a été réalisée sur le terrain lors de trois types de tests : premièrement, lors de tests sous-maximaux (session de 4 min à 8 km.h-1), deuxièmement, lors de tests d’endurance progressif type Vameval permettant de mesurer la capacité aérobie des athlètes, et enfin lors de sprints permettant de mesurer la capacité anaérobie des athlètes. Les résultats montrent que la propulsion Asy augmente les paramètres temporels (temps de recouvrement et temps de cycle) ainsi que l’efficacité de la propulsion alors que la propulsion Syn semble être plus performante et davantage à risque de développer des blessures. Enfin, à l’aide d’un ergomètre instrumenté FRET couplé à un système d’analyse du mouvement, nous avons quantifié l’effet de ces deux modes de propulsion sur la symétrie et les mouvements du tronc. Pour cela, nous avons choisi d’analyser l’influence des modes de propulsion Syn et Asy lors du démarrage et lors de la propulsion à vitesse stabilisée, chez des sujets sportifs. Les résultats montrent que la propulsion Asy induit plus d’asymétrie par rapport à la propulsion Syn. Les mouvements médio-latéraux du tronc associés aux amplitudes de déplacement du centre de gravité supérieure dans le plan médio-latéral ainsi qu’aux mouvements de steering plus importants observés lors du mode Asy suggèrent une plus grande instabilité posturale et une activité musculaire accrue des muscles du tronc. Ainsi, au regard de ces résultats, en fonction des capacités physiques de l’athlète, des phases de jeux et de la période d’entrainement, il serait plus recommandé de choisir l’un ou l’autre des modes de propulsion. L’amélioration des performances lors de la propulsion en ligne droite et sans ballon, nous semble passer par l’utilisation de la propulsion Syn alors que la propulsion Asy serait à préconiser pour la prévention des blessures et la récupération.
... In addition to asymmetrical gait kinematics, LLI has been associated with asymmetrical kinetics. 4,5 Perttunen et al 5 found increases in stance time (p ≤ 0.001), ground reaction forces (p < 0.027), and plantar pressures (p < 0.037) during gait in the longer limb among teenagers with moderate LLI (mean LLI =2.8cm); larger disparities in ground reaction forces were found with increased walking speed (p = 0.001). In contrast, White et al 6 found trends towards increased ground reaction forces in the shorter limb among individuals with structural and artificially induced LLI ranging between 1-3cm. ...
... Previous research suggests the discrepancy threshold at which LLI begins to significantly alter gait symmetry and negatively impact gait economy is between 2-3cm. 4,5,19 Given this information, it is likely that the human body is able to effectively compensate for small LLI (i.e. < 1cm) while running, therefore correction appears to be unnecessary. ...
Article
Background: Leg-length inequality (LLI) is a musculoskeletal condition where one lower extremity is longer than the other. There is conflicting evidence on the relevance of LLI and conservative treatment options. Iliac crest height difference (ICHD) is a good estimate of LLI. Objective: To observe changes in pain and performance among recreational runners with running-induced lower extremity pain who received ICHD correction. Methods: A 12-week case series with multiple baseline and intervention (A-B-A-B) phases was used to observe the effects of ICHD correction on pain and performance among three symptomatic recreational runners. Primary outcome measures included the Lower Extremity Functional Scale (LEFS), the Visual Analog Scale -Worst Pain (VAS-W), symptom-free running distance, and average running speed. A standardized procedure for fabricating an in-shoe shim was utilized for ICHD correction. Results: There were no clinically important differences in functional capacity for any subject between any phases. Also, two subjects demonstrated trends towards increased pain over the 12-week experimental period, whereas one subject demonstrated a decrease. One subject demonstrated a statistically significant increase in running distance during intervention phases, but the others demonstrated reductions. All subjects demonstrated trends towards increased running speed, but none were statistically significant. Conclusion: The correction of small ICHD < 9mm did not improve pain or performance among recreational runners. Individuals with small ICHD may be able to effectively compensate for lower extremity asymmetries; therefore, correction seems to be unnecessary and potentially harmful in short-term. Level of evidence: Therapy, level 4.
... The bad posture of body, kept for a long while, may cause part of the body deviating from an original alignment of body. And to compensate the deviation, other parts of body subsequently move; this will promote the postural deformation resulting in the unbalanced posture of body (Perttunen et al., 2004). The results obtained from the analyses of standing postures of the subjects in the group of SG participated in this study showed the observations of unbalanced postures which were comprised of the following: unbalanced height of pelvis, unbalanced central position of left knee, unbalanced left external auditory meatus, and unbalanced left and right angles of pelvis. ...
Article
Full-text available
This study intended to analyze the characteristics of standing posture and factors related to sarcopenia of elderly women in Korea to provide basic data for the development of rehabilitation programs designed to prevent and control of the sarcopenia of elderly women. A total of 194 elderly women, aged over 65 years old, living in Gyeonggi-do, were selected to diagnose the presence of sarcopenia through bioelectrical impedance analysis (BIA) and muscle function test (gait speed and grip strength). The subjects were then distinguished into normal group (NG=92), presarcopenia group (PG=86), and sarcopenia group (SG=16); the standing posture of elderly women was captured with the three-dimensional (3D) imaging technique (PA200), and an analysis of variance (ANOVA) was carried out for the collected data through IBM SPSS Statistics ver. 23.0. The frontal measurements of standing posture, the pelvic level, R-patella center, and L-patella center, appeared with significant differences from each other whereas, the side measurements of standing posture, the R-earhole position, L-earhole position, R-shoulder position, L-shoulder position, R-pelvic angle, L-pelvic angle, R-knee position, and L-knee position, were also found with significant differences from each other. As a consequence, an intervention to be focusing on obese control was found necessary to prevent or to delay the presence of sarcopenia of elderly women. The positional displacement found from head, knee, and pelvis also necessitates the introduction of rehabilitation program customized for elderly women suffering the sarcopenia.
... Perttunen y cols. encontraron un aumento de la carga en el miembro largo en pacientes con AMI 19 . Song y cols. ...
Article
Full-text available
Introduction: The presence of compensations in patients with limb length inequality (LLI) is still an issue of debate. The present study compared diff erences in the static position and in the plantar pressure distribution during standing of both feet of patients with LLI. Patients and methods: The study included patients with LLI (diagnosed with full limb x-rays) who went to a foot offi ce by diff erent reasons. The foot posture index (FPI) and the percentage of plantar pressure distribution between the left and right feet during static standing were measured in both feet. Diff erences in the FPI and plantar pressure distribution of the long and short limbs were analyzed. Results: A total of 19 subjects were included in the study. No diff erences were found in the FPI neither the plantar pressure distribution in standing static between the short and long limbs of patients with LLI. Conclusion: Data of the present study do not support the idea of compensation patterns in LLI patients in which foot position or plantar pressure distribution between the short and long limbs in static position are changed. However, singular characteristics of the sample of the study (patients with pain or ailments in
... However, an orthopaedic boot elevates one foot and thus creates an artificial leg length discrepancy (LLD) [1]. LLDs have previously been shown to cause gait asymmetries [4], which in turn may lead to musculoskeletal problems of the back and lower limbs [5]. Although some degree of asymmetry is normal during gait [6], it is possible that the LLD amplifies the asymmetries and contributes to abnormal loading or injury [5]. ...
Article
Background: Orthopaedic walking boots are commonly prescribed following injury and surgery. The boot creates a leg length discrepancy which is thought to affect limb symmetry and gait mechanics. This study aimed to examine the effects of a corrective heel lift for the contralateral limb on the mechanics and symmetry of walking with an orthopaedic walking boot. Research question: Does a corrective heel lift reduce biomechanical alterations and asymmetries caused by an orthopaedic boot during gait? Methods: Healthy males (n=17) walked with normal shoes (Shod), an orthopaedic boot (Boot), and a corrective heel lift on the contralateral limb to the boot (Lift). A 10-camera motion capture system (Vicon, 100Hz) and four force platforms (AMTI, 1000 Hz) recorded lower extremity biomechanics. Pairwise statistics tested for differences in hip and knee kinematics and kinetics, and a symmetry index quantified limb symmetry. Findings: The Boot affected the sagittal and frontal plane hip mechanics and transverse plane knee mechanics (p<0.05), and increased the asymmetry compared to the Shod condition. The Lift improved the symmetry of some measures but increased the frontal plane hip asymmetry compared to the Boot. However, introducing the Lift did not change all kinematic variables affected by the boot. Significance: The Lift reduced some of the asymmetries introduced by the Boot, but also introduced new asymmetry in the hip frontal plane motion. The leg length discrepancy caused by the boot is probably not the only cause of altered gait mechanics. Prescribing a heel lift to a patient with an orthopaedic walking boot should be based on the individual patient's needs.
... Where , is sequence. When SI <10%, the symmetry was considered acceptable (Perttunen et al., 2004). In this study, results of DTW and SI were compared. ...
Article
Full-text available
The purpose of this study was to investigate the effectiveness of dynamic time warping (DTW) in gait research. Participants in this study were consist of 10 males and 10 females. Equipment used for collecting the gait data of participants in this study was three-dimensional (3D) motion analysis system consisted of 8 infrared CCD cameras operated with a sampling frequency of 120 frames/sec. DTW program used in this study was made using the MATLAB and the normal operation of the DTW program was verified by comparison of result manually calculated and output by the DTW program. Flexion angle of the knee joint of both feet obtained by 3D motion analysis system was analyzed by the DTW program and symmetry index (SI) equation. Statistical analysis of the values obtained by DTW was performed by one-sample t-test in confidence interval (CI) 99%, 95%, 90%, 85%, and 80% each using the SPSS. The subjects' left and right legs were compared 20 times, and other steps of the same foot were compared 20 times. In this study, DTW showed different results from SI which is generally used to test the similarity of gait. Compared to that of DTW, the threshold figure for similarity evaluation in SI, 10%, is considered too large/high. When the CI threshold figure of 95% was adopted in statistical analysis, DTW demonstrated a lower rate of judging two sequences as similar even in the case of normal gait. This study suggests that DTW can be used for the similarity test of gait research.
... Beside the mediolateral direction, the peak of normal GRF was also altered by the cross-slope condition, which showed a relatively smaller MaxFz2 for the downslope limb compared with the upslope limb and level limb (Fig. 3d). This asymmetric gait pattern is used to preserve lateral balance and sustain forward locomotion, which is similar to the performance of patients with leg length discrepancy, who also showed different vertical GRFs between limbs during gait [16,17]. ...
Article
Background: Walking on railroad ballast is a unique challenge for railroad workers and contributes to a large number of falls and slips. However, the characteristics of ground reaction force (GRF) when walking on ballast combined with a cross-slope condition are poorly understood. Research question: How does the magnitude and temporal distribution of GRF change during walking on railroad ballast combined with a cross-slope condition? Methods: Eight experienced railroad workers walked with their self-selected speed on three surfaces (mainline ballast, walking ballast and no ballast) in both a level and cross-slope (7°) condition. The magnitude and time of occurrence of selected key features of the GRF were extracted from the force plate. A two-factor repeated measures ANOVA was used to determine the effect of surface and cross-slope condition. Results: The minimum anteroposterior GRF and the first peak of the normal GRF occurred earlier on mainline ballast and walking ballast than no ballast. The maximum anteroposterior GRF was smaller, but the first peak of the normal GRF was larger on walking ballast compared with no ballast. Additionally, the asymmetrically mediolateral GRFs were observed between upslope limb and downslope limb in the cross-slope condition, which were also significantly different from the level condition. Significance: Ballast combined with a cross-slope condition posed a higher requirement for dynamic control to prevent downslope slippage and body instability, which could increase the fall risk for railroad workers. Future studies should investigate interventions to improve dynamic balance and reduce foot slippage on ballast.
... In this chapter, the mean joint angle and joint symmetry in 8 phases of the gait cycle in three spatial planes, vertical ground reaction force, time in stance and leg length discrepancy in both legs were measured and compared to healthy controls. Increased length of the operated leg has been reported in patients following routine joint replacement surgeries (Perttunen et al. 2004;Lang et al. 2012;Clark et al. 2006) and has been associated with complications such as nerve palsy, lower back pain, and abnormal gait (Clark et al. 2006). It has been demonstrated that mechanical load and isometric torque placed on the longer limb are significantly greater than that of the shorter limb (Gurney 2002). ...
Conference Paper
Distal femoral and proximal tibial joint-sparing bone tumour implants allow to preserve the knee, in limb salvage surgery. The aim of this thesis was to compare implant survival, functional outcomes, acceptance, proprioception and gait in patients with knee sparing implants and conventional knee sacrificing implants. Using FEA, a distal femoral implant and cadaver bone were modelled and parametrised to find the design that improves implant fixation. A survivorship study of 104 consecutive patients following knee sparing surgery (mean follow-up 36.1 ± 11.0 months) found an implant survival rate of 78% and this is comparable to the reported survival for joint sacrificing prostheses. Younger patients showed improved implant survival compared to older individuals. Plate fracture was not observed and aseptic loosening was the main reason for revision. Radiographic analysis indicated that implantation accuracy increased implant survival. Patient questionnaires showed that patients with knee sparing implants had more normal functional outcome and acceptance compared with patients with knee sacrificing implants. However, proprioception (joint position sense) was reduced in these patients. Using optoelectronic gait analysis system, hip, knee and ankle joint angle in 19 patients and 3 healthy subjects were measured. Ground reaction force and time in stance were also investigated. Joint symmetry in the joint sacrificing group was improved compared to the joint-sparing group, however overall, the joint-sparing tibial group demonstrated a more normal gait pattern. FEA results indicated that lower resection levels, reduced plate thickness and implant materials with lower modulus, decreased the stresses in the bone adjacent to the implant while loaded the bone more to reduce risk of stress shielding. To conclude, knee sparing endoprostheses provide a reliable alternative to knee sacrificing implants in limb reconstruction in selected patients. However, the current design of joint-sparing implants can be optimised to potentially improve bone remodelling and implant fixation.
... Theoretically, reduction of push-off impulse/work (namely propulsive impulse or work) from one leg leads to gait temporal-spatial asymmetry [27], [32]. Many experimental studies on pathological gait have shown evidence to support this mechanism [32], [33], including cases of amputees walking with energetically passive prostheses due to inadequate push-off impulse from prosthetic limb [28], [29]. However, when walking with robotic prostheses, which are capable of providing positive work at prosthetic joints for increased pushoff force, gait asymmetry persists [19]. ...
Article
Full-text available
With advances in robotic prostheses, researchers attempt to improve amputee’s gait performance (e.g., gait symmetry) beyond restoring normative knee kinematics/kinetics. Yet, little is known about how the prosthesis mechanics/control influence wearer-prosthesis’ gait performance, such as gait symmetry, stability, etc. This study aimed to investigate the influence of robotic transfemoral prosthesis mechanics on human wearers’ gait symmetry. The investigation was enabled by our previously designed reinforcement learning (RL) supplementary control, which simultaneously tuned 12 control parameters that determined the prosthesis mechanics throughout a gait cycle. The RL control design facilitated safe explorations of prosthesis mechanics with the human in the loop. Subjects were recruited and walked with a robotic transfemoral prosthesis on a treadmill while the RL controller tuned the control parameters. Stance time symmetry, step length symmetry, and bilateral anteroposterior (AP) impulses were measured. The data analysis showed that changes in robotic knee mechanics led to movement variations in both lower limbs and therefore gait temporal-spatial symmetry measures. Consistent across all the subjects, inter-limb AP impulse measurements explained gait symmetry: the stance time symmetry was significantly correlated with the net inter-limb AP impulse, and the step length symmetry was significantly correlated with braking and propulsive impulse symmetry. The results suggest that it is possible to personalize transfemoral prosthesis control for improved temporal-spatial gait symmetry. However, adjusting prosthesis mechanics alone was insufficient to maximize the gait symmetry. Rather, achieving gait symmetry may require coordination between the wearer’s motor control of the intact limb and adaptive control of the prosthetic joints. The results also indicated that the RL-based prosthesis tuning system was a potential tool for studying wearer-prosthesis interactions.
... In human studies, the effects of limb length discrepancy on ground reaction forces are inconsistent, with some indicating increased impact force on the shorter limb [15,16]. However, because humans are biped plantigrades and horses are quadruped unguligrades, and most human studies have been conducted at the walk, direct comparisons of results to this study are very difficult. ...
Article
Full-text available
This study has investigated the immediate effect of induced hindlimb length difference on hindlimb lameness measured as differences in minimum (Pmin) and maximum (Pmax) pelvic heights in 16 horses trotting in a straight line and lungeing on both hard and soft surfaces with body-mounted inertial sensors. Hindlimb length differences were induced by applying an Easyboot Glue-on shoe to one hindlimb. Changes in Pmin and Pmax with induced hindlimb length difference were assessed with a two-way repeated-measures ANOVA with trial (straight, lunge with inside limb elevation, lunge with outside limb elevation) and surface (hard, soft) as within-subject factors. Change in Pmin, indicating an impact-type lameness, in the hind limb with the elevation, was significant in both the straight line and while lunging on both hard and soft surfaces. Change in Pmax, indicating pushoff-type lameness, in the opposite, non-elevated hind limb, was significant when trotting in a straight line but not while lunging.
... This paper aimed to identify relationships between the level of functional and dynamic asymmetry and running velocity in advanced and intermediate-level runners. The data available in the literature indicate that the difference in the length of the lower limbs causes a pronounced asymmetry in gait [41,47] and a decline in locomotion economy [8,42,48]. In our study, the asymmetry of lower limb dimensions was small (up to 1 cm) and within the normal range [41,42]. ...
Article
Full-text available
Introduction. This paper aimed to establish relationships between the level of functional and dynamic asymmetry in advanced and intermediate-level runners and running velocity. Furthermore, evaluation of dynamic symmetry (running and vertical jump) was made using indices, taking into account the continuous character of the signals of the ground reaction force and angular positions in individual joints of the lower limb. Material and methods. Symmetry was assessed in a group of 12 Polish elite female middle-distance runners for the following parameters: 1) strength of lower limb muscles, 2) impulse of the vertical component of the ground reaction force during a CMJ jump, and 3) kinematics of a 50-m run in a straight line. Results. More advanced athletes (group A) were significantly taller and stronger than the athletes with less training experience (B). They were also characterized by a significantly longer step, a more extended swing phase, and a shorter support phase. There were no statistically significant differences between groups A and B in the level of asymmetry. Running velocity was significantly influenced by muscle strength symmetry (b = −5.77; p < 0.01) and support phase time symmetry (b = −6.64; p < 0.03). A reduction in each of these indices leads to an increase in running velocity. Conclusion. No morphological or functional asymmetry was found in female middle-distance runners with different training experience.
... Acute discrepancy in limb length may be less well tolerated than a congenital one and can cause significant morbidity. An acute LLD with as little as 5 mm is reported to be associated with back and hip pain, while a simulated discrepancy of 10 mm causes significant increase in postural sway [1,6,18,21,23]. Betsch et al. [6] reports that LLD >20 mm leads to significant changes in spinal posture. LLD also alters gait mechanics since the longer limb has increased pressures in the push-off phase, and degenerative changes in articular cartilage may occur under increased load levels [11,12]. ...
Article
Full-text available
Introduction: Locked intramedullary nailing (IMN) is the standard treatment for femoral shaft fractures in adults with high rates of union and relatively low rates of complications. Leg length discrepancy (LLD) after IMN of femoral shaft fractures is common, and is reported in 20–43% of cases. A known surgical challenge when trying to obtain equal leg lengths is comminuted fracture, which results in a loss of bony landmarks that guide reduction. The purpose of this study was to assess the effect of inherent tibial asymmetry on LLD measurements after IMN. Methods: Postoperative CT scanograms were performed on 79 consecutive patients after locked IMN for comminuted femoral shaft fracture. Leg lengths were determined by measurements taken from the scout view of a CT scanogram. Calculations of discrepancy were made for both femurs, tibias, and total leg length. Assessment was also made on the frequency wherein the tibial discrepancy compounded the femoral discrepancy. In situations where a limb segment was exactly symmetric to the contralateral side, the total leg was not regarded as a having compounded asymmetry. Results: Notable discrepancies were found in tibial length that significantly departed from the null of symmetry (p < 0.0001). Forty-two patients (53.2%) were found to have a tibial asymmetry of 3 mm or more, and 20 patients (25.3%) were found to exhibit a difference of 6.3 mm or more. Median femoral discrepancy was 5.3 mm and median tibial discrepancy was 3.0 mm. Seven patients were found to be asymmetric in total leg length as a consequence of underlying tibial asymmetry. Conversely, 11 patients benefited from their tibial asymmetry, which compensated for femoral asymmetry after IMN. Conclusion: Tibial symmetry cannot be assumed. If not accounted for, inherent tibial asymmetry may influence LLD after IMN of femur fractures.
... 1 Patients eventually develop a compensatory mechanism involving the kinematics of joint, repositioning of bone, and changes in lower limb attitude during course of time as an adaptation process. 2 Several complications may arise as a result of LLD, for example, lower back pain, 3 scoliosis, hip and knee osteoarthritis, 1 plantar fasciitis, ankle and foot pain, and pressure sore. [4][5][6] Studies have shown that LLD has its effect on kinematics and biomechanics of the skeletal system and gait. 7 Current consensus suggests the discrepancy does not reach significant level until approximately 2 cm of LLD. ...
Article
Full-text available
Introduction Limb length discrepancy (LLD) of lower extremities is underdiagnosed due to compensatory mechanisms during locomotion. The natural course of compensation leads to biomechanical alteration in human musculoskeletal system leading to adverse effects. General consensus accepts LLD more than 2 cm as significant to cause biomechanical alteration. No studies were conducted correlating height and lower extremities true length (TL) to signify LLD. Examining significant LLD in relation to height and TL using dynamic gait analysis with primary focus on kinematics and secondary focus on kinetics would provide an objective evaluation method. Methodology Forty participants with no evidence of LLD were recruited. Height and TL were measured. Reflective markers were attached at specific points in lower extremity and subjects walked in gait lab at a self-selected normal walking pace with artificial LLDs of 0, 1, 2, 3, and 4 cm simulated using shoe raise. Accommodation period of 30 min was given. Infrared cameras were used to capture the motion. Primary kinematic (knee flexion and pelvic obliquity (PO)) and secondary kinetic (ground reaction force (GRF)) were measured at right heel strike and left heel strike. Functional adaptation was analyzed and the postulated predictor indices (PIs) were used as a screening tool using height, LLD, and TL to notify significance. Results There was a significant knee flexion component seen in height category of less than 170 cm. There was significant difference between LLD 3 cm and 4 cm. No significant changes were seen in PO and GRF. PIs of LLD/height and LLD/TL were analyzed using receiver operating characteristic curve. LLD/height as a PI with value of 1.75 was determined with specificity of 80% and sensitivity of 76%. Conclusion A height of less than 170 cm has significant changes in relation to LLD. PI using LLD/height appears to be a promising tool to identify patients at risk.
... An increase of 2 cm or 3.7% in leg length difference has dramatic overall gait asymmetry, especially in vertical reaction forces during push off and initial contact (Kaufman et al., 1996). Further, LLD causes abnormal changes in foot loading patterns and increases in joint torques/moments, which could lead to long-term effects (Perttunen et al., 2004). Finally, studies have also shown that LLD causes more overall strain on the body and leads to increased expenditure of energy (Gurney et al., 2001). ...
Article
Full-text available
Physical changes such as leg length discrepancy, the addition of a mass at the distal end of the leg, the use of a prosthetic, and stroke frequently result in an asymmetric gait. This paper presents a metric that can potentially serve as a benchmark to categorize and differentiate between multiple asymmetric bipedal gaits. The combined gait asymmetry metric (CGAM) is based on modified Mahalanobis distances, and it utilizes the asymmetries of gait parameters obtained from motion capture and force data recorded during human walking. The gait parameters that were used in this analysis represent spatio-temporal, kinematic, and kinetic parameters. This form of a consolidated metric will help researchers identify overall gait asymmetry by showing them if the overall gait symmetry is improving and avoid the case where one parameter's symmetry is improving while another is getting worse. The CGAM metric successfully served as a measure for overall symmetry with eleven different gait parameters and successfully showed differences among gait with multiple physical asymmetries. The results showed that mass at the distal end had a larger magnitude on overall gait asymmetry compared to leg length discrepancy. It also showed that the combined effects are varied based on the cancelation effect between gait parameters. The metric was also successful in delineating the differences of prosthetic gait and able-bodied gait at three different walking velocities.
... This gait can be caused by physiological or mechanical factors [1]. Some physiological causes include unilateral stroke [2,3] and cerebral palsy [4], while the mechanical causes include significant leg-length discrepancy [5], unilateral osteoarthritis [6,7] and use of orthosis for post-operative recovery [8]. In a healthy gait, hamstrings, i.e. semimembranosus, semitendinosus and biceps femoris, and quadriceps, i.e. vastus intermedius (VI), vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles are responsible for the knee flexion and extension, respectively [9]. ...
Article
Asymmetrical stiff knee gait is a mechanical pathology that can disrupt lower extremity muscle coordination. A better understanding of this condition can help identify potential complications. This study proposes the use of dynamic musculoskeletal modelling simulation to investigate the effect of induced mechanical perturbation on the kneeand to examine the muscle behaviour without invasive technique. Thirty-eight healthy participants were recruited. Asymmetrical gait was simulated using knee brace. Knee joint angle, joint moment and knee flexor and extensor muscle forces were computed using OpenSim. Differences inmuscle force between normal and abnormal conditions were investigated using ANOVA and Tukey-Kramer multiple comparison test.The results revealed that braced knee experienced limited range of motion with smaller flexion moment occuring at late swing phase. Significant differences were found in all flexormuscle forces and in several extensor muscle forces (p<0.05). Normal knee produced larger flexor muscle force than braced knee. Braced knee generated the largest extensor muscle force at early swing phase. In summary, musculoskeletal modelling simulation can be a computational tool to map and detect the differences between normal and asymmetrical gaits.Graphical abstract
... Asymmetric alignment in the lower extremity has been suggested to lead to asymmetric gait (Perttunen et al., 2004), and it could increase the risk for running injury (Rauh et al., 2007). Most runners become injured on a particular side. ...
Article
Long-distance running results in lowering of the foot medial longitudinal arch, but it is unknown whether the left and right arches decrease equally. This study aimed to determine whether foot arch asymmetry increases upon completion of a full marathon and to identify factors capable of explaining the degree of asymmetry of navicular height and navicular height displacement. The three-dimensional foot posture data of 74 collegiate runners were obtained using an optical foot scanner system before (PRE) and immediately after (POST) a full marathon. The navicular height and arch height ratio (normalised navicular height by foot length) of both feet significantly decreased from PRE to POST full marathon completion (44.3 ± 6.3 mm versus 40.8 ± 6.5 mm, 17.8 ± 2.5 versus 16.6 ± 2.7, respectively; p < 0.001, both). The asymmetry of the arch height ratio was significantly greater POST than PRE marathon. Multiple linear regression analysis indicated that the POST-race Asymmetry Index (AI) of navicular height was significantly predicted by the PRE-race AI of navicular height; navicular height displacement was predicted by PRE-race navicular height and the marathon time. Full marathon running induced increasing asymmetry and lowering of the medial longitudinal arch in runners.
... 1970 ; Damholt et termansen, 1978 ;Hirasawa, 1979 ;Claeys, 1983 ;Hamil et al., 1984 ;Matsusaka et al., 1985 ;Burnie et Brodie, 1986 ;Pierroti et al., 1991 ;Hesse et al., 1997 ;. Crowe et al., 1996Sadeghi et al., bis, 2002Sadeghi et al., , 2003Pettunen et al., 2004). Blanc et al. (1999) utilisent un test plus rare, le Hoteling's T 2 . ...
... Many researchers have discussed functional asymmetries with differential contributions to propulsion and control between limbs [3][4][5][6][7][8][9]. However, movement asymmetries, including those observed during gait, are more commonly associated with a higher risk of injury and pathology along with accelerated disease progression [10][11][12][13][14][15][16][17][18][19]. ...
Article
Full-text available
Context Movement and loading asymmetry are associated with an increased risk of musculoskeletal injury, disease progression, and suboptimal recovery. Osteopathic structural screening can be utilized to determine areas of somatic dysfunction that could contribute to movement and loading asymmetry. Osteopathic manipulation treatments (OMTs) targeting identified somatic dysfunctions can correct structural asymmetries and malalignment, restoring the ability for proper compensation of stresses throughout the body. Little is currently known about the ability for OMTs to reduce gait asymmetries, thereby reducing the risk of injury, accelerated disease progression, and suboptimal recovery. Objectives To demonstrate whether osteopathic screening and treatment could alter movement and loading asymmetry during treadmill walking. Methods Forty-two healthy adults (20 males, 22 females) between the ages of 18 and 35 were recruited for this prospective intervention. Standardized osteopathic screening exams were completed by a single physician for each participant, and osteopathic manipulation was performed targeting somatic dysfunctions identified in the screening exam. Three-dimensional (3-D) biomechanical assessments, including the collection of motion capture and force plate data, were performed prior to and following osteopathic manipulation to quantify gait mechanics. Motion capture and loading data were processed utilizing Qualisys Track Manager and Visual 3D software, respectively. Asymmetry in the following temporal, kinetic, and kinematic measures was quantified utilizing a limb symmetry index (LSI): peak vertical ground reaction force, the impulse of the vertical ground reaction force, peak knee flexion angle, step length, stride length, and stance time. A 2-way repeated-measures analysis of variance model was utilized to evaluate the effects of time (pre/post manipulation) and sex (male/female) on each measure of gait asymmetry. Results Gait asymmetry in the peak vertical ground reaction force (−0.6%, p=0.025) and the impulse of the vertical ground reaction force (−0.3%, p=0.026) was reduced in males following osteopathic manipulation. There was no difference in gait asymmetry between time points in females. Osteopathic manipulation did not impact asymmetry in peak knee flexion angle, step length, stride length, or stance time. Among the participants, 59.5% (25) followed the common compensatory pattern, whereas 40.5% (17) followed the uncommon compensatory pattern. One third (33.3%, 14) of the participants showed decompensation at the occipitoatlantal (OA) junction, whereas 26.2% (11), one third (33.3%, 14), and 26.2% (11) showed decompensation at the cervicothoracic (CT), thoracolumbar (TL), and lumbosacral (LS) junctions, respectively. Somatic dysfunction at the sacrum, L5, right innominate, and left innominate occurred in 88.1% (37), 69.0% (29), 97.6% (41), and 97.6% (41) of the participants, respectively. Conclusions Correcting somatic dysfunction can influence gait asymmetry in males; the sex-specificity of the observed effects of osteopathic manipulation on gait asymmetry is worthy of further investigation. Osteopathic structural examinations and treatment of somatic dysfunctions may improve gait symmetry even in asymptomatic individuals. These findings encourage larger-scale investigations on the use of OMT to optimize gait, prevent injury and the progression of disease, and aid in recovery after surgery.
... Since the leg length differences may affect measured parameters during jogging, the intera-limb symmetry, and the length of the participants' legs were measured. We ensured that the differences between the bodies in any participant was not more than 1 cm [14]. The participants had right dominant lower extremities that were determined using the preferred leg method for ball kicking and hopscotch [1]. ...
Article
Full-text available
Purpose: Evaluation of joints behavioral symmetry of the lower limbs to produce a smooth, rhythmic movement is one of the topics in the field of biomechanics of running. This study investigated joints local and global symmetry while jogging in young male athletes. Methods: This was a quasi-experimental study. Random sampling method was used and the participants of the study included 15 healthy young male athletes (Mean±SD age=27.14±3.67 years, Mean±SD height=176.57±5.06 cm, Mean±SD weight=69.84±6.13 kg). A 6-camera motion analysis system synchronized with 2 force plate devices and a 3D Marker-set were used for data collection. Participants ran with 155 bpm step frequency controlled by a metronome. After filtering the data, kinematic and kinetic parameters were calculated using inverse dynamics method and the calculated data were normalized based on body weight and 100% running gait cycle. Paired student t-test at the significance level of 0.05 was used for determining the differences between the selected peaks of ankle, knee and hip joints moment of the dominant and Non dominant limbs. The principal component analysis technique was used on the support phase of the sagittal plane joint moment in order to compare and evaluate functional asymmetry and identify each joint (local symmetry) and lower limb actions (global symmetry). SPSS was used for statistical analysis. Results: Based on the findings, there were no significant differences in spatio-temporal parameters of the dominant and Non dominant limbs. Although, principal component analysis detected different functional tasks for similar joints, the same tasks were identified for the lower limbs using this method. Conclusion: It seems that local asymmetry and global symmetry occurs during jogging in young male athletes and central nervous system compensatory mechanisms might play an important role in this matter.
Article
Objective: Patient adherence is a challenge in offloading diabetic foot ulcers (DFUs) with removable cast walkers (RCWs). The size and weight of an RCW, changes to gait, and imposed limb length discrepancies may all discourage adherence. This study sought to determine whether RCW size and provision of a contralateral limb lift affected users' comfort and gait. Research design and methods: Twenty-five individuals at risk for DFUs completed several 20-m walking trials under five footwear conditions: bilateral standardized shoes, a knee-high RCW with shoe with or without an external shoe lift contralaterally, and an ankle-high RCW with shoe with or without an external shoe lift contralaterally. Perceived comfort ratings were assessed through the use of visual analog scales. Spatial and temporal parameters of gait were captured by an instrumented walkway, and plantar pressure was measured and recorded using pedobarographic insoles. Results: The bilateral shoes condition was reported to be most comfortable; both RCW conditions without the lift were significantly less comfortable (P < 0.01). In contrast to the ankle-high RCW, the knee-high RCW resulted in significantly slower walking (5.6%; P < 0.01) but greater offloading in multiple forefoot regions of the offloaded foot (6.8-8.1%; P < 0.01). Use of the contralateral shoe lift resulted in significantly less variability in walking velocity (52.8%; P < 0.01) and reduced stance time for the offloaded foot (2.6%; P = 0.01), but it also reduced offloading in multiple forefoot regions of the offloaded foot (3.7-6.0%; P < 0.01). Conclusions: Improved comfort and gait were associated with the ankle-high RCW and contralateral limb lift. Providing this combination to patients with active DFUs may increase offloading adherence and subsequently improve healing.
Article
Full-text available
Limb length inequality results from many types of musculoskeletal disorders. Asymmetric weight bearing from a limb length discrepancy of less than 2% can have debilitating consequences such as back problems and early-onset osteoarthritis. Existing treatments include invasive surgeries and/or drug regimens that are often only partially effective. As a noninvasive alternative, we previously developed a once daily limb-heating model using targeted heat on one side of the body for 2 weeks to unilaterally increase bone length by up to 1.5% in growing mice. In this study, we applied heat for 1 week to determine whether these small differences in limb length are functionally significant, assessed by changes in hindlimb weight bearing. We tested the hypothesis that heat-induced limb length asymmetry has a functional impact on weight bearing in mouse hindlimbs. Female 3-week-old C57BL/6 mice (N = 12 total) were treated with targeted intermittent heat for 7 days (40 C for 40 min/day). High-resolution x-ray (N = 6) and hindlimb weight bearing data (N = 8) were acquired at the start and end of the experiments. There were no significant left-right differences in starting tibial length or hindlimb weight bearing. After 1-week heat exposure, tibiae (t = 7.7, p < 0.001) and femora (t = 11.5, p < 0.001) were ~1 and 1.4% longer, respectively, on the heat-treated sides (40 C) compared to the non-treated contralateral sides (30 C). Tibial elongation rate was over 6% greater (t = 5.19, p < 0.001). Hindlimb weight bearing was nearly 20% greater (t = 11.9, p < 0.001) and significantly correlated with the increase in tibial elongation rate on the heat-treated side (R2 = 0.82, p < 0.01). These results support the hypothesis that even a small limb length discrepancy can cause imbalanced weight distribution in healthy mice. The increase in bone elongation rate generated by localized heat could be a way to equalize limb length and weight bearing asymmetry caused by disease or trauma, leading to new approaches with better outcomes by using heat to lengthen limbs and reduce costly side effects of more invasive interventions.
Article
Objectives: Limb lengthening after total knee arthroplasty (TKA) has been reported in some cases, all of which were evaluated using 2-dimensional images. To our knowledge, no case has been evaluated using 3-dimensional (3D) images. We investigated 3D limb lengthening after TKA. Methods: We simulated 100 varus knees using 3D templating software. Virtual TKA was performed to maintain the original joint line by conducting a measured-resection technique. We examined the relationships of 3D distance between the femoral head center and ankle center before and after TKA, degree of hip–knee–ankle angle (HKA) improvement, and degree of flexion contracture angle improvement. Results: All cases showed limb lengthening (average, 9.4 ± 6.0 mm). The coefficients of correlation with limb lengthening and the degree of HKA improvement and the degree of flexion contracture angle improvement were good (0.730 and 0.751, respectively). The correlation between the degree of total improvement (the degree of HKA improvement + the degree of flexion contracture angle improvement) and limb lengthening was strong (r = 0.896). Conclusions: The expected limb lengthening when performing measured-resection TKA is expressed as 0.58 × (the degree of HKA improvement + the degree of flexion contracture angle improvement) mm and is a useful index.
Article
Objective: Klippel-Trénaunay syndrome (KTS) is described in the literature as a complex syndrome characterized by various combinations of capillary, venous, and lymphatic malformations associated with limb overgrowth. In the first description by Maurice Klippel and Paul Trénaunay, tridimensional bone hypertrophy was believed to be the cause of limb enlargement. The purpose of this study was primarily to assess the presence of real bone hypertrophy as a cause of enlargement of the limb and to underline the rare presence of undergrowth of the affected limb in patients with KTS. Methods: A two-center retrospective review including 17 KTS patients with various combinations of capillary, venous, and lymphatic malformation affecting the lower limb was performed. Differences in limb dimension were evaluated clinically. Width and length discrepancy of the affected limb was measured with radiologic imaging. Results: We found an increase of length in the affected limb in 80% of the patients. The leg length discrepancy varied from 0.2 to 2.6 cm. The median leg length discrepancy was found to be 1.4 cm. Three patients had a reduced length of the affected limb. Girth enlargement of the affected extremity was noticed in 60% of the patients, and 2 of 17 patients had hypotrophy of the involved limb. Hypertrophy (an increase in both length and width) of the bone was found in none of our cases, and the circumferential enlargement of the affected extremity was related only to soft tissue enlargement. Conclusions: In the literature, KTS is considered the prototype of overgrowth syndromes associated with complex vascular malformations. The majority of our patients showed limb length increase associated with soft tissue enlargement without an increase of bone width; there were also two patients with limb undergrowth. A real bone overgrowth (an increase in both length and width) was not present in our patients. Therefore, we could consider the absence of real bone hypertrophy as probably a new aspect of such confusing and controversial definitions of KTS. In addition, it would be more accurate to classify KTS patients on the basis of their phenotypic features (type of vascular malformation, types of overgrown tissue) rather than by use of an outdated eponym.
Article
Full-text available
Background and Objectives: Gait asymmetry is a useful index that can provide an important role in clinical treatment. Since the link between asymmetry index of gait ground reaction force frequency content and hearing loss is not well evaluated, the aim of this study was to compare the asymmetry index of gait ground reaction force frequency spectrum in deaf and hearing male children of Hamedan city. Material and Methods: In this descriptive study, 30 male children from Hamedan city in 2017 were selected and equally divided into a healthy group and a group with hearing loss problems (deaf group). Frequency content of ground reaction forces were analyzed during barefoot walking. Then, asymmetry indices were computed for essential number of harmonics, band width, median frequency, frequency with a power of 99.5%, and amplitudes of harmonics for three-dimensional groud reaction forces. Independent t-test was used for data analysis. Results: Hearing loss was associated with increased asymmetry index of anterior-posterior median frequency (by 10%; p=0.011) and anterior-posterior frequency band width (by 6%; p=0.022). Similar asymmetry index of vertical and medio-lateral frequency content were found in both groups (p>0.05). Conclusion: The greatest asymmetry index value of ground reaction force frequency content in deaf children was in anterior-posterior direction. Also, the highest differences in asymmetry indices were in median frequemcy, band width, and harmonic amplitude during walking. In order to improve above mentioned asymmetry indices, using treatment interventions in deaf children are suggested.
Article
Background: Foot orthoses are often used to correct altered gait patterns. However, effect of long term use of arch support foot orthoses on walking mechanics is not well understood. The aim of this study was to evaluate the effects of long term use of arch support foot orthoses on the asymmetry indices of ground reaction forces during stance phase of walking in male children with flexible flat feet. Methods: Fifteen male volunteered children (with their parents' permission) with flexible flat feet were evaluated. Walking ground reaction forces and kinematic data before and after four months use of foot orthoses were recorded by force plate and Vicon motion system, respectively. Then, the asymmetry indices of ground reaction force components were calculated. Results: The results show that asymmetry index of the medio-lateral component of ground reaction force in loading response and push off phases during pre-test were higher than 4% (normal value). Also asymmetry index of its time to peak during the mid-stance phase in the pre-test were higher than normal value. Moreover, findings did not show any significant differences in asymmetry indices of other ground reaction force components and their time to peak, impulses and vertical loading rate between pre-test and post-test conditions. Conclusion: Despite the high asymmetry values of the peak medio-lateral component and it's time to peak in children with flexible flat feet during pre-test; long-term use of the foot orthoses did not show any significant effect on the improvement of the asymmetry index of these components. However, long-term wearing of the foot orthoses reduced asymmetry index of the peak positive free moment amplitude.
Article
Background and Objective: The asymmetry index during walking can be used for clinical treatment. This study was done to determine the immediate and long-term effects of foot orthoses on asymmetry of ground reaction forces frequency spectrum in male children with flat foot during walking. Methods: This clinical trial study was done on fifteen children with flat foot. Subjects were randomly divided into without foot orthoses, immediate and long term usage of foot orthoses groups. The kinematic and kinetic data during three without foot orthoses, immediate and long term use of foot orthoses conditions were recorded by the motion analysis and force platform systems, respectively. Results: Asymmetry index of medio-lateral frequency spectrum component during walking without foot orthoses, immediate and long term use of orthoses in median frequency and band width were greater than 4 percent. There were not any significant differences in asymmetry index of ground reaction force frequency spectrum components, asymmetry index of essential harmony numbers, asymmetry index of essential harmony total powers, and asymmetry index of fundamental harmony number in vertical, anterior-posterior, and medio-lateral axes between without foot orthoses, immediate and long term use of foot orthoses conditions. However, asymmetry index of essential harmony total power in medio-lateral axis during immediate use of foot orthoses tend to be reduced than that walking without foot orthoses. However, this difference was not significant. Conclusion: Despite the high asymmetry index of the ground reaction force frequency spectrum in the medio-lateral component during walking without foot orthoses, immediate and long-term effects of foot orthoses in the median and bandwidth frequency variables, the acute or long term use of foot orthoses did not show any significant effect on improvement of asymmetry index of ground reaction force frequency spectrum components.
Article
Background: The aim of this study was to evaluate the influence of leg length discrepancy in geriatric patients with early failure of bipolar hemiarthroplasty and to identify related failure patterns and risk factors. Methods: In this retrospective study, the risk factors of early acetabulum failure within 5 years of hemiarthroplasty for displaced femoral neck fracture were compared with a control group of patients who had implant survival for at least 5 years after hemiarthroplasty. The basic data, leg length discrepancy, femoral offset, and the shell size were evaluated. Results: Of all risk factors, there was a significant difference in increased leg length between the two groups. The mean difference in leg length was 7.8 ± 5.9 mm in the early acetabular failure group and -1.7 ± 6.2 mm in the control group. For an increase in leg length of >6 mm, the odds ratio of early acetabular failure was 25-fold greater when compared with the control group. Conclusion: Increased leg length was significantly associated with early acetabular failure after bipolar hemiarthroplasty for femoral neck fracture among geriatric patients. It is critical to avoid increase in leg length after bipolar hemiarthroplasty.
Article
This study aimed to investigate: (1) the prevalence and magnitude of breast movement asymmetry, (2) the interaction between static and dynamic breast asymmetry and (3) the influence of sports bras on breast asymmetry during running. Position data were collected from 167 females whilst treadmill running and then a sub-group of 12 participants in different bra conditions. Breast movement asymmetry existed in 89% of participants, with resultant static breast position asymmetry larger in participants displaying dynamic asymmetry. Asymmetry was most commonly caused (60% to 75%) by greater movement of the left breast. No significant relationships were found between asymmetry and bra size or breast pain. Sports bras reduced asymmetry prevalence from 75% to 33% of participants in the antero-posterior direction but only from 75% to 67% of participants in the infero-superior direction. The magnitude of range-of-motion asymmetry reduced from 67 mm with no bra to between 6 and 64 mm in-bra in the infero-superior direction, with the best performing bra incorporating encapsulating cups and adjustable straps and underband. It is recommended that sports bras allow underband and strap adjustment to facilitate individual breast support and that asymmetry is considered when designing and fitting bras, which could utilise resultant asymmetry measured statically.
Article
Full-text available
Background: The literature reports evidence of leg length discrepancy (LLD) associated with musculoskeletal disorders, alterations in spinopelvic alignment, and body posture, leading to low back pain and lumbar scoliosis. The most common conservative treatment for LLD is the use of internal or external shoe lifts although no treatment guidelines have been established. Aim: The study aimed to contribute to low back pain–LLD relationship comprehension, highlighting the benefits of LLD correction in the nonspecific low back pain (NSLBP) population. Methods: A cross-sectional observational study recruited a cohort of 80 NSLBP patients (48 females, 32 males) with LLD, age ( μ = 35 ± 17.2). Entire body posture, including 3-D spine shape reconstruction, was measured using a nonionizing 3-D optoelectronic stereophotogrammetric approach. After the first 3-D posture evaluation, patients were provided with customized orthotics, including 100% LLD heel lift correction. No other therapeutic interventions were considered. Pain level was assessed using the numerical pain rating scale (NPRS). The gender, age-related, and time-dependent effects of LLD equalization treatment in NSLBP patients was investigated during 2 years of follow-up. The statistical analysis was performed at the global level using multivariate methods by Hotelling T ² tests and intrasubject-level using t -test. Results and Discussion: An initial average NPRS = 7.8 was determined. In the medium-term follow-up group (4 months), the NPRS dramatically decreased (NPRS = 1.1). The pain disappeared in the long-term (2 years) follow-up group (NPRS = 0). The study results highlight that LLD equalization treatment led to clear statistically significant improvements in all the postural parameters of the frontal plane, including the underfoot load asymmetry. No worsening has been detected. An adaptation period long enough is needed to obtain progressive pain relief improvements and structural posture changes. Younger NSLBP patients showed slightly better improvements than older ones. Minimal differences between healthy young adults’ and NSLBP patients’ postures were found either in natural erect standing posture or when LLD equalization is applied. Conclusion: Heel-lift customized orthotics with 100% LLD correction are an effective short- and long-term treatment in patients with nonspecific LBP, inducing pain symptom recession and stimulating the improvement of postural parameters without contraindications.
Article
The purpose of this study was to investigate the effects of real-time visual bio-feedback during walking on the symmetry of the elderly gait. The subjects of this study were 16 elderly men (80.3 ± 4.6 years, 163.0 ± 4.7 cm, 64.7 ± 9.4 kg). They were asked to walk on a treadmill at the preferred speed, and later biofeedback was provided so that the subject could visually confirm the vertical ground reaction force of the both feet in real-time. The variables include three dimensional lower limb joint angle and bilateral symmetry index. As a result, the ROM of dorsi-flexion and plantar-flexion at the ankle joint was increased in the stance and swing phase after providing the visual biofeedback (p < .05). In addition, the symmetry index of double stance, single stance, ROM of hip AA at stance phase, and M/L COP range were decreased after providing the visual biofeedback (p < .05). The results suggested that the visual bio-feedback provided in real-time may have a positive effect on the symmetrical walking of the elderly. It is warranted whether gait exercise program using biofeedback would have a long term effect in future studies.
Article
Purpose Gait analysis is an important index in the clinical treatment of people with anterior cruciate ligament (ACL) injury. Following unilateral ACL reconstruction (ACLR), the knee kinetic asymmetries are likely to affect the gait cycle. Therefore, the aim of this study was to examine the symmetries of vertical ground reaction force (vGRF) and select the knee muscle activity in gait cycles in participants with and without unilateral ACLR. Methods In this cross-sectional study, vGRF and muscle activity data in difference gait cycles were collected from 56 male subjects (28 with unilateral ACLR and 28 healthy subjects) using force plate and electromyography (EMG), respectively. MATLAB software was used for data analysis and independent t test was employed to compare the two groups. Results No significant difference was seen between the two groups in the variable of first peak force symmetry (n.s). However, there was a significant difference in the second-peak force symmetry index between the two groups (p ≤ 0.001). Regarding muscle activity symmetry in the braking phase of gait, a significant difference was observed in rectus femoris between the two groups (p ≤ 0.001), while no difference was seen in medial gastrocnemius and biceps femoris activity (n.s). In the propulsive phase of gait, there was a significant difference in medial gastrocnemius and biceps femoris muscles activity between the two groups (p ≤ 0.001), while no difference was found in rectus femoris muscle activity (n.s). Conclusions The results revealed that unilateral ACLR creates asymmetry in vGRF and muscle activities in different phases of the gait cycle. So, more attention should be paid to this problem in clinical settings, and also to the use of therapeutic interventions to reduce the amount of kinetic asymmetries. Level of evidence III.
Article
Introduction We conducted a prospective study to find out change in limb length (lengthening/shortening) after total knee arthroplsty in unilateral and bilateral total knee arthroplasty (TKA) because few literature is available regarding limb length discrepancy in TKA in comparison to total hip arthroplasty. Limb length discrepancy (LLD) may lead to low back pain and gait abnormalities. Material and methods We divided 58 patients into two groups: Group A (28 patients) includes patients who underwent unilateral TKA and Group B (30 patients) includes patients who underwent bilateral TKA. We assessed the patients clinico-radiologically in terms of limb length (supine position), deformity, Sagital-flexion deformity/extensor lag, coronal - varus/valgus, range of motion, knee stability, patellar tracking and Hip-knee-ankle angle preoperatively and postoperatively. Results In group A, mean limb length difference (operated limb gained length as compared to unoperated limb) was 1.11 cm. Out of 22 patients (78%) in whom limb length discrepancy was present, only 7 patients (31%) having limb length discrepancy perceived it. In group B, mean limb length difference was 1.03 cm. Fourteen patients (47%) in group B had LLD but none of them perceived it. Clinically 22 patients (78%) in group A and 14 patients (47%) in group B had LLD. Radiologically 25 patients (89%) in group A and 22 patients (73%) in group B had LLD. Out of the 7 patients who perceived LLD, all had LLD radiologically too. Conclusion We reckoned that limb length discrepancy is more common in unilateral TKA. Limb length discrepancy of 2 cm or more is perceived by the patients operated for unilateral TKA. But in bilateral TKA, none of the patient perceived LLD because in this group LLD was less than 2 cm. Limb length discrepancy may leads to dissatisfaction of the patients and poor functional outcome.
Article
Background/Aims Diabetic patients with peripheral vascular manifestations often develop foot ulcers and sometimes have to undergo lower extremity amputation. This retrospective study investigated leg dominance and laterality of lower extremity amputation in diabetic, dysvascular amputees. Methods All patients who met the inclusion criteria had their medical records reviewed for their dominant side and a correlation with a side of amputation was analysed. This information is routinely obtained as part of the admission history. For the literature review, PubMed, Google Scholar, ScienceDirect and Cochrane Library were searched with no date restriction until February 2018. Relevant studies were included and analysed. Results Of all the patients (n=27), 16 had diabetes and of these, 12 (75%) had their dominant leg amputated. Conclusions The data and literature analysis suggest that diabetic, dysvascular patients' dominant legs may be at higher risk for amputation than the non-dominant side. Larger studies are needed to clarify the relationship between leg dominance and laterality of lower extremity amputation.
Article
Background Limb length discrepancy (LLD) is common and is associated with musculoskeletal disorders. Selection of adaptation strategies, the side more susceptible to complications, and the relationships between LLD magnitude and musculoskeletal complications are unclear. To elucidate these ambiguities, studies on gait parameters in LLD have been conducted. However, studies on inter-limb difference of mechanical work in LLD are rare. Research Question To investigate whether inter-limb differences in mechanical work in LLD and the relationship between LLD magnitude and mechanical work performed by each lower limb are significant. Methods Thirty-seven participants with LLD and without neuromuscular disorders disturbing normal gait were included. Three-dimensional motion analysis was conducted to obtain data on mechanical work, including joint work and the individual limb method (ILM) work. Mechanical work performed by the longer and shorter limbs was compared using paired t-test. Relationships between LLD and mechanical work were investigated using correlation and multiple regression analyses in both limbs. Eighteen participants had LLD > 20 mm, large group (LG), and 19 had LLD < 20 mm, small group (SG). Data exploration was conducted for the effect of LLD severity (LG vs. SG) on mechanical work. Results LLD showed significant inter-limb difference of mechanical work and negative correlations with positive and negative ILM work performed by the shorter limb. The shorter limb in SG performed significantly larger positive ILM work than the longer limb, whereas the longer limb in LG performed significantly larger negative ILM work than the shorter limb. Significance LLD showed inter-limb difference of ILM work and different adaptation strategies between LG and SG. These differences attribute to the decrease in ILM work performed by the shorter limb with the increase in LLD. Mechanical work including ILM work should be included in future studies to prevent complications and development of treatment methods for LLD.
Article
Full-text available
Introduction: Expectations for limb length differences after TKA are important for patient perception and outcomes. Limb length discrepancies may occur due to postoperative leg length increases, which can lead to decreased patient functionality and satisfaction and even possible litigation. The purpose of this study is to examine the frequency and extent of limb lengthening among various preoperative deformities and between two different implant systems. Methods: Preoperative and postoperative full-length standing radiographs were obtained between August 2018 and August 2019 to measure mechanical axis and limb length of operative limbs. Demographic information such as age, sex, and BMI was also collected. Patients were grouped into categories for pre- and postoperative subgroup analysis: valgus, varus, customized implant, and conventional implant. Regression analysis was performed to evaluate significant relationships. Results: Of the 121 primary TKAs analyzed, 62% of the knees showed an increase in limb length after TKA, with an average lengthening of 5.32 mm. Preoperative varus alignment was associated with a mean lengthening of 3.14 mm, while preoperative valgus alignment was associated with a mean lengthening of 16.2 mm. Overall, there were no statistically significant differences in limb lengths pre- and postoperatively (p = 0.23) and no significant changes in limb length for any subgroup. Further, no variables were associated with limb length changes (p = 0.49), including the use of customized implants (p = 0.2). Conclusions: Limb lengthening after TKA is common and, on average, occurs more significantly in valgus knees. No significant difference in limb lengthening could be demonstrated using customized over conventional implants. Preoperative counseling is important to manage patient expectations.
Article
Full-text available
BACKGROUND: Leg length discrepancy (LLD) may play a key role in exercise biomechanics. Although the Podoprint platform has been used in dynamic pressure studies, there are no data regarding the reliability and repeatability of dynamic measurements under simulated LLD conditions. OBJECTIVES: To determine the intra and intersession repeatability and reliability of dynamic parameters of the Podoprint pressure platform under simulated LLD conditions. DESIGN AND SETTING: Observational cross-sectional study at a public university. METHODS: Thirty-seven healthy volunteers participated in this study. LLD was simulated using ethyl vinyl acetate plantar lifts with heights of 5 mm, 10 mm, 15 mm and 20 mm located under the right shoe of each volunteer. The procedure was performed to capture the dynamic parameters of each participant under five different simulated LLD conditions. Stance time, mean pressure and peak pressure measurements were registered in three trials for each foot and each LLD level. Data were collected during two separate testing sessions, in order to establish intrasession and intersession reliability. RESULTS: The intraclass correlation coefficients (ICCs) for intrasession reliability ranged from 0.775 to 0.983 in the first session and from 0.860 to 0.985 in the second session. The ICCs for intersession reliability ranged from 0.909 to 0.990. Bland-Altman plots showed absence of systematic measurement errors. CONCLUSIONS: The results from this study indicate that the Podoprint platform is a reliable system for assessing dynamic parameters under simulated LLD conditions. Future studies should evaluate plantar pressures under LLD conditions, in association with exercise, biomechanics and musculoskeletal disorders.
Article
Gait asymmetry is defined as a loss of perfect agreement between the dominant and non-dominant lower limbs. Conflicting results from gait asymmetry studies may be due to different definitions of asymmetry, different research methods, and/or different variables and formulas used for asymmetry calculation. As a result, this makes it difficult to compare joint asymmetry values between studies. An accurate and precise understanding of asymmetry during human walking is an important step towards developing enhanced rehabilitation protocols for pathological gait. This study examined bilateral lower extremity joint moment asymmetry during the stance phase of walking using three different methods. Fourteen male children (with flat feet) aged 8–14 years participated in this study. The three-dimensional lower limb kinetics was evaluated during a comfortable gait. Then, right and left lower limb joint moments were used to calculate the joint moment asymmetry via three different methods (Lathrop-Lambach method: equation used by Lathrop-Lambach et al. (2014); Su method: equation used by Su et al. (2015); Nigg method: equation used by Nigg et al. (2013)). Repeated-measures ANOVAs (α = 0.05) were used to compare the values of net joint moment asymmetry calculated by the three methods. The results of the statistical analyses found that the amounts of moment symmetry between limbs calculated by the first two methods were significantly greater than that of using the Nigg method (except for the values of the frontal ankle moment computed by the Lathrop-Lambach method). Furthermore, in comparison of the first two methods, using the Su method showed a reduction in moment asymmetry for all joints and for all moments (p < 0.05). We conclude that, although all of three common methods for determining asymmetry between limbs have documented merit, they sometimes differ dramatically in results.
Article
Full-text available
The purpose of this study was to propose a measure of symmetry/asymmetry for normal human gait and to quantify symmetries/asymmetries of normal human gait for selected gait variables using a force platform. Sixty-two subjects performed ten gait trials each, stepping on the force platform five times with each leg. From these gait trials a symmetry index was calculated for 34 gait variables. The upper and lower limits of normal gait were calculated such that 95% of all symmetry indices obtained from this subject population fell within these limits. Upper and lower limits were found to vary from +/- 4% to over +/- 13,000%. Extremely high percentages were found for variables which had absolute magnitudes close to zero and/or variables which occurred at distinctly different instants during the gait cycle. The results of these variables need to be interpreted with caution.
Article
Full-text available
The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32+/-0.45 m and 11.90+/-0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump (P < 0.05-0.01). In addition, electromyograms of both legs Suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.
Article
Full-text available
As one of the most universal of all human activities, gait in the able-bodied has received considerable attention, but many aspects still need to be clarified. Symmetry or asymmetry in the actions of the lower extremities during walking and the possible effect of laterality on gait are two prevalent and controversial issues. The purpose of this study was to review the work done over the last few decades in demonstrating: (a) whether or not the lower limbs behave symmetrically during able-bodied gait; and (b) how limb dominance affects the symmetrical or asymmetrical behavior of the lower extremities. The literature reviewed shows that gait symmetry has often been assumed, to simplify data collection and analysis. In contrast, asymmetrical behavior of the lower limbs during able-bodied ambulation was addressed in numerous investigations and was found to reflect natural functional differences between the lower extremities. These functional differences were probably related to the contribution of each limb in carrying out the tasks of propulsion and control during able-bodied walking. In current debates on gait symmetry in able-bodied subjects, laterality has been cited as an explanation for the existence of functional differences between the lower extremities, although a number of studies do not support the hypothesis of a relationship between gait symmetry and laterality. Further investigation is needed to demonstrate functional gait asymmetry and its relationship to laterality, taking into consideration the biomechanical aspects of gait.
Article
The Paromed Datalogger® with two insole pressure transducers (16 sensors each, 200 Hz) was applied to study the feasibility of the system for measurement of plantar pressure distribution in ski jumping. The specific aim was to test the sensitivity of the Paromed system to the changes in plantar pressure distribution in ski jumping. Three international level ski jumpers served as subjects during the testing of the system. The Datalogger was fixed to the jumpers' lower back under the jumping suit. A separate pulse was transmitted to the Datalogger and tape recorder in order to synchronize the logger information with photocell signals indicating the location of the jumper on the inrun. Test procedure showed that this system could be used in ski jumping with only minor disturbance to the jumper. The measured relative pressure increase during the inrun curve matched well the calculated relative centrifugal force (mv2 · r-1), which thus serves a rough estimation of the system validity. Strong increase in pressure under the big toes compared to the heels (225% and 91%, respectively) with large interindividual differences characterized the take-off. These differences may reflect an unstable anteroposterior balance of a jumper while he tries to create a proper forward rotation for a good flight position.
Article
The proper management of LLD requires careful clinical and radiologic assessment, and repeated analysis of past growth in order to predict future growth. Treatment decisions must be re-evaluated constantly in the light of new leg length data and evolving surgical technique. Surgical treatment can be especially gratifying when anatomic, cosmetic, and functional symmetry is restored and a lifetime of shoe lifts, braces, or prostheses is avoided.
Article
The reliability of foot pressure measurement using the EMED F system has been tested by recording 25 walks with 10 volunteer subjects at three different speeds. Coefficients of reliability calculated for 1-25 walks showed that a good level of reliability was achieved using one measurement for most force/pressure variables but when the mean result of three or more walks was used reliability was excellent. Measurements related to time were more variable than the total force, the peak pressure and the area. The total force and peak pressure were also shown to increase with increasing speed but this was not true for all sites on the foot.
Article
This paper attempts to describe in what way cities might develop in a world confronted with the fact that in a few decades the fluid hydrocarbons, oil and gas, will no longer be available in unlimited amounts as energy sources.These considerations are made against a background of two global trends: a rapidly expanding global population, especially in areas where economic development is seriously hampered by a lack of access to adequate amounts of commercial energy, and the increasingly dangerous pollution of the atmosphere by human activity with its negative effects on the climate.A Second Solar Civilization, which returns to the energy sources of the First Solar Civilization, solar irradiance and its derivative forms wind, hydropower and biomass, is inevitable. The First Solar Civilization existed up until the time of the Industrial Revolution, when coal became available as an energy supply. The Second Solar Civilization will begin in the 21st century, when a dependence on fossil fuels will no longer be possible for reasons of scarcity and environmental incompatibility.The paper examines whether the energy services required in an efficiently functioning city, such as heating and lighting, industrial power supplies, mobility, and communications, can be provided by solar energy.A precondition is adjusting human requirements so that they can be met by energy sources of low energy density. Successful economies would use a minimal amount of energy, optimizing all conversion processes to achieve the highest efficiency at every step, and striving to achieve an economy which functions in closed material loops and with a solar energy supply.One of the most significant changes would occur in the transportation sector, which is even today no longer well served by the automobile, and the paper suggests which quality alternatives might be available. But social changes would also be called for. The separation of professional working vs private living spheres which has become tradition in industrialized countries would evolve into patterns favouring their integration.Such a low-energy economy of minimal energy intensity is possible if it is driven by innovation, technology and capital, and makes the fullest use of locally available renewable energy supplies.
The relationships between ground reaction forces, electromyographic activity (EMG), elasticity and running velocity were investigated at five speeds from submaximal to supramaximal levels in 11 male and 8 female sprinters. Supramaximal running was performed by a towing system. Reaction forces were measured on a force platform. EMGs were recorded telemetrically with surface electrodes from the vastus lateralis and gastrocnemius muscles, and elasticity of the contact leg was evaluated with spring constant values measured by film analysis. Data showed increases in most of the parameters studied with increasing running speed. At supramaximal velocity (10.36±0.31 m×s−1; 108.4±3.8%) the relative increase in running velocity correlated significantly (P<0.01) with the relative increase in stride rate of all subjects. In male subjects the relative change in stride rate correlated with the relative change of IEMG in the eccentric phase (P<0.05) between maximal and supramaximal runs. Running with the towing system caused a decrease in elasticity during the impact phase but this was significant (P<0.05) only in the female sprinters. The average net resultant force in the eccentric and concentric phases correlated significantly (P<0.05−0.001) with running velocity and stride length in the maximal run. It is concluded that (1) increased neural activation in supramaximal effort positively affects stride rate and that (2) average net resultant force as a specific force indicator is primarily related to stride length and that (3) the values in this indicator may explain the difference in running velocity between men and women.
Article
The symmetry index (SI), as one of methods to evaluate gait pattern in patients with leg-length discrepancy (LLD), helps to estimate the acceptable range of inequality and to determine symmetry in the kinematic and kinetic data before and after a heel lift, although this parameter has a large standard deviation that undermines its accuracy. Thirty patients with LLD were studied by a motion-analysis system and a force plate. Joint motion of the lower extremity in the sagittal plane, back movement in the coronal plane, and three-dimensional ground-reaction forces (GRFs) were registered. From a linear-regression analysis, a mean value of inequality of 2.33 cm (range, 2.12-2.54) was found to correspond to an acceptable gait symmetry. After a heel lift, the SI of the pelvic tilt at midstance and of the vertical GRF at initial contact increases significantly, but the SI of the medial GRF at terminal stance decreases. Patients with an inequality of a mean value of 0.51 cm determined by palpating bilaterally the top of the iliac crest (the TIC1 subgroup) showed a lesser value of the SI of the center of pressure in the forward direction during stance compared with the group with a mean value of inequality of 1.39 cm (the TIC2 subgroup). As a result of our findings, we conclude that the effect of the amount of correction by a heel lift on gait symmetry is unpredictable.
Article
The purpose of this paper is to address four aspects of surface electromyography associated with crosstalk between adjacent recording sites. The first issue that is addressed in the potential crosstalk between electrodes located on muscles with different functions: antagonist pairs, or muscles with one common and one different function (i.e. soleus/peroneus longus or soleus/ gastrocnemius). Practical functional tests are utilized to demonstrate the crosstalk between muscle pairs to be negligible. The second goal is to estimate the depth of pick-up and the crosstalk between myoelectric signals from agonist muscles using a theoretical model. The depth of pick-up was estimated to be 1.8 cm (including a 2 mm layer of skin and fat) using electrodes of 49 mm(2) with bipolar spacing of 2.0 cm. A cross-correlation technique is demonstrated which predicts the common signal (crosstalk) between surface electrodes with electrode-pair spacing of 1 cm around a hypothetical muscle. The predicted crosstalk using cross-correlation measures was 49% at 1 cm electrode-pair spacing dropping to 13% at 2 cm spacing and 4% at 3 cm. The third part compares these predictions with crosstalk measures from experimental recordings taken from electrode pairs spaced 2.5 cm apart around the quadriceps. At 2.5 cm spacing there was 22-24% common signal dropping to between 4-7% at 5 cm and to between 1 and 2% at 7.5 cm. The fourth and last component of this report assesses three methods to decrease the range of pick-up and thereby potential crosstalk: electrodes of smaller surface area, reduced bipolar spacing and mathematical differentiation. All three techniques reduce the common signal by varying amounts; all three techniques combined reduce the predicted crosstalk for the 1.0 cm electrode-pair spacing from 49-10.5%.
Article
The purpose of this study was to determine the effect of lower extremity asymmetry on the kinetic energy of the leg segments during ambulation. The equalization of leg length by means of a lift equalized the time durations for the four phases of a gait cycle. Leg length equalization also decreased the kinetic energy of the lower extremity segments for both legs despite a difference in the segmental masses of the two legs. J Orthop Sports Phys Ther 1982;3(3):105-107.
Article
The purpose of this study was to determine the effect of heel lifts on ground reaction force patterns in subjects with structural leg-length discrepancies (LLDs). Eighteen subjects with LLDs ranging from 4.8 to 22.2 mm participated in this study. Subject age range was from 20 to 63 years. A force platform was used to obtain ground reaction force data for four conditions. Data were collected prior to fitting of the heel lift and after a three-week break-in period. Data were analyzed by use of a two-factor within-subject analysis of variance for repeated measures. Before heel-lift fitting, maximum lateral force was greater in the short leg than in the long leg. After heel-lift fitting, maximum vertical force was greater within both legs, and maximum medical force was greater in the long leg than in the short leg. The results suggest that although heel lifts are used to achieve pelvic levelness, the use of heel lifts also resulted in increased ground reaction forces, which may cause increased joint stresses within the lower extremities.
Article
The association between different knee exertion injuries and lower limb malalignments was studied in 121 male athletes with knee exertion injuries and in 20 male athletes without knee symptoms. The associations between different malalignments was also analyzed. Leg length inequality (LLI), knee valgus, and different indexes of patellofemoral joint congruence were measured using radiological methods. Male athletes with patellar apicitis (n = 59) had significantly more LLI (P less than 0.001) and patella alta (P less than 0.05) than athletes without knee symptoms. The knee valgus was of the same numerical value in the shorter and longer leg sides in subjects with LLI of at least 5 mm (n = 58). A positive correlation was found between lateral patellar displacement (LPD) and patella alta (LT/LP) (P less than 0.001). Negative correlations were found between the sulcus angle (SA) and the lateral patello-femoral angle (LPA) (P less than 0.001) as well as between the LPD and the LPA (P less than 0.001).
Article
An accurate and simple radiographic method for the measurement of weight-bearing leg length inequality with a minimum of radiated body area is described. The measurement can be made in a conventional chest X-ray unit without other extra equipment than a gonad shield described here.
Article
An x-ray method is described for the determination of leg-length inequality in the standing subject, Its precision is compared to that of other methods in current use. The geometrical considerations which are inherent in any radiographic method of leg-length determination are summarized. Sixty-seven patients with OA hip were studied; 62 were considered to be idiopathic and 36 of these idiopathic cases were superolateral in type. Measurements in these 36 patients showed significant leg-length disparity, most of the diseased hips being found on the side of the longer leg. If allowance is made for shortening due to disease, the frequency and bias of the disparity are highly significant. The strong association between OA hip of this type and a long leg suggests a causal relationship.
Article
The possible association between pelvic obliquity and low-back pain is investigated in low-back pain patients and a control population. A precise method of erect posture radiography is used to carefully measure leg length inequality in these two groups. An age-related response of the postural scoliosis to shoe-raise is noted. The results of shoe-raise therapy with and without lumbosacral manipulation are compared, and preliminary results are reported.
Article
An economical method of recording peak pressures under the feet while standing or walking is described for clinical application. Normal values at 10 defined locations are presented. Correlation matrices indicate functional links between regions of support which influence patterns of deviation from the norms.
Article
One of the problems facing the clinician is the differentiation between functional and structural limb-length inequality. This study investigated 20 subjects (mean age, 9.0 +/- 3.9 years) with documented limb-length inequalities to determine the magnitude of discrepancies that result in gait abnormalities. The subjects were asked to walk on an 8-m walkway at a self-selected free pace. The contact time, first and second force peaks, and loading and unloading rates of the vertical ground-reaction force were measured for both limbs. These parameters were predictive for quantification of gait asymmetry. The asymmetry of these parameters increased as the limb-length inequality increased. In general, a limb-length inequality > 2.0 cm (3.7%) resulted in gait asymmetry that was greater than that observed in the normal population. However, the amount of asymmetry varied for each individual. A static examination can document an anatomic deformity, but this deformity may be compensated for by functional adaptations. An analysis of the patient's gait should be performed to identify asymmetries during ambulation. Dynamic gait findings, such as demonstrated in this study, are needed to support static measurements.
Article
We evaluated the gait of thirty-five neurologically normal children who had a limb-length discrepancy of the lower extremities that ranged from 0.8 to 15.8 per cent of the length of the long extremity (0.6 to 11.1 centimeters). The twenty-two boys and thirteen girls had an average age of thirteen years (range, eight to seventeen years). No patient had a substantial angular or rotational deformity of the lower extremities. We found no correlation between the actual discrepancy or the per cent discrepancy and any of the dependent kinematic or kinetic variables, including pelvic obliquity. Discrepancies of less than 3 per cent of the length of the long extremity were not associated with compensatory strategies. When a discrepancy was 5.5 per cent or more, more mechanical work was performed by the long extremity and there was a greater vertical displacement of the center of body mass. Clinically, this degree of discrepancy was manifested by the use of toe-walking as a compensatory strategy. Children who had less of a discrepancy were able to use a combination of compensatory strategies to normalize the mechanical work performed by the lower extremities.
Article
The longitudinal arch between the heel and the forefoot and the transverse arch between the first and fifth metatarsal heads, absorb shock, energy and force. A device to measure plantar pressure was used in 66 normal healthy subjects and in 294 patients with various types of foot disorder. Only 22 (3%) of a total of 720 feet, had a dynamic metatarsal arch during the stance phase of walking, and all had known abnormality. Our findings show that there is no distal transverse metatarsal arch during the stance phase. This is important for the classification and description of disorders of the foot.
Article
Patients who have limb-length discrepancy demonstrate an altered gait pattern or a limp. The purpose of this prospective study was to compare the objective gait parameters for the shorter lower limb with those for the longer lower limb before and after lengthening and to compare these data with those for a group of twenty subjects who had no limb-length discrepancy. Eighteen patients had equalization of limb length to within one centimeter. We analyzed the stance time, the second peak of the vertical ground-reaction-force vector, and the rate of loading with use of two force-plates arranged in a series. The difference in the mean stance times between the shorter and longer limbs before lengthening was 12 percent, whereas that after lengthening was 2.4 percent; the difference between the values before and after lengthening was significant (p<0.001). The difference in the stance times between the limbs of the patients who did not have limb-length discrepancy was 2 percent. Preoperatively, the mean second peak was 104 percent of body weight for the shorter limb compared with 116 percent for the longer limb; this difference was significant (p<0.001). After lengthening, the mean second peak for the shorter limb increased to 113 percent of body weight. The difference in the means for the second peak before and after lengthening was significant (p<0.001). With the numbers available, no significant difference was detected in the means for the second peak between the shorter and longer limbs after lengthening (p = 0.12). This study shows that lengthening of the shorter limb of patients who have limb-length discrepancy can normalize symmetry of quantifiable stance parameters and eliminate a limp.
Article
Patients with leg length discrepancy (LLD) develop compensatory mechanisms, which result in kinematic alterations in the lower limbs and pelvis. We investigated these compensatory mechanisms. Seven normal subjects underwent three-dimensional (3-D) gait analysis using a CODA MPX 30(R) analyser. The subjects were fitted with raises of varying heights to one lower limb and then analysed in static and dynamic modes. Pelvic obliquity was the most common mechanism used to compensate for small degrees of leg length discrepancy up to 2.2 cm, particularly in static standing. With larger degrees of discrepancy, the subjects developed flexion of the knee of the longer leg. Compensatory mechanisms during walking were more complex and included a combination of kinematic changes at the pelvis, knee and ankle. We developed mathematical models for the compensatory mechanisms at all the three levels. We conclude that 3-D gait analysis is a useful tool in the assessment of patients with functional and structural leg length discrepancies.
Congenital anomalies of lower extremity Campbell's Operative Orthopaedics
  • Jh Beaty
Beaty JH. Congenital anomalies of lower extremity. In: Crenshaw AH, ed. Campbell's Operative Orthopaedics. Eighth vol. 3. St. Louis: Mosby Year Book, 1992: 2126–2158.
Paromed datalogger instruction manual
  • Gmbh Paromed Medizintechnik
Paromed Medizintechnik GmbH. Paromed datalogger instruction manual. Neubeuern, Germany, 1995.
Biomechanical visualization technique
  • T Kokkonen
Kokkonen T. Biomechanical visualization technique. Master Thesis, Department of Mathematical Information Technology, University of Jyva¨skyla¨, Jyvda¨kyla¨, Finland, 1999.
Leg length discrepancy Lovell and Winter's Pediatric Orthopedics
  • Cf Moseley
Moseley CF. Leg length discrepancy. In: Morrisey RT, Weinstein SL, eds. Lovell and Winter's Pediatric Orthopedics. Fifth vol. 2. Philadelphia: Lippincott Williams & Wilkins, 2000: 1104–1150.
Asymmetries in ground reaction force patterns in normal human gait
  • W Herzog
  • B M Nigg
  • Ljo Read
  • E Isson
Herzog W, Nigg BM, Read LJO, Isson E. Asymmetries in ground reaction force patterns in normal human gait. Med Sci Sports Exerc 1989: 21: 110-114.
Gait asymmetry in patients with limblength inequality
  • K R Kaufinan
  • L S Miller
  • D H Sutherland
Kaufinan KR, Miller LS, Sutherland DH. Gait asymmetry in patients with limblength inequality. J Pediat Orthop 1996: 16: 144-150.
Plantar pressures during ski jumping take-off
  • M Virmavirta
  • P V Korni
Virmavirta M, Korni PV. Plantar pressures during ski jumping take-off.
  • Hamill J
The management of limb inequality
  • Mb
  • Menelaus