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Changing step width alters lower extremity biomechanics during running
Abstract
Step width is a spatiotemporal parameter that may influence lower extremity biomechanics at the hip and knee joint. The purpose of this study was to determine the biomechanical response of the lower extremity joints to step width changes during running. Lower extremity data from 30 healthy runners, half of them male, were collected during running in three step width conditions: preferred, wide, and narrow. Dependent variables and step width were analyzed using a mixed model ANOVA and pairwise t-tests for post hoc comparisons. Step width was successfully altered in the wide and narrow conditions. Generally, frontal plane peak values decreased as step width increased from narrow to preferred to wide. Peak hip adduction and rearfoot eversion angles decreased as step width increased from narrow to wide. Peak knee abduction moment and knee abduction impulse also decreased as step width increased from narrow to wide. Although men and women ran differently, gender only influenced the effect of step width on peak rearfoot inversion moment. In conclusion, step width influences lower extremity biomechanics in healthy runners. When step width increased from narrow to wide, peak values of frontal plane variables decreased. In addition to previously reported changes at the rearfoot, the hip and knee joint biomechanics were also influenced by changes in step width.
... Step width is a spatial variable in the frontal plane, defined as the mediolateral distance between the heels of bilateral feet at initial contact [11]. Variations in step width and the contributing factors are complex and diverse. ...
... Rearfoot eversion angle peaks and excursion were increased in normal and cross-over running but not during wider step conditions [31]. The kinematics and joint kinetics in the proximal joints (i.e. the knee and hip) are affected by the substantial alterations in step width [11,[32][33][34][35][36]. As the step width narrows in gait, the peak knee abduction moment and impulse decrease [11]. ...
... The kinematics and joint kinetics in the proximal joints (i.e. the knee and hip) are affected by the substantial alterations in step width [11,[32][33][34][35][36]. As the step width narrows in gait, the peak knee abduction moment and impulse decrease [11]. In contrast, the peak knee adduction moment and angular impulse increase [32], along with hip adduction and range of motion (ROM) in hip adduction [34,35,37]. ...
Background
Step width is a spatial variable in the frontal plane, defined as the mediolateral distance between the heel (forefoot during sprinting) of bilateral feet at initial contact. Variations in step width may impact the lower limb biomechanics. This systematic review aimed to synthesize the published findings to determine the influence of acute changes in step width on locomotion biomechanics and provide implications for injury prevention and enhanced sports performance.
Methods
Literature was identified, selected, and appraised in accordance with the methods of a systematic review. Four electronic databases (Web of Science, MEDLINE via PubMed, Scopus, and ScienceDirect) were searched up until May 2023 with the development of inclusion criteria based on the PICO model. Study quality was assessed using the Downs and Black checklist and the measured parameters were summarized.
Results
Twenty-three articles and 399 participants were included in the systematic review. The average quality score of the 23 studies included was 9.39 (out of 14). Step width changed the kinematics and kinetics in the sagittal, frontal, and transverse planes of the lower limb, such as peak rearfoot eversion angle and moment, peak hip adduction angle and moment, knee flexion moment, peak knee internal rotation angle, as well as knee external rotation moment. Alteration of step width has the potential to change the stability and posture during locomotion, and evidence exists for the immediate biomechanical effects of variations in step width to alter proximal kinematics and cues to impact loading variables.
Conclusion
Short-term changes in step width during walking, running, and sprinting influenced multiple lower extremity biomechanics. Narrower step width may result in poor balance and higher impact loading on the lower extremities during walking and running and may limit an athlete’s sprint performance. Increasing step width may be beneficial for injury rehabilitation, i.e., for patients with patellofemoral pain syndrome, iliotibial band syndrome or tibial bone stress injury. Wider steps increase the supporting base and typically enhance balance control, which in turn could reduce the risks of falling during daily activities. Altering the step width is thus proposed as a simple and non-invasive treatment method in clinical practice.
... Increasing step cadence with a proportional reduction in the stride length at a constant speed has reduced foot inclination angles and impact forces by 5.6% [39] which decreases the number of initial contacts by hindfoot [40]. Besides, altering step width has reduced foot pronation [41,42]. Forefoot strike training has also demonstrated promising results in increasing foot arch [43][44][45]. ...
... The main literature search yielded a total of 4562 from which 1702 items remained after duplicate removal. A total of 1688 studies were excluded due to not meeting the inclusion criteria and 15 were included after screening of titles and abstracts for further eligibility check [17,37,[41][42][43][44][45][50][51][52][53][54][55][56][57]. (Fig 1) shows the flow diagram, summarizing the selection process and the number of studies excluded at each stage. ...
... Table 2 summarizes the characteristics of the included studies. There were 12 cross-sectional studies [17,37,41,42,44,45,[50][51][52][53][54]57] and 3 RCTs [43,52,58] assessing the effects of gait retraining on foot pronation. ...
Foot pronation is a prevalent condition known to contribute to a range of lower extremity injuries. Numerous interventions have been employed to address this issue, many of which are expensive and necessitate specific facilities. Gait retraining has been suggested as a promising intervention for modifying foot pronation, offering the advantage of being accessible and independent of additional materials or specific time. We aimed to systematically review the literature on the effect of gait retraining on foot pronation. We searched four databases including PubMed, Web of Science, Scopus and Embase from their inception through 20 June 2023. The Downs and Black appraisal scale was applied to assess quality of included studies. Two reviewers screened studies to identify studies reporting the effect of different methods of gait-retraining on foot pronation. Outcomes of interest were rearfoot eversion, foot pronation, and foot arch. Two authors separately extracted data from included studies. Data of interest were study design, intervention, variable, sample size and sex, tools, age, height, weight, body mass index, running experience, and weekly distance of running. Mean differences and 95% confidence intervals (CI) were calculated with random effects model in RevMan version 5.4. Fifteen studies with a total of 295 participants were included. The results of the meta-analysis showed that changing step width does not have a significant effect on peak rearfoot eversion. The results of the meta-analysis showed that changing step width does not have a significant effect on peak rearfoot eversion. Results of single studies indicated that reducing foot progression angle (MD 2.1, 95% CI 0.62, 3.58), lateralizing COP (MD -3.3, 95% CI -4.88, -1.72) can effectively reduce foot pronation. Overall, this study suggests that gait retraining may be a promising intervention for reducing foot pronation; Most of the included studies demonstrated significant improvements in foot pronation following gait retraining. Changing center of pressure, foot progression angle and forefoot strike training appeared to yield more favorable outcomes. However, further research is needed to fully understand its effectiveness and long-term benefits.
... Previous studies have altered lower extremity biomechanics during running in healthy adults by altering their temporal spatial parameters [11]. For example, both a narrower step width [12] and decreased cadence [13] during running increased peak hip adduction angle in healthy runners. An increased peak hip adduction angle during running has been identified as a prospective risk factor for patellofemoral pain and iliotibial band syndromes in female runners [6,14]. ...
... To compare the risk of bias across studies, answers to Quality Assessment Tool questions were weighted. Questions to the tool answered with a 'Yes' were given a score of 1, while 'No', 'Not Applicable', 'Cannot Determine', and 'Not Reported' answers were given a score of 0. The total score for each study was used to classify the risk of bias as either low (10)(11)(12)(13)(14), moderate (5-9), or high (0-4). For item 12 of the quality assessment we assumed, unless indicated otherwise, that the raters in prospective studies were blinded to the injured status of runners as measurements were recorded prior to injury. ...
... However, more prospective evidence is required to determine if temporal spatial parameters during running are associated with overuse injury development. In cross-sectional studies, alterations of temporal spatial parameters during running, such as step width, stride length, and cadence also altered biomechanical risk factors for overuse injury in healthy runners [12,13,40,41]. Recent efforts to alter biomechanical risk factors for injury through modifying one temporal spatial parameter, cadence, using wearable technology have been successful in the short term. ...
Background
Temporal spatial parameters during running are measurable outside of clinical and laboratory environments using wearable technology. Data from wearable technology may be useful for injury prevention, however the association of temporal spatial parameters with overuse injury in runners remains unclear.
Objective
To identify the association between overuse injury and temporal spatial parameters during running.
Data Sources
Electronic databases were searched using keywords related to temporal spatial parameters, running, and overuse injury, and authors’ personal article collections through hand search.
Eligibility Criteria for Selecting Studies
Articles included in this systematic review contained original data, and analytically compared at least one temporal spatial parameter (e.g. cadence) between uninjured and retrospectively or prospectively injured groups of runners. Articles were excluded from this review if they did not meet these criteria or measured temporal spatial parameters via survey.
Study Appraisal and Synthesis Method
The internal validity of each article was assessed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Meta-analyses were conducted for temporal spatial parameters if data existed from at least three separate cohorts of the same prospective or retrospective design. Data were pooled and analyzed using an inverse variance fixed-effect model.
Results
Thirteen articles which tested a total of 24 temporal spatial parameters during running were included in the review. Meta-analyses were conducted on four temporal spatial parameters using data from eleven retrospective studies. Healthy runners and those with a history of overuse injury had a similar average stride time (mean difference: − 0.01 s, 95% CI − 0.02 to 0.01 s), contact time (mean difference: 0.00 s, 95% CI 0.00–0.01 s), cadence (mean difference: 0.3 steps per minute (spm), 95% CI − 1.8 to 2.5 spm), and stride length (mean difference 0.00 m, 95% CI − 0.04 to 0.05 m) during running.
Limitations
Data pooled for meta-analyses were limited to retrospective design studies. Studies included in the systematic review had low methodological consistency.
Conclusion
Based on pooled results from multiple studies, stride time, contact time, cadence, and stride length averages are not distinguishable between runners either with or without a history of overuse injury. More prospective studies are required to determine the association of temporal spatial parameters with overuse injury development in runners.
Systematic Review Registration Registry and Number
CRD42018112290.
... 25 Three studies 55 83 95 evaluated the biomechanical effects of cues to reduce impact loading variables at foot strike. Four studies [84][85][86][87] evaluated the biomechanical effects of altering step width, but none of these included symptomatic participants. Three studies evaluated the biomechanical effects of cues to alter proximal mechanics, 22 23 88 with two aiming to reduce hip adduction, 22 23 and one to increase forward trunk lean. ...
... Running retraining strategies including reducing overstride and increasing step rate, reducing impact loading variables and transitioning strike pattern towards a midfoot strike was advocated by most experts for medial tibial stress syndrome (table 2). Additional consideration to reducing hip adduction and increasing step width was also suggested, which limited to very limited evidence indicates may reduce peak rearfoot eversion; 84 87 rearfoot eversion and forefoot dorsiflexion excursion; 87 peak internal ankle inversion moment; 84 and tension, compression and shear stresses on the tibia 86 (see online supplementary file 7). ...
... (10) "The chronic group one-So those people who are coming in and giving you a three or four-year history of medial tibial stress syndrome … I'll use gait training reasonably early and reasonably constantly and I think, with some degree, success as well." (16) Increasing step rate-limited evidence indicates ↓ ankle dorsiflexion at midstance 68 and ↓ peak tibial acceleration (limited); 61 65 69 and very limited evidence indicates ↓ tibial contact forces 64 Cues to increase step width-limited evidence indicates ↓ peak rearfoot eversion; 84 87 and very limited evidence indicates ↓ peak internal ankle inversion moment, 84 ↓ anterior tension, posterior compression and medial compression of the tibia, 87 and ↓ shear stress on the anterior, posterior, medial and lateral tibia 87 Cues to reduce impact loading variables-limited evidence indicates ↓ peak tibial acceleration 55 83 95 *Retraining strategy part of successful case series intervention in this condition. IR, internal rotation; VALR, vertical average loading rate; VILR, vertical instantaneous loading rate; VIP, vertical impact peak. ...
Importance Running-related injuries are highly prevalent.
Objective Synthesise published evidence with international expert opinion on the use of running retraining when treating lower limb injuries.
Design Mixed methods.
Methods A systematic review of clinical and biomechanical findings related to running retraining interventions were synthesised and combined with semistructured interviews with 16 international experts covering clinical reasoning related to the implementation of running retraining.
Results Limited evidence supports the effectiveness of transition from rearfoot to forefoot or midfoot strike and increase step rate or altering proximal mechanics in individuals with anterior exertional lower leg pain; and visual and verbal feedback to reduce hip adduction in females with patellofemoral pain. Despite the paucity of clinical evidence, experts recommended running retraining for: iliotibial band syndrome; plantar fasciopathy (fasciitis); Achilles, patellar, proximal hamstring and gluteal tendinopathy; calf pain; and medial tibial stress syndrome. Tailoring approaches to each injury and individual was recommended to optimise outcomes. Substantial evidence exists for the immediate biomechanical effects of running retraining interventions (46 studies), including evaluation of step rate and strike pattern manipulation, strategies to alter proximal kinematics and cues to reduce impact loading variables.
Summary and relevance Our synthesis of published evidence related to clinical outcomes and biomechanical effects with expert opinion indicates running retraining warrants consideration in the treatment of lower limb injuries in clinical practice.
... Typical step width during running is approximately 3 to 6 cm 1,3,20,25 and does not seem to differ between habitual foot strike groups. 20 A narrower step causes greater iliotibial band (ITB) strain and strain rate, 25 increased frontal plane ankle and knee moments, 3 and increased peak rearfoot eversion and hip adduction angles. 3 Greater hip adduction and knee internal rotation have been retrospectively and prospectively found in runners with ITB syndrome and patellofemoral pain syndrome, 12,29,30,35 and peak hip adduction and rearfoot eversion are greater in females with a history of tibial stress fractures. ...
... 20 A narrower step causes greater iliotibial band (ITB) strain and strain rate, 25 increased frontal plane ankle and knee moments, 3 and increased peak rearfoot eversion and hip adduction angles. 3 Greater hip adduction and knee internal rotation have been retrospectively and prospectively found in runners with ITB syndrome and patellofemoral pain syndrome, 12,29,30,35 and peak hip adduction and rearfoot eversion are greater in females with a history of tibial stress fractures. 28 Heiderscheit et al 18 noted that peak hip adduction angle decreased as step rate increased, which may suggest that runners concomitantly widened 5-in-5 their step width as they shortened their stride, but this has yet to be assessed. ...
... 27,31,32 All articles mentioned thus far reported neutral or positive changes in oxygen consumption, kinematics, and kinetics while shortening or widening the stride. However, all of these studies have looked only at habitual rearfoot, 8,9,18,19,27,32 did not state the foot strike pattern used by runners, 1,3,11,22,26 or did not differentiate between foot strike style groups. 25 These variables should be investigated in FFS, especially with a recent interest in minimalist shoes and barefoot running, which generally encourage the use of a FFS. ...
Some frontal plane and transverse plane variables have been associated with running injury, but it is not known if they differ with foot strike style or as stride length is shortened.
To identify if step width, iliotibial band strain and strain rate, positive and negative free moment, pelvic drop, hip adduction, knee internal rotation, and rearfoot eversion differ between habitual rearfoot and habitual mid-/forefoot strikers when running with both a rearfoot strike (RFS) and a mid-/forefoot strike (FFS) at 3 stride lengths.
Controlled laboratory study.
A total of 42 healthy runners (21 habitual rearfoot, 21 habitual mid-/forefoot) ran overground at 3.35 m/s with both a RFS and a FFS at their preferred stride lengths and 5% and 10% shorter.
Variables did not differ between habitual groups. Step width was 1.5 cm narrower for FFS, widening to 0.8 cm as stride length shortened. Iliotibial band strain and strain rate did not differ between foot strikes but decreased as stride length shortened (0.3% and 1.8%/s, respectively). Pelvic drop was reduced 0.7° for FFS compared with RFS, and both pelvic drop and hip adduction decreased as stride length shortened (0.8° and 1.5°, respectively). Peak knee internal rotation was not affected by foot strike or stride length. Peak rearfoot eversion was not different between foot strikes but decreased 0.6° as stride length shortened. Peak positive free moment (normalized to body weight [BW] and height [h]) was not affected by foot strike or stride length. Peak negative free moment was -0.0038 BW·m/h greater for FFS and decreased -0.0004 BW·m/h as stride length shortened.
The small decreases in most variables as stride length shortened were likely associated with the concomitant wider step width. RFS had slightly greater pelvic drop, while FFS had slightly narrower step width and greater negative free moment.
Shortening one's stride length may decrease or at least not increase propensity for running injuries based on the variables that we measured. One foot strike style does not appear universally better than the other; rather, different foot strike styles may predispose runners to different types of injuries.
© 2015 The Author(s).
... Running with a step width less than the preferred step width is associated with gait mechanics similar to those reported in people with tibial stress fracture (Brindle et al., 2013;McClay, 1995;Pohl et al., 2006;Williams and Ziff, 1991). For example, reduced step width during running has been linked to an increase in rearfoot pronation (Brindle et al., 2013;Pohl et al., 2006) and greater hip adduction and knee internal rotation (Brindle et al., 2013;Meardon et al., 2012). ...
... Running with a step width less than the preferred step width is associated with gait mechanics similar to those reported in people with tibial stress fracture (Brindle et al., 2013;McClay, 1995;Pohl et al., 2006;Williams and Ziff, 1991). For example, reduced step width during running has been linked to an increase in rearfoot pronation (Brindle et al., 2013;Pohl et al., 2006) and greater hip adduction and knee internal rotation (Brindle et al., 2013;Meardon et al., 2012). Pilot work from our lab also suggests that step width during running is negatively associated with the free moment, (Meardon and Derrick, 2008) frontal plane hip, and knee and ankle joint moments (Meardon and Derrick, 2011). ...
... Running with a step width less than the preferred step width is associated with gait mechanics similar to those reported in people with tibial stress fracture (Brindle et al., 2013;McClay, 1995;Pohl et al., 2006;Williams and Ziff, 1991). For example, reduced step width during running has been linked to an increase in rearfoot pronation (Brindle et al., 2013;Pohl et al., 2006) and greater hip adduction and knee internal rotation (Brindle et al., 2013;Meardon et al., 2012). Pilot work from our lab also suggests that step width during running is negatively associated with the free moment, (Meardon and Derrick, 2008) frontal plane hip, and knee and ankle joint moments (Meardon and Derrick, 2011). ...
... A narrow step width necessitates increased hip adduction by moving the foot medially relative to the body's center of mass. 3 By placing the foot medial to the midline of the body, the knee varus moment increases. 3 Elevated values of hip adduction and the knee varus moment increase strain of the iliotibial band, potentially contributing to the development of iliotibial band syndrome. ...
... A narrow step width necessitates increased hip adduction by moving the foot medially relative to the body's center of mass. 3 By placing the foot medial to the midline of the body, the knee varus moment increases. 3 Elevated values of hip adduction and the knee varus moment increase strain of the iliotibial band, potentially contributing to the development of iliotibial band syndrome. 18 Additionally, modulation of elevated knee varus moments may be an important consideration in runners with medial compartment osteoarthritis. ...
... Crossover mechanics also necessitates increased rearfoot eversion to achieve a plantigrade foot. 3,25 As rearfoot eversion increases, so does tibial internal rotation (r2=0.84), 25 leading to an increase in torsional loading of the tibia. 17 Bone is weakest under torsional loading. ...
Pathological mechanics are thought to play a role in many common running injuries. A review of the biomechanical literature reveals that a given running injury may be associated with multiple faulty running mechanics. Traditional rehabilitation programs have focused their efforts on addressing the injured anatomical structure. By focusing rehabilitation programs on correcting the pathomechanics of an injury, outcomes may be improved. Since the underlying faulty mechanics have been addressed, risk of reinjury may also be decreased. In this article, a pathomechanical paradigm for the treatment of the injured runner is introduced. Emphasis is placed on recognizing the most common types of faulty running mechanics often encountered in the clinical setting and their implications for injury. Finally, suggested treatment techniques are described.
... It has been observed that an increased step width can lead to decreased hip adduction angle and heel roll or peak knee inversion. Conversely, an increased peak hip adduction angle may be one of the factors that causes patellofemoral pain [12]. In addition, it has been shown that an increased stride frequency can significantly reduce stress on the knee and hip joints, which can result in a lower risk of running injuries [11]. ...
... It has been observed that an increased step width can lead to a decreased hip adduction angle and heel roll or peak knee inversion. Conversely, an increased peak hip adduction angle may be one of the factors that causes patellofemoral pain [12]. In addition, it has been shown that an increased stride frequency can significantly reduce stress on the knee and hip joints, which can result in a lower risk of running injuries [11]. ...
Background:Running is one of the simplest and most popular forms of exercise. Biomechanical evaluation of running is one of the elements of evaluating running technique and, consequently, improving sports performance. Running uphill and downhill is one of the components of daily running but also an element of training used by recreational runners. The aim of this study is to optimize running training and minimize the risk of injury by identifying changes in the spatiotemporal structure of running at different inclinations. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The protocol has been registered on the international platform INPLASY under the number INPLASY202430094U2. The search was conducted up to 30 March 2024 using the Scopus, PubMed, and Web of Science databases. Results: Spatiotemporal parameters were most frequently analyzed at 2.8–3.35 m/s velocities and inclinations in the range of −11% to 11%. Decreases in stride length (SL) and flight time (FT), and increases in step frequency (SF) were the most frequently reported changes from all parameters analyzed as a function of inclination and velocity. Significant increases or decreases in individual parameters were more often observed for positive inclination values than negative ones. Conclusions: The heterogeneous results of the study limit the possibility of determining the changes that occur in the spatiotemporal structure of the run under the impact of different inclinations. The variation in the results for negative inclination values indicates the different characteristics of running uphill and downhill. However, for uphill running, SF, SL, and FT are closely related to the increase in inclination.
... Modifying the BOG has been suggested as a strategy for altering lower extremity tissue loads and potentially reducing the risk of specific injuries such as tibial stress injuries. 7 A change in BOG will necessitate changes in lower extremity kinematics, reflecting an inherent interdependence. However, one's BOG may be partially determined by nonmodifiable factors such as skeletal anthropometry. ...
... A small sample size (15 males, 15 females), running speed of 3.5 mÁs À1 , and differences in calculating step width and BOG may explain the varied results compared with our current study. 7 We studied a more robust dataset of 93 males and 73 females across a wide range of running speeds and clearly demonstrated a more narrow BOG in males than in females at running speeds of 3.80 mÁs À1 and faster. Although step width and BOG in the 2 investigations cannot be directly compared, the general directions and relationships may still hold. ...
Context
A narrow base of gait (BOG), the mediolateral distance between the foot and body's line of gravity at midstance, during running is a suggested cause of injuries such as iliotibial band syndrome and tibial stress injury. However, an understanding of modifiable and nonmodifiable factors that influence BOG is lacking, which limits the development of corrective strategies.
Objective
To determine if BOG varies by sex and running speed and the influence of running kinematics and anthropometrics on BOG.
Design
Cross-sectional study.
Setting
Record review of routinely collected performance data from a National Collegiate Athletic Association Division I intercollegiate athletic program.
Patients or Other Participants
A total of 166 Division I collegiate athletes (basketball, cross-country, football, soccer).
Main Outcome Measure(s)
Running biomechanics (N = 166) and dual-energy x-ray absorptiometry-derived anthropometric data (n = 68) were extracted. Running variables were BOG, step rate, stride length, foot-inclination angle, center-of-mass vertical displacement, heel-to-center of mass anteroposterior distance, and peak stance-phase angles: hip flexion, hip adduction, pelvic drop, knee flexion, and ankle dorsiflexion. Extracted anthropometric variables were height; leg, femur, and tibia length; and anterior-superior iliac spine, hip-joint, and greater trochanter width. We calculated linear mixed-effects models to assess the influence of sex and running speed on BOG and identify the kinematic and anthropometric variables most associated with BOG.
Results
A significant interaction between sex and running speed on BOG was observed, with males demonstrating a smaller BOG than females at faster speeds and BOG decreasing overall with speed. The kinematic measures most associated with BOG at preferred running speed were foot-inclination angle at initial contact and peak stance-phase hip adduction and ankle dorsiflexion. Anterior-superior iliac spine width was the anthropometric variable most associated with BOG at preferred running speed.
Conclusions
Sex and running speed must be considered when determining the appropriateness of an individual's BOG. Additionally, BOG was associated with several potentially modifiable kinematic parameters.
... In order to produce a laterally directed GRF the horse must either position the limb more medially during stance, so that the COM provides a lateral directed GRF, and/or medial-lateral hoof wall height may alter the COP origin under the hoof, which would influence the GRF vector direction [27]. Medial hindlimb foot placement could be achieved by adducting the limb further under the body [39], or by the hindquarters rotating in yaw medially prior to stance, due to unbalanced dorsal plane moments. In humans narrower step width is associated with increased medio-lateral force production, increased pronation, greater hip adduction, greater knee internal rotation and increased tibial stress [39,40]. ...
... Medial hindlimb foot placement could be achieved by adducting the limb further under the body [39], or by the hindquarters rotating in yaw medially prior to stance, due to unbalanced dorsal plane moments. In humans narrower step width is associated with increased medio-lateral force production, increased pronation, greater hip adduction, greater knee internal rotation and increased tibial stress [39,40]. In an equine model of the spine, increasing stiffness along two thirds of the spine increased lateral and dorsoventral peak torques at the next joint to the stiffened spine [41]. ...
Asymmetry in forelimb dorsal hoof wall angles, termed unevenness, is associated with forelimb gait asymmetries, but compensatory mechanisms and out of plane ground reaction forces (GRFs) due to unevenness have yet to be documented. The aim of this study was therefore to investigate the effects of fore hoof unevenness on contralateral fore and hind limb force vectors patterns, in both sagittal and frontal planes. A group of n = 34 riding horses were classified into four groups: hoof angle difference of more than 1.5 degrees (UNEVEN; n = 27), including higher left fore (HIGH-LF; n = 12), higher right fore (HIGH-RF; n = 15), and hoof angle difference of less than 1.5 degrees (EVEN; n = 7). Three dimensional ground reaction forces GRFs were collected during trotting. GRF summary vectors representing the magnitude (VecMag) and angular direction (VecAng) of the entire stance phase in the sagittal and the frontal plane were calculated. The effects of unevenness on GRF production were explored using linear regression, repeated measures ANOVA and statistical parametric mapping (SPM) with significance at (P<0.05). In all uneven groups, increasing unevenness affected sagittal VecAng values in the forelimbs, with more propulsive GRF in the high hoof. In the HIGH-RF group, medial GRFs were also found in the high RF hoof compared to lateral GRFs in the low LF hoof (RF VecAng: 0.97±1.64 (deg); LF VecAng: -0.64±1.19 (deg); P<0.05). In both HIGH groups, compensatory associations to increasing unevenness were only found in the RH, but also a significantly greater lateral VecAng was found in the LH (P<0.05) compared to the RH limb. No significant differences (P>0.05) were found between hindlimb pairs in the EVEN group. Unbalanced sagittal and increased frontal plane GRFs in uneven horses suggest that they have greater locomotory challenges, as the equine musculoskeletal system is not constructed to withstand movement and loading in the frontal plane as effectively as it is in the sagittal plane.
... Our results indicated that during LR, sagittal plane ankle-knee coordination exhibited a proximal pattern (71°) with wider step width, compared to normal walking. This shift potentially changes gait stability and efficiency [31]. A potential explanation for this shift is that a wider stance may lengthen the mediolateral moment arm between the body center of mass and center of pressure [32], requiring different muscle activation for balance and propulsion [33]. ...
Flat foot is a common condition marked by the collapse of the medial longitudinal arch, leading to altered lower limb biomechanics and increased risk of musculoskeletal injuries. We aimed to investigate if wide step width changes the lower limb inter-joint coordination and its variability in flat feet individuals. Twenty flat-footed individuals participated in this cross-sectional study. Lower limb kinematics were assessed by 3-dimensional motion analysis during walking and running on a treadmill with preferred and wide step widths while receiving visual feedback. Inter-joint coordination was quantified using vector-coding for joint angles in the hip, knee, and ankle. Wide walking showed a shift towards proximal joint motion in sagittal ankle-knee coordination during loading response during LR (p=0.006), an In-phase motion in transverse ankle-hip coordination during push-off (p=0.004), and an In-phase pattern in frontal knee-hip coordination during mid-stance (p=0.027). Frontal ankle and transverse knee coordination during push-off changed to In-phase (p=0.003). Wide running significantly shifted frontal ankle-hip coordination towards proximal joint motion during mid-stance (p=0.05). Transverse ankle-hip coordination showed an in-phase pattern in wide conditions during push-off (p=0.044), during LR (p=0.022). Wide walking, significantly increased coordination variability of the sagittal ankle-knee during LR and decreased transverse ankle-hip during push-off. Wide walking significantly increased coordination variability in ankle-knee in sagittal plane during LR (p<0.001). Wide running significantly decreased the coordination variability in the ankle-knee sagittal during LR (p<0.001) and knee-hip sagittal during LR (p=0.007) and push-off (p=0.016). The results showed that wide step width can affect inter-joint coordination during walking/running in flat-footed individuals at certain points. These results should be considered when using a wide step width as a gait retraining method for managing flat-footed individuals.
... This phenomenon was also highlighted in previous studies on unilateral TFAs during running and was suggested to be due to compensatory strategies adopted by this population 9,10,22 . Having a sufficiently high vertical GRI is essential to create sufficient aerial time to reposition the limbs in air to prepare for the next step 19,23,24 . In a study comparing faster and slower able-bodied runners 23 , similar vertical GRIs were achieved despite speed differences. ...
The mediolateral ground reaction force (M-L GRF) profile that realizes a symmetrical mediolateral ground reaction impulse (M-L GRI) between both limbs is essential for maintaining a straight movement path. We aimed to examine the M-L GRF production across different running speeds in unilateral transfemoral amputees (TFA) to identify strategies for maintaining straight running. The average medial and lateral GRF, contact time (tc), M-L GRI, step width, and center of pressure angle (COPANG) were analyzed. Nine TFAs performed running trials at 100% speed on an instrumented treadmill. Trials were set at 30–80% speed with an increment of 10%. Seven steps from the unaffected and affected limbs were analyzed. Overall, the unaffected limbs exhibited a higher average medial GRF than the affected limbs. The M-L GRI were similar between both limbs at all speeds, implying that the participants were able to maintain a straight running path. The affected limb exhibited a longer tc and a lower M-L GRF profile than the unaffected limb. The results showed that unilateral TFAs adopted limb-specific strategies to maintain a straight running path, and that these limb-specific strategies were consistent across different running speeds.
... Deliberate directed increases in step width to complement faster cadence, reductions in hip adduction angle, rearfoot eversion angle, knee abduction moment and impulse, and rearfoot inversion moment occur (43). ...
Healthy running form is characterized by motion that minimizes mechanical musculoskeletal injury risks and improves coactivation of muscles that can buffer impact loading and reduce stresses related to chronic musculoskeletal pain. The American College of Sports Medicine Consumer Outreach Committee recently launched an infographic that describes several healthy habits for the general distance runner. This review provides the supporting evidence, expected acute motion changes with use, and practical considerations for clinical use in patient cases. Healthy habits include: taking short, quick, and soft steps; abdominal bracing; elevating cadence; linearizing arm swing; controlling forward trunk lean, and; avoiding running through fatigue. Introduction of these habits can be done sequentially one at a time to build on form, or more than one over time. Adoption can be supported by various feedback forms and cueing. These habits are most successful against injury when coupled with regular dynamic strengthening of the kinetic chain, adequate recovery with training, and appropriate shoe wear.
... 74 Understanding the underlying knee biomechanics during simple tasks is imperative. Previous work in this area has evaluated the sex-and/or age-based differences in knee kinematics/kinetics of running, [75][76][77][78][79] jumping tasks, [80][81][82][83][84][85] and cutting maneuvers 80,86,87 in children, adolescents, and young adults. Multiple other tasks have been evaluated biomechanically in adolescents using 3DMA including tasks involved in movement screening 88 ; directional changes/run-and-cut tasks [89][90][91][92][93] ; drop-landing or vertical jump tasks 88,89,[94][95][96][97][98][99] ; and sport-specific tasks including soccer kicks, 100 baseball/softball, 101-105 gymnastics, 106 tennis, 107,108 volleyball, 99 and cricket. ...
Three-dimensional motion capture systems may improve evaluation, treatment, and rehabilitation of knee injuries, because quantitative assessment of the knee improves understanding of biomechanical mechanisms. The benefit of using motion analysis in pediatric sports medicine is that it allows closer and more focused evaluation of sports injuries using kinematics, kinetics, and electromyogram with physical and imaging to determine what is happening dynamically during sports. Future research investigating knee injuries should focus on identifying risk factors, assessing the effectiveness of surgical and nonsurgical interventions, and developing return to sport/rehabilitation protocols. The literature is focused on motion capture in adults with knee injuries.
... The modulation of step width also affects the running biomechanics. According to Brindle, et al. [47], increasing the width from narrow to broad has a significant effect on lower extremity biomechanics, decreasing the peak hip adduction angle, peak knee abduction moment, knee abduction impulse, and peak rearfoot eversion angle. Hence, the angular configuration is modified based on the interaction of end-effectors with the ground that generates the spatiotemporal parameters. ...
We investigated the effect of prolonged running on joint kinematics and its association with stride complexity between novice and elite runners. Ten elite marathoners and eleven healthy individuals took part in a 20 min submaximal prolonged running experiment at their preferred running speed (PRS). A three-dimensional motion capture system was utilized to capture and calculate the alpha exponent, stride-to-stride fluctuations (SSFs), and stride-to-stride variability (SSV) of spatiotemporal parameters and joint kinematics. In the results, the elite athletes ran at a considerably higher PRS than the novice runners, yet no significant differences were found in respiratory exchange ratio with increasing time intervals. For the spatiotemporal parameters, we observed a significant increase in the step width and length variability in novice runners with increasing time-interval (p < 0.05). However, we did not observe any differences in the alpha exponent of spatiotemporal parameters. Significant differences in SSF of joint kinematics were observed, particularly in the sagittal plane for ankle, knee, and hip at heel strike (p < 0.05). While in mid-stance, time-interval differences were observed in novices who ran with a lower knee flexion angle (p < 0.05). During toe-off, significantly higher SSV was observed, particularly in the hip and ankle for novices (p < 0.05). The correlation analysis of joint SSV revealed a distinct negative relationship with the alpha exponent of step-length and step-width for elite runners, while, for novices, a positive relation was observed only for the alpha exponent of step-width. In conclusion, our study shows that increased step-width variability seen in novices could be a compensatory mechanism to maintain performance and mitigate the loss of stability. On the other hand, elite runners showed a training-induced effective modulation of lower-limb kinematics to improve their running performance.
... There are several other mechanisms linked with reductions in frontal plane hip/knee loading: increased step widths, trunk sway, and gluteus medius strength [59][60][61][62]. Increased step width has been previously found in children with ASD [17]. ...
... There are several other mechanisms linked with reductions in frontal plane hip/knee loading: increased step widths, trunk sway, and gluteus medius strength [59][60][61][62]. Increased step width has been previously found in children with ASD [17]. ...
Research examining gait biomechanics of persons with autism spectrum disorder (ASD) has grown significantly in recent years and has demonstrated that persons with ASD walk at slower self-selected speeds and with shorter strides, wider step widths, and reduced lower extremity range of motion and moments compared to neurotypical controls. In contrast to walking, running has yet to be examined in persons with ASD. The purpose of this study was to examine lower extremity running biomechanics in adolescents (13-18-year-olds) with ASD and matched (age, sex, and body mass index) neurotypical controls. Three-dimensional kinematics and ground reaction forces (GRF) were recorded while participants ran at two matched speeds: self-selected speed of adolescents with ASD and at 3.0m/s. Sagittal and frontal plane lower extremity biomechanics and vertical GRFs were compared using two-way ANOVAs via statistical parametric mapping. Adolescents with ASD ran with reduced stride length at self-selected speed and reduced vertical displacement, loading-propulsion GRFs, propulsion plantarflexion moments, loading-propulsion hip abduction moments, and loading knee abduction moments at both speeds. Running at 3.0m/s increased sagittal plane hip and knee moments surrounding initial contact and frontal plane knee angles during mid stance and propulsion compared to self-selected speeds. Reduced contributions from primarily the ankle plantarflexion but also knee abduction and hip abduction moments likely reduced the vertical GRF and displacement. As differences favored reduced loading, youth with ASD can safely be encouraged to engage in running as a physical activity.
... Currently, there is limited research on elliptical trainer modifications to alter lower limb biomechanics, but modifications in gait have been extensively examined to reduce lower limb injury risk Brindle et al., 2014;Yocum et al., 2018). A common gait modification is increasing step width to reduce the frontal plane knee joint loading for people at risk or with medial compartment knee osteoarthritis (OA). ...
Elliptical trainers that increase the inter-pedal distance may have potential benefits for knee osteoarthritis by decreasing the amount of knee varus. Modifying elliptical trainers with a converging footpath and reduced inter-pedal distance may be beneficial for reducing anterior knee pathology risk by decreasing knee valgus angles. Twenty-one college students participated in a single testing session. Participants exercised on two different elliptical trainers, one modified with a converging footpath and reduced inter-pedal width, and a standard elliptical trainer. Participants exercised for 2 min at three ramps incline at 120 strides per minute and constant work rate. Three-dimensional kinematics and electromyography of the dominant lower limb were recorded. Multiple 2 × 3 (Elliptical x Incline) ANOVAs with Bonferroni corrections were used to compare the two elliptical trainers at each incline for kinematics and muscle activity. The modified elliptical trainer displayed significantly decreased peak knee valgus (p = 0.031, η2p=0.234), peak knee flexion (p = 0.006, η2p=0.246), and interactions for peak knee flexion (p = 0.001, η2p=0.250) and vastus lateralis (p < 0.01, η2p=0.380) muscle activity compared to the standard elliptical trainer. The decreased peak knee valgus and flexion angles could be beneficial for reducing long-term injury risk for anterior knee pathologies.
... 11 Previous authors also have suggested that the main biomechanical factors that may put a runner at increased risk for iliotibial band syndrome (ITBS) are excessive hip adduction and internal rotation, and knee internal rotation and abduction during the stance phase. [12][13][14][15] Clinically, GMED dysfunction has been implicated in numerous musculoskeletal disorders including low back pain, patellofemoral pain syndrome (PFPS) and other lower limb injuries. 6,7,10 Maximizing hip muscle recruitment during rehabilitation exercises may increase treatment efficacy, improve lower limb kinematics, assist in injury prevention, improve athletic performance and result in decreased pain. ...
Background:
Increased hip adduction and internal rotation during the early stance phase of running have been linked to an increased risk of lower extremity injury. Both the gluteus maximus (GMAX) and gluteus medius (GMED) eccentrically control these motions. GMAX and GMED activation levels during commonly used rehabilitation exercises requires further exploration.
Hypothesis/purpose:
The purpose of this study was to compare peak surface electromyography (sEMG) amplitudes of GMAX and GMED between three closed-chain rehabilitation exercises: bilateral hip external rotation with resistance band (BER), forward lunge with resistance band (FL), and single-leg rotational squat (SLS). It was hypothesized that the FL would elicit greater peak amplitude in the GMAX and GMED than SLS and BER.
Study design:
Descriptive, observational cohort study.
Methods:
Twenty-two healthy runners (14 male, 8 female) had sEMG electrodes placed bilaterally on GMAX and GMED. Participants completed three repetitions each of BER, FL, and SLS exercises with sEMG data normalized to the maximal amplitude recorded at each muscle during the running trial (% MRC). Seven inertial measurement units affixed to the lower extremity measured joint kinematics to enable the exercises to be split into eccentric and concentric phases respectively.
Results:
There were no significant differences between exercises during the eccentric phases with all peak amplitudes for GMAX and GMED being less than < 30% MRC. Both the SLS (GMAX: 48.2 ± 45.2% MRC, p = 0.019; GMED: 39.3 ± 24.8% MRC, p < .001) and FL (GMAX: 65.8 ± 58.9% MRC, p < .001; GMED: 52.2 ± 34.9% MRC, p<.001) elicited significantly greater peak amplitudes than BER (GMAX: 21.7 ± 22.3% MRC; GMED: 22.8 ± 21.2% MRC) during the concentric phase.
Conclusion:
Running related injuries have been linked to deficits in GMAX and GMED activation and strength. When averaged bilaterally across 22 healthy runners, peak GMAX and GMED amplitudes during three weight bearing exercises were less than 70% MRC. All three exercises had comparable eccentric peak amplitudes; however, the BER exercise produced a significantly reduced GMAX and GMED amplitude during the concentric phase versus the FL and SLS. The FL and SLS appear equally effective at eliciting peak GMAX and GMED activation.
Level of evidence:
3.
... There is some evidence to support the idea that landing with a narrow step width (feet closer together) is more economical. 15,16 However, it has also been proposed that greater foot and pelvic control are needed (especially within the frontal and transvers planes) with this style potentially contributing to iliotibial band and anterior tibialis pathologies as well as increased rotational forces on the tibia. 17 While these are certainly valid points, it may be that a narrower trail/step width combined with overstriding results in increased stress to these areas. ...
... For example, obese runners had 15.4% less vertical excursion of the COM and 19.4% wider step widths than nonobese runners. Narrow step width increases risk for onset of tibial stress fractures, hip adduction, knee abduction moment, and ankle inversion injury 31,32 ; thus, wider steps may attenuate injury risk. Other studies have shown that vertical oscillation of the COM is related to VALR values and peak GRF, where less oscillation (vertical excursion) is related to lower loading values. ...
Objective:
Some recreational runners with obesity successfully train or compete without musculoskeletal injury. Insight into the key kinetic strategies of injury-free heavier runners is necessary to appropriately guide development of safe training programs for this population. This study determined key biomechanical strategies of running in individuals with body mass index (BMI) values above and below 30kg/m2 .
Design:
This was a case control study of runners with obesity (n=18; 42.7 years, 38.9% women) who were matched by sex, age, footstrike type, footwear characteristics, and running speed with healthy runners (n=77; 41.7 years, 32.5% women).
Setting:
Research laboratory affiliated with an academic medical center.
Main outcome measures:
A seven-camera optical motion analysis system was used to capture running kinematics and an instrumented treadmill captured kinetic data. Main outcomes were temporal spatial parameters, joint excursions, peak ground reaction forces (GRF), joint moments, vertical average loading rate (VALR), impulses and vertical stiffness (Kvert ).
Results:
Runners with obesity demonstrated 15% less vertical excursion of the center of mass, 18% wider strides and 3% longer stance times than non-obese runners (p<0.05). Normalized peak GRFs and VALRs were higher in the non-obese group. Absolute GRF impulse was higher in the group with obesity compared to the non-obese group (339.6 ± 55.2 Ns versus 255.0 ± 45.8 Ns; p=0.0001). Kvert was higher in the obese group compared to the non-obese group (238.6 ± 50.3 N/cm versus 183.1 ± 29.4 N/cm; p=0.0001). Peak hip moments were higher in runners with obesity in sagittal and frontal planes (p<0.05) CONCLUSION: Runners with obesity dampened impact forces and controlled loading rate more than non-obese runners by increasing lower body stiffness and constraining vertical displacement. This article is protected by copyright. All rights reserved.
... For example, the initial shock provoked by foot-ground collision during running can be modified by initial contact foot-strike pattern (rearfoot or forefoot) [19]. Some authors observed an influence of crossover gait and level of foot protonation on the mediolateral component of the GRF [21][22][23][24]. Other factors that are supposed to influence trunk stability during gait are gender and level of training, but studies exist only with regard to lower trunk level or walking gait [11,24]. ...
Upper trunk (UT) kinematics in runners and its relationship with lower limbs has been poorly investigated, although it is acknowledged that dynamic stability of the upper body is a primary objective of human locomotion. This study aimed to explore UT kinematics according to gender and level of training and in relation to lower limb run patterns described through the presence of: overstriding, crossover, excessive protonation, and pelvic drop. Lower body variables chosen to describe running pattern were those that are frequently modified during gait-retraining with the goal of reducing injury risk. Eighty-seven recreational runners (28 females and 59 males, age 41 ± 10 years) performed a one minute run test on a treadmill at self-selected speed. UT kinematics was measured using an inertial measurement unit, while run features were assessed through an optoelectronic system and video analysis. Accelerations and root-mean-square on mediolateral and anteroposterior axes, normalized using the vertical component of the acceleration, were estimated to describe UT stability. Results showed no significant differences in the normalized UT acceleration root-mean-square according to gender and level of training as well as according to the presence of overstriding, crossover, and excessive protonation. The only running strategy studied in this work that showed a significant relationship with UT stability was the presence of excessive pelvic drop. The latter was significantly associated (p=0.020) to a decrease in the normalized acceleration root-mean-square along the mediolateral direction. Although the excessive pelvic drop seemed to have a positive effect in stabilizing the upper body, concerns remain on the effect of a poor control of the pelvis on the biomechanics of lower limbs. Results obtained confirm the hypothesis that the lower body is able to respond to varying impact load conditions to maintain UT stability.
... Step width was also significantly increased with TL, which is noteworthy as increased step width has been a successful intervention to reduce KAM (Brindle et al., 2014;Paquette et al., 2015;Richards et al., 2018). The combination of lateralized GRF vector, a more medial hip joint, and increased step width likely contribute to the large reduction in hip abduction moment with TL. ...
First peak knee abduction moment (KAM) has been associated with the severity and progression of knee osteoarthritis (KOA). Gait modifications, including lateral trunk lean (TL), medial knee thrust (MKT), and reduced foot progression (FP) have decreased KAM. However, their effects on the hip joint are poorly understood. Reduced hip abduction moment has been found to be predictive of KOA progression and has been hypothesized to represent a decreased demand on the hip musculature. Lack of studies investigating changes in hip mechanics as a result of gait modification limits our understanding of their cumulative benefit, therefore, we investigated the effects of TL, MKT, and FP on internal hip abduction moment as well as rate change in net joint reaction force. Using real-time visual biofeedback, five trials were completed for each modification. Each modification target range was individualized to 3-5 SD greater (TL and FP) or lesser (MKT) than the participants mean baseline value. Kinematics and kinetics at the hip and knee were calculated at first peak KAM. Trunk lean and MKT decreased hip abduction moment compared to baseline (p < 0.001). Trunk lean increased rate change in net joint reaction force at both the hip (p < 0.001) and knee (p < 0.001) compared to baseline. Additional research is needed to fully understand the effect of gait modifications in a clinical population, particularly the relationship between hip abduction moments and KOA progression. Although interventions such as MKT and TL can be successful in reducing KAM, their effects on hip abduction moment should be considered before clinical implementation.
... Many biomechanical studies have used inverse kinematics and inverse dynamics approaches to study how differences observed in experimental joint angles, joint torques, and muscle activations can elucidate the clinical or biomechanical questions of human locomotion [10], [11]. The inverse method is however not sufficient for predicting new movements where the experimental recording is not available or when either the model or the neural control strategy changes during the experiment. ...
Many activities of daily living require a high level of neuromuscular coordination and balance control to avoid falls. Complex musculoskeletal models paired with detailed neuromuscular simulations complement experimental studies and uncover principles of coordinated and uncoordinated movements. Here, we created a closed-loop forward dynamic simulation framework that utilizes a detailed musculoskeletal model (19 degrees of freedom, and 92 Muscles) to synthesize human balance responses after support-surface perturbation. In addition, surrogate response models of task-level experimental kinematics from two healthy subjects were provided as inputs to our closedloop simulations to inform the design of the task-level controller. The predicted muscle EMGs and the resulting synthesized subject joint angles showed good conformity with the average of experimental trials. The simulated whole-body center of mass displacements, generated from a single kinematics trial per perturbation direction, were on average, within 7 mm (anterior perturbations) and 13 mm (posterior perturbations) of experimental displacements. Our results confirmed how a complex subject-specific movement can be reconstructed by sequencing and prioritizing multiple task-level commands to achieve desired movements. By combining the multidisciplinary approaches of robotics and biomechanics, the platform demonstrated here offers great potential for studying human movement control and subject-specific outcome prediction. IEEE
... In addition to these variables, the step width (SW) defines the mediolateral distance between 2 consecutive steps during running. For experienced runners, the SW during natural running (3.5-4 m/s) ranges from 0.02 to 0.06 m [1,10,11,15]. In contrast, SW during sprinting is relatively wide, as SW values of elite and national level sprinters decrease from 0.39 m at the initial step to 0.17 m in the maximal speed phase during accelerated sprinting [7]. ...
This study aimed to describe changes in step width (SW) during accelerated sprinting, and to clarify the relationship of SW with sprinting performance and ground reaction forces. 17 male athletes performed maximal-effort 60 m sprints. The SW and other spatiotemporal variables, as well as ground reaction impulses, over a 52 m distance were calculated. Average values for each 4 steps during acceleration were calculated to examine relationships among variables in different sections. The SW rapidly decreased up to the 13th step and slightly afterward during accelerated sprinting, showing a bilinear phase profile. The ratio of SW to the stature was significantly correlated with running speed based on average values over the 52 m distance and in the 9th-12th step section during accelerated sprinting. The SW ratio positively correlated with medial, lateral and mediolateral impulses in all step sections, except for medial impulse in the 17th-20th step section. These results indicate the importance of wider SW for better sprinting performance, especially in the 9th-12th step section. Moreover, the wider SW was associated with larger medial impulse and smaller lateral impulse, suggesting that a wide SW contributes to the production of greater mediolateral body velocity during accelerated sprinting.
... Increased step width has been observed among runners asked to run with a shorter step length, and this effect is particularly evident when utilising a forefoot strike pattern (Boyer & Derrick, 2015). A wider step width tends to reduce the internal knee abduction moment during running (Brindle, Milner, Zhang, & Fitzhugh, 2014), which would decrease the distribution of compression force onto the medial compartment in our model. Contrary to our hypothesis, foot strike pattern did not affect TFJ peak force, force impulse, or force impulse per kilometre. ...
The purpose of this study was to examine the effects of step length and foot strike pattern along with their interaction on tibiofemoral joint (TFJ) and medial compartment TFJ kinetics during running. Nineteen participants ran with a rear foot strike pattern at their preferred speed using a short (-10%), preferred, and long (+10%) step length. These step length conditions were then repeated using a forefoot strike pattern. Regardless of foot strike pattern, a 10% shorter step length resulted in decreased peak contact force, force impulse per step, force impulse per kilometre, and average loading rate at the TFJ and medial compartment, while a 10% increased step length had the opposite effects (all P < 0.05). A forefoot strike pattern significantly lowered TFJ and medial compartment TFJ average loading rates compared with a rear foot strike pattern (both <0.05) but did not change TFJ or medial compartment peak force, force impulse per step, or force impulse per km. The combination of a shorter step length and forefoot strike pattern produced the greatest reduction in peak medial compartment contact force (P < 0.05). Knowledge of these running modification effects may be relevant to the management or prevention of TFJ injury or pathology among runners.
... Our results supports previous research that narrow step width increases KAM. 26 Narrow step width was a unique characteristic of the female gait, although the reasons for this are unclear. Wider step width requires more power from the abductors, and on average, females have weaker abductor muscles and increased lever arm of body COM relative to males. ...
This study investigated sex differences in knee biomechanics and investigated determinants for difference in a geriatric population. Age-matched healthy volunteers (42 male and 42 female, average age 65 years) without knee OA were included in the study. Subjects underwent physical examination on their knee and standing full-limb radiography for anthropometric measurements. Linear, kinetic and kinematic parameters were compared using a three-dimensional, 12-camera motion capture system. Gait parameters were evaluated and determinants for sex difference were evaluated with multiple regression analysis. Females had a higher peak knee adduction moment (KAM) during gait (p = 0.004). Females had relatively wider pelvis and narrower step width (both p < 0.001). However, coronal knee alignment was not significantly different between the sexes. Multiple regression analysis revealed that coronal alignment (b = 0.014, p < 0.001), step width (b = -0.010, p = 0.011), and pelvic width/height ratio (b = 1.703, p = 0.046) were significant determinants of peak KAM. Because coronal alignment was not different between the sexes, narrow step width and high pelvic width/height ratio of female were the main contributors to higher peak KAM in females. Sex differences in knee biomechanics were present in the geriatric population. Increased mechanical loading on the female knee, which was associated with narrow step width and wide pelvis, may play an important role in future development and progression of OA. This article is protected by copyright. All rights reserved.
... A narrow base of support has been linked to tibial stress fractures, iliotibial band syndrome, and several kinematic patterns that have been associated with running injuries, such as excessive hip adduction and overpronation. [35][36][37] As such, this variable should be evaluated in all runners, and runners with a "cross-over sign" or "scissoring gait," characterized by an overly narrow base of support, may consider modification. ...
Running biomechanics play an important role in the development of injuries. Performing a running biomechanics analysis on injured runners can help to develop treatment strategies. This article provides a framework for a systematic video-based running biomechanics analysis plan based on the current evidence on running injuries, using 2-dimensional (2D) video and readily available tools. Fourteen measurements are proposed in this analysis plan from lateral and posterior video. Identifying simple 2D surrogates for 3D biomechanic variables of interest allows for widespread translation of best practices, and have the best opportunity to impact the highly prevalent problem of the injured runner.
... Retro-reflective markers were attached to the right lower extremity and pelvis on anatomical landmarks and thermoplastic shells (Brindle et al., 2014). Briefly, anatomical markers used to define joint centers were placed on the malleoli, first and fifth metatarsal heads, femoral epicondyles, greater trochanters, and iliac crests. ...
... However, due to an increasing number of recreational participants in distance running events this population is of growing interest. Recent research surrounding recreational runners has investigated step width alterations (Brindle, Milner, Zhang, & Fitzhugh, 2014), however there are no data, that the current authors are aware of, pertaining to stride rate, over a longitudinal period within this population. This study therefore aimed to investigate the stride rate dynamics, utilising a novel computational method, produced by a recreational runner when undertaking his first marathon. ...
The purpose of this study was to investigate stride rate (SR) dynamics of a recreational runner participating in his debut marathon. Tibial accelerometry data obtained during a half marathon (R1) and marathon (R2) were utilised. SR data were extracted utilising novel computational methods and descriptive statistics were utilised for analysis of R2, and comparison of the first half of the marathon (R2half) to R1. Results indicate that the participant employed comparable SR strategy in R1 and R2half. For R2 a combined decreasing trend in SR and increased variance in SR from 30 km (R2 =0.0238) was observed. Results indicate that the participant had the ability to maintain SR strategy for the first half of the marathon, however as fatigue onset occurred this ability decreased. Running strategies on SR during fatigue may be of future use to recreational runners.
Step width is a critical factor influencing lower limb biomechanics during running, significantly affecting stability, performance, and injury risk. Understanding these effects is essential for optimizing running performance and minimizing injury risk. This study evaluated the effects of varying step widths on lower limb biomechanics at different running speeds. Thirteen healthy Chinese males (aged 20–24) participated in the study, running at speeds of 3.0 m/s and 3.7 m/s using six distinct step widths: the preferred step width and five variations (reductions of 13% and 6.5%, and increases of 6.5%, 13%, and 25%, based on leg length). Data were collected using a motion capture system and force plates and analyzed through repeated measures ANOVA and correlation tests. The results indicated that wider step widths significantly reduced peak knee abduction moments and hip adduction angles, whereas narrower step widths increased knee joint loading. These findings have important implications for clinicians and runners, suggesting that careful step width selection can help reduce injury risk and enhance running efficiency. This study contributes a new dataset that lays the foundation for future research into the relationship between step width and running biomechanics and serves as a reference for training and rehabilitation practices.
Background: Knee osteoarthritis (KOA) is a prevalent musculoskeletal disease affecting joint mechanics. Considering the effect of step-width changes on the biomechanics of gait, especially the alteration of stability dynamics during narrow-base gait, this study investigated the kinematic parameters of the lower extremities during both normal and narrow-base walking in individuals with and without KOA.
Methods: A cross-sectional study with 20 individuals with bilateral KOA and 20 controls was conducted. Participants walked on a treadmill at a preferred speed across normal and narrow paths. Joint angles and angular velocities in the sagittal and frontal planes were recorded, and mixed ANOVA was used to analyze group × condition effects.
Results: Significant main effects of walking condition were observed for hip (p = 0.001) and ankle angles (p = 0.002) in the frontal plane, and knee (p = 0.004) and ankle angular velocities (p = 0.002) in the sagittal plane. Moreover, there were significant main effects of group on the hip (p = 0.01) and knee angles (p = 0.04) in the sagittal plane. KOA group showed higher peak hip adduction (p < 0.001) and ankle inversion (p = 0.02]) during narrow-base walking than on the normal path. People with KOA had also significantly higher peak angular velocity of knee flexion (p = 0.03), ankle dorsiflexion (p = 0.002), and ankle inversion (p = 0.03) during narrow-base walking.
Conclusions: The findings suggest that KOA and narrow-base gait challenges may trigger distinct kinematic adaptation strategies, potentially contributing to cartilage degeneration and altering balance mechanisms.
Keywords: Biomechanical Phenomena; Cross-Sectional Studies; Gait; Humans.
Background
Individuals with pronated feet often experience altered foot biomechanics, leading to increased risk of lower limb injuries. Step width modification has been proposed as a potential intervention to improve foot alignment during gait.
Research question
Does modifying step width influence rearfoot eversion and medial longitudinal arch angle (MLAA) in individuals with pronated feet during walking and running?
Methods
Twenty individuals with pronated feet underwent analysis during walking and running on treadmill, maintaining increased or decreased step width using real-time visual feedback. Three-dimensional motion analysis measured rearfoot eversion and MLAA during the stance phase of gait.
Results
Wide step width significantly reduced peak rearfoot eversion during waking (mean difference — with normal step width — (MD) = 3.6°, p < 0.001) and running (MD = 4.4°, p < 0.001), time to peak rearfoot eversion during walking (MD = 16.6 p < 0.001) and running (MD = 13.8°, p = 0.014), rearfoot eversion at touch down (TD) during walking (MD = 1.3°, p = 0.004), rearfoot eversion excursion during running (MD = 4.3°, p < 0.001), and peak MLAA during walking (MD = 2.9°, p = 0.006) and MLAA excursion during running (MD = 4.8°, p = 0.004).
By contrast, during running, narrow condition significantly increased peak rearfoot eversion (MD = 3.4°, p < 0.001). During walking, time to peak rearfoot eversion (MD = 16.1, p < 0.001), rearfoot eversion at TD (MD = 1.4°, p = 0.008), rearfoot eversion excursion (MD = 5.9°, p < 0.001), and peak MLAA (MD = 3.4°, p < 0.001) were significantly increased.
Significance
This study highlights the potential of step width modification as a simple yet effective intervention to improve foot biomechanics in pronated feet individuals during walking and running. Further research could lead to the development of personalized strategies for pronated feet individuals.
Introduction:
Lateral ankle sprains (LAS) frequently lead to residual soft tissue impairments, often attributed to biomechanical dysfunction during movement.
Objective:
The purpose of this study was to compare running biomechanics between adolescent runners with soft tissue pathologies following LAS (injured) and healthy runners (control), and between limbs.
Design:
Retrospective cohort study.
Setting:
Hospital-affiliated sports injury prevention center.
Participants:
Twenty-five adolescent runners with a history of LAS and current ankle impingement or tendinopathy (23F, 2M; age: 15±2 years; BMI: 19.5±2.5kg/m2 ; symptom duration: 1.1±0.9 years), and 20 healthy controls without any LAS history (19F, 4M; age: 15±1 years; BMI: 19.2±2.7kg/m2 ) were included in this study.
Interventions:
All participants completed a clinical gait assessment in which they ran at a self-selected speed on a force-plate instrumented treadmill, while two video cameras recorded 2-dimensional sagittal and coronal views.
Main outcome measures:
Foot rotation, step width, contact time, and cadence were compared between groups and limbs (involved, uninvolved [or "better" for bilateral cases]) using a multivariate analysis of variance (MANOVA). Rearfoot landing and foot strike type were compared between groups and limbs using a Chi-square analysis.
Results:
The injured group had significantly increased step width (F=4.71, p=0.04; Mean Difference with Standard Error [MDSE]: 1.5[0.7]cm) compared to controls. The injured groups' involved limb had longer contact time (F=4.62, p=0.03; MDgroup : 12[7]ms, MDlimb : 22[11]ms) with more internal foot rotation (F=14.60, p<0.001; MDgroup : 2.2[1.2] degrees, MDlimb : 4.2[1.3] degrees) compared to controls and their contralateral limb. There were no significant differences for cadence (F=2.43, p=0.13; MD: 4[3] steps/min), foot landing (X2 =1.28, p=0.53), or foot strike (X2 =1.24, p=0.54).
Conclusions:
Spatiotemporal and kinematic running adaptations may predispose young runners with initial LAS to secondary soft tissue dysfunction due to loss of stability from ligamentous structures and an overreliance on myotendinous control. Clinicians may consider targeting these maladaptations during gait-training interventions. This article is protected by copyright. All rights reserved.
To date, several biomechanical approaches have been used to assess knee kinematics and kinetics of kinematically aligned (KA) total knee arthroplasty (TKA) knees. Most of these assessments favor KA TKA over mechanically aligned TKA, supporting promising medium-term clinical results for calipered KA TKA. Although realistic boundary conditions for varus inclination of tibial joint line and varus limb alignment remain to be clarified, varus joint line inclination (medial proximal tibial angle <87 degrees) alone does not seem to increase knee adduction moment (KAM) and subsequent medial contact stress, while varus limb alignment carries a risk of increasing KAM. Preserving the original joint line and native ligament balance using calliper control of the bony resection undoubtedly gives the benefit of a natural feeling to the knee; however, further clinical studies are warranted to assess the long-term impact of KA TKA.
To date, applications of Systems Thinking (ST) in sport sciences are lacking with little existing practical work that adopted the approach. The aim of the article is to present an instantiation of ST in running towards demonstrating its utility. Two qualitative, principle tools in ST is demonstrated for a systemic problem in sport, namely recurring overuse injuries related to running. First, the growth-and-underinvestment system archetype is illustrated as a mechanism to differentiate short and long term solutions, incorporating the recent Nike Vaporfly running shoes and gait retraining. Secondly, a populated ice-berg model is provided of the runner and their environment: the runner-environment system is broken down into constituent units and then synthesised as the synergy between units; specifically considering the runner’s biomechanical properties, wearables and social media platforms. This article forms part of a more extensive project to contribute to a practical departure for ST in sport science; future work includes the quantified dynamic model of injury development from emergent interactions.
Background:
Indications for kinematically aligned total knee arthroplasty (KA-TKA) have remained contentious. This study aimed at exploring preoperative characteristics of patients who were suitable for and benefited from KA-TKA, based on the assessment of patient-reported outcome measures (PROMs).
Methods:
Subjects comprised 100 patients undergoing KA-TKA and 100 patients undergoing mechanically aligned (MA)-TKA due to end-stage osteoarthritis. Bone cuts were performed using portable navigation systems according to 3D planning data from computed tomography. At 2 years postoperatively, all 200 patients were assessed for PROMs, including Knee Society Score 2011, pain catastrophizing scale, and pain DETECT score. Multiple regression analysis was performed with activity subscore set as a dependent variable. Principal component analysis was used to evaluate patient satisfaction and function components transformed from the 3 PROMs and to compare these components between KA-TKA and MA-TKA.
Results:
Male gender or use of KA technique positively affected advanced activity score, whereas age, body mass index, preoperative pain DETECT score, and preoperative femorotibial angle showed negative effects. In principal component analysis, 38 KA-TKA patients achieved a higher function score, with satisfaction scores comparable to those from MA-TKA. These 38 patients were characterized by a higher percentage of males, younger age, and higher preoperative total activity score.
Conclusion:
From the perspective of PROMs, KA-TKA should be favored over MA-TKA for young active males, because these patient groups achieved higher functional activity when undergoing KA-TKA.
Purpose:
Medial tibial stress syndrome (MTSS) is one of the most common overuse injuries sustained by runners. Despite the prevalence of this injury, risk factors for developing MTSS remain unclear. The purpose of this study was to prospectively evaluate differences in passive range of motion, muscle strength, plantar pressure distributions, and running kinematics between runners who developed MTSS and those who did not.
Methods:
24 NCAA Division 1 cross country runners participated in this study. Participants underwent a clinical exam documenting passive range of motion and muscle strength at the hips and ankles. Plantar pressure analysis was used to quantify mediolateral pressure balances while walking and 3D motion capture was used to quantify running kinematics. Participants were followed for a two year period during which time any runners who developed MTSS were identified by the team's certified athletic trainer.
Results:
Runners who developed MTSS demonstrated tighter iliotibial bands (p=.046, ES=1.07), weaker hip abductors (p=.008, ES=1.51), more pressure under the medial aspect of their foot at initial foot contact(p=.001, ES=1.97), foot flat(p<.001, ES=3.25), and heel off (p=.034, ES=1.30), greater contralateral pelvic drop (p=0.021, ES=1.06), and greater peak amounts (p=0.017, ES=1.42) and durations (p<.001, ES=2.52) of rearfoot eversion during stance phase. A logistic regression (χ=21.31, p<.001) indicated that every 1% increase in eversion duration increased odds of developing MTSS by 1.38 (p=0.015).
Conclusions:
These findings demonstrate that the development of MTSS is multifactorial, with passive range of motion, muscle strength, plantar pressure distributions, and both proximal and distal kinematics all playing a role. We suggest that coaches or sports medicine professionals screening runners for injury risk consider adopting a comprehensive evaluation which includes all these areas.
Human walking can be viewed essentially as a continuum of anterior balance loss followed by a step that re-stabilizes balance. To secure balance an extended base of support can be assistive but healthy young adults tend to walk with relatively narrower steps compared to vulnerable populations (e.g. older adults and patients). It was, therefore, hypothesized that wide step walking may enhance dynamic balance at the cost of disturbed optimum coupling of muscle functions, leading to additional muscle work and associated reduction of gait economy. Young healthy adults may select relatively narrow steps for a more efficient gait. The current study focused on the effects of wide step walking on hip abductor and adductor muscles and spatio-temporal gait parameters. To this end, lower body kinematic data and ground reaction forces were obtained using an Optotrak motion capture system and AMTI force plates, respectively, while AnyBody software was employed for muscle force simulation. A single step of four healthy young male adults was captured during preferred walking and wide step walking. Based on preferred walking data, two parallel lines were drawn on the walkway to indicate 50% larger step width and participants targeted the lines with their heels as they walked. In addition to step width that defined walking conditions, other spatio-temporal gait parameters including step length, double support time and single support time were obtained. Average hip muscle forces during swing were modeled. Results showed that in wide step walking step length increased, Gluteus Minimus muscles were more active while Gracilis and Adductor Longus revealed considerably reduced forces. In conclusion, greater use of abductors and loss of adductor forces were found in wide step walking. Further validation is needed in future studies involving older adults and other pathological populations.
Of all the detrimental effects of spinal cord injury (SCI), one of the most devastating is the disruption of the ability to perform functional movement. Very little is known on the recovery of hindlimb joint kinematics after clinically-relevant contusive thoracic lesion in experimental animal models. A new functional assessment instrument, the dynamic feet distance (DFD) was used to describe the distance between the two feet throughout the gait cycle in normal and affected rodents. The purpose of this investigation was the evaluation and characterization of the DFD during treadmill locomotion in normal and T9 contusion injured rats, using three-dimensional (3D) instrumented gait analysis. Despite that normal and injured rats showed a similar pattern in the fifth metatarsal head joints distance excursion, we found a significantly wider distance between the feet during the entire gait cycle following spinal injury. This is the first study to quantify the distance between the two feet, throughout the gait cycle, and the biomechanical adjustments made between limbs in laboratory rodents after nervous system injury.
Study Design
Systematic literature review.
Objectives
This review sought to determine the efficacy of real-time visual and/or auditory feedback for modifying kinematics and kinetics during running gait.
Background
Real-time visual and auditory feedback has gained popularity in the clinical and research settings. Rehabilitation time and injury prevention may be improved when clinicians are able to modify running mechanics in a patient population.
Methods
A thorough search of PubMed, CINAHL, and Web of Science from 1989 to January 2015 was performed. The search sought articles that examined real-time visual or auditory feedback for the purposes of modifying kinematics or kinetics in injured or healthy runners. Study design and methodological quality were rated using a 20-point scale.
Results
Ten studies were identified for inclusion in the review, 2 of high and 8 of moderate methodological quality. There was a consensus in the literature that the use of real-time feedback is effective in reducing variables related to ground reaction forces, as well as in positively modifying previously identified risky lower extremity kinematic movement patterns in healthy runners and those with patellofemoral pain and chronic exertional compartment syndrome. No one method of feedback was identified as being superior. Mirror and 2-dimensional video feedback were identified as potential methods for running-gait modification in a clinical setting.
Conclusion
In conjunction with traditional therapeutic interventions, real-time auditory and visual feedback should be considered for treating injured runners or addressing potentially injurious running mechanics in a healthy population. J Orthop Sports Phys Ther 2015;45(8):576–584. doi:10.2519/jospt.2015.5823
Female runners have a high incidence of developing patellofemoral pain. Abnormal mechanics are thought to be an important contributing factor to patellofemoral pain. However, the contribution of abnormal trunk, hip, and foot mechanics to the development of patellofemoral pain within this cohort remains elusive. Therefore the aim of this study was to determine if significant differences during running exist in hip, trunk and foot kinematics between females with and without patellofemoral pain.
32 female runners (16 patellofemoral pain, 16 healthy control) participated in this study. All individuals underwent an instrumented gait analysis. Between-group comparisons were made for hip adduction, hip internal rotation, contra-lateral pelvic drop, contra-lateral trunk lean, rearfoot eversion, tibial internal rotation, as well as forefoot dorsiflexion and abduction
The patellofemoral pain group had significantly greater peak hip adduction and hip internal rotation. No differences in contra-lateral pelvic drop were found. A trend towards reduced contra-lateral trunk lean was found in the patellofemoral pain group. No significant differences were found in any of the rearfoot or forefoot variables but significantly greater shank internal rotation was found in the patellofemoral pain group.
We found greater hip adduction, hip internal rotation and shank internal rotation in female runners with patellofemoral pain. We also found less contra-lateral trunk lean in the patellofemoral pain group. This may be a potential compensatory mechanism for the poor hip control seen. Rehabilitation programs that correct abnormal hip and shank kinematics are warranted in this population.
Cross-sectional experimental laboratory study.
To examine differences in running mechanics between runners who had previously sustained iliotibial band syndrome (ITBS) and runners with no knee-related running injuries.
ITBS is the second leading cause of knee pain in runners and the most common cause of lateral knee pain. Despite its prevalence, few biomechanical studies have been conducted to better understand its aetiology. Because the iliotibial band has both femoral and tibial attachments, it is possible that atypical hip and foot mechanics could result in the development of ITBS.
The running mechanics of 35 females who had previously sustained ITBS were compared to 35 healthy age-matched and running distance-matched healthy females. Comparisons of hip, knee, and ankle 3-dimensional kinematics and internal moments during the stance phase of running gait were measured.
The ITBS group exhibited significantly greater peak rearfoot invertor moment, peak knee internal rotation angle, and peak hip adduction angle compared to controls. No significant differences in peak rearfoot eversion angle, peak knee flexion angle, peak knee external rotator moment, or peak hip abductor moments were observed between groups.
Females with a previous history of ITBS demonstrate a kinematic profile that is suggestive of increased stress on the iliotibial band. These results were generally similar to those reported for a prospective study conducted within the same laboratory environment.
Gender differences in kinematics during running have been speculated to be a contributing factor to the lower extremity injury rate disparity between men and women. Specifically, increased non-sagittal motion of the pelvis and hip has been implicated; however it is not known if this difference exists under a variety of locomotion conditions. The purpose of this study was to characterize gender differences in gait kinematics and muscle activities as a function of speed and surface incline and to determine if lower extremity anthropometrics contribute to these differences.
Whole body kinematics of 34 healthy volunteers were recorded along with electromyography of muscles on the right lower limb while each subject walked at 1.2, 1.5, and 1.8m/s and ran at 1.8, 2.7, and 3.6m/s with surface inclinations of 0%, 10%, and 15% grade. Joint angles and muscle activities were compared between genders across each speed-incline condition. Pelvis and lower extremity segment lengths were also measured and compared.
Females displayed greater peak hip internal rotation and adduction, as well as gluteus maximus activity for all conditions. Significant interactions (speed-gender, incline-gender) were present for the gluteus medius and vastus lateralis. Hip adduction during walking was moderately correlated to the ratio of bi-trochanteric width to leg length.
Our findings indicate females display greater non-sagittal motion. Future studies are needed to better define the relationship of these differences to injury risk.
The experimental study of joint kinematics in three dimensions requires the description and measurement of six motion components. An important aspect of any method of description is the ease with which it is communicated to those who use the data. This paper presents a joint coordinate system that provides a simple geometric description of the three-dimensional rotational and translational motion between two rigid bodies. The coordinate system is applied to the knee and related to the commonly used clinical terms for knee joint motion. A convenient characteristic of the coordinate system shared by spatial linkages is that large joint displacements are independent of the order in which the component translations and rotations occur.
When three-dimensional (3-D) human or animal movement is recorded using a photogrammetric system, bone-embedded frame positions and orientations are estimated from reconstructed surface marker trajectories using either nonoptimal or optimal algorithms. The effectiveness of these mathematical procedures in accommodating for both photogrammetric errors and skin movement artifacts depends on the number of markers associated with a given bone as well as on the size and shape characteristics of the relevant cluster. One objective of this paper deals with the identification of marker-cluster design criteria aimed at the minimization of error propagation from marker coordinates to bone-embedded frame position and orientation. Findings allow for the quantitative estimation of these errors for any given cluster configuration and suggest the following main design criteria. A cluster made up of four markers represents a good practical compromise. Planar clusters are acceptable, provided in quasi-isotropic distribution. The root mean square distance of the markers from their centroid should be greater than ten times the standard deviation of the marker position error. The second objective of this paper deals with the identification of the optimal cluster position and orientation on the limb aimed at the minimization of error propagation to anatomical landmark laboratory coordinates. Cluster position should be selected to minimize skin movement artifacts. The longest principal axis of the marker distribution should be oriented toward the relevant anatomical landmark position.
There is little information on how a change in one feature of an individual’s running mechanics affects other aspects of running style. This study manipulated experimental conditions such that eight subjects ran with three different step lengths, three step widths, and three varying degrees of shoulder rotation. The effect of these changes on rearfoot pronation measures, step length, and step width were examined. Results showed that varying step length over a range of 18 cm and shoulder rotation over a range of 17° caused no significant differences in maximal pronation angle, total amount of pronation, or maximal pronation velocity. Varying step width from landing approximately 5 cm lateral to the midline to crossing over a midline by 2 cm increased the maximum pronation from 12.2 to 18.3°, the amount of pronation from 14.1 to 21.1°, and maximal pronation velocity from. 329°/s to 535°/s. It is suggested that runners with problems due to excessive pronation might try changing step width. Changes in step width and shoulder rotation had no significant effect on step length, and alterations to shoulder rotation did not affect step length or step width significantly. These results suggest that a runner attempts to maintain some aspects of running mechanics despite major alterations to other elements of running style.
The determination of statistical power for a repeated measures experimental study is a necessary, but difficult and seldom done, calculation. The purpose of this study was to provide practical methods for the a priori determination of power for the repeated measures (RM) analysis of variance (ANOVA). Stepwise regression analysis procedures were used to derive 10 power approximation equations for the main and interaction effects of the 1-way RM, 2-way mixed and 2-way RM ANOVA designs. The theoretically correct power values were calculated using the program DATASIM (Bradley, 1988) for various levels of effect size, number of levels of each factor, sample size, and mean correlations among RM factor levels. Potvin and Schutz's (in press) equations for estimating the error variance were utilized for computing power for the 2-way RM ANOVA. The derived equations showed a high level of precision in approximating power (R2 = .97 to .99, SEE = .0 12 to .035) with 9 to 16 predictor variables for the 1-way RM and the 2-way mixed designs. For the 2-way RM design, however, the levels of precision were relatively low for the main effect (R2 = .66 and .81 for α levels .01 and .05, respectively), and the residuals of the regression equation for the interaction effect showed a nonlinear relation with the criterion variable. Recommendations are given for the practical usage of the derived equations, and examples for calculating power for each design are provided.
Background:
Women have higher non-contact anterior cruciate ligament injury rate than men do in sport activities. Non-contact anterior cruciate ligament injuries frequently occur in sports requiring cutting tasks. Alternated motor control strategies have identified as a potential risk factor for the non-contact anterior cruciate ligament injuries. The purpose of this study was to compare the patterns of knee kinematics and electromyographic activities in running, side-cutting, and cross-cutting between men and women recreational athletes.
Methods:
Three-dimensional kinematic data of the knee and electromyographic data of selected muscles across the knee joint were collected for 11 men and 9 women recreational athletes in running, side-cutting, and cross-cutting. Regression analyses with dummy variables for comparison of knee motion patterns between men and women.
Results:
Women tend to have less knee flexion angles, more knee valgus angles, greater quadriceps activation, and lower hamstring activation in comparison to men during the stance phase of each of the three athletic tasks. Literatures suggest these alternated knee motion patterns of women tend to increase the load on the anterior cruciate ligament.
Conclusion:
Women on average may have certain motor control strategies that may alter their knee motion patterns. Women's altered knee motion patterns may tend to increase the load on the anterior cruciate ligament in the selected athletic tasks, which may contribute to the increased anterior cruciate ligament injury rate among women.
Relevance:
Non-contact anterior cruciate ligament injuries frequently occur in sports. Altered motor control strategies and lower extremity motion patterns are likely to play an important role in non-contact anterior cruciate ligament injuries. Non-contact anterior cruciate ligament injuries may be prevented by correcting altered motor control strategies and associated lower extremity motion patterns through certain training programs.
In walking, humans prefer a moderate step width that minimizes energetic cost and vary step width from step-to-step to maintain lateral balance. Arm swing also reduces energetic cost and improves lateral balance. In running, humans prefer a narrow step width that may present a challenge for maintaining lateral balance. However, arm swing in running may improve lateral balance and help reduce energetic cost. To understand the roles of step width and arm swing, we hypothesized that net metabolic power would be greater at step widths greater or less than preferred and when running without arm swing. We further hypothesized that step width variability (indicator of lateral balance) would be greater at step widths greater or less than preferred and when running without arm swing. Ten subjects ran (3m/s) at four target step widths (0%, 15%, 20%, and 25% leg length (LL)) with arm swing, at their preferred step width with arm swing, and at their preferred step width without arm swing. We measured metabolic power, step width, and step width variability. When subjects ran at target step widths less (0% LL) or greater (15%, 20%, and 25% LL) than preferred, both net metabolic power demand (by 3%, 9%, 12%, and 15%) and step width variability (by 7%, 33%, 46%, and 69%) increased. When running without arm swing, both net metabolic power demand (by 8%) and step width variability (by 9%) increased compared to running with arm swing. It appears that humans prefer to run with a narrow step width and swing their arms so as to minimize energetic cost and improve lateral balance.
Investigate lower extremity kinematics in runners with patellofemoral pain (PFP) syndrome during a prolonged run.
For this study, 20 runners with PFP and 20 uninjured controls performed a prolonged run on a treadmill at a self-selected pace. The run ended based on HR, perceived exertion, or level of knee pain. Kinematic data were analyzed at the beginning and at the end of the run.
The PFP group demonstrated less peak knee flexion, peak hip adduction, eversion excursion, peak knee flexion velocity, peak hip adduction velocity, and peak hip internal rotation velocity compared with controls. A significant main effect for time indicated that increases in most kinematic variables occurred at the end of the run. Interestingly, five runners with PFP displayed atypical motions of knee valgus and eight displayed hip abduction during the first half of stance.
The PFP group as a whole displayed less overall motion compared with controls. This may be indicative of a strategy aimed at limiting lower extremity movement to reduce pain. However, increases in joint motion occurred at the end of the run where pain levels were greatest. Three distinct PFP subgroups were noted, and each demonstrated unique kinematic mechanisms that may be associated with PFP. In the knee valgus subgroup, increased knee valgus and decreased peak motions were noted in other joints. In the hip abduction subgroup, less knee flexion and motion overall was noted. In the subgroup that displayed typical first half patterns (knee and hip adduction), increased hip internal rotation and decreased knee internal rotation were observed. These results suggest that several different kinematic mechanisms related to PFP may exist.
Recent studies have suggested that excessive hip internal rotation during dynamic tasks may be associated with patellofemoral pain. Although diminished hip-muscle strength and altered femoral morphologic characteristics have been implicated in abnormal hip rotation in persons with patellofemoral pain, no study has confirmed this hypothesis.
Women with patellofemoral pain would demonstrate increased average hip internal rotation, decreased hip-muscle performance, and abnormal femoral shape compared with controls. Furthermore, measures of hip strength and femoral shape are predictive of average hip internal rotation during running.
Cross-sectional study; Level of evidence, 3.
Nineteen women with patellofemoral pain and 19 pain-free controls participated. Lower extremity kinematics during running, hip-muscle performance, and femoral morphologic characteristics on magnetic resonance imaging were quantified. Independent t tests were used to assess group differences. Stepwise linear regression was used to determine whether measures of strength and/or structure were predictive of average hip internal rotation during running.
Participants with patellofemoral pain demonstrated significantly greater average hip internal rotation (8.2 degrees +/- 6.6 degrees vs 0.3 degrees +/- 3.6 degrees ; P < .001), reduced hip-muscle strength in 8 of 10 hip strength measurements, and greater femoral inclination (132.8 degrees +/- 5.2 degrees vs 128.4 degrees +/- 5.0 degrees ; P = .011) compared with controls. Stepwise regression revealed that isotonic hip extension endurance was the only predictor of average hip internal rotation (r = -.451; P = .004).
Abnormal hip kinematics in women with patellofemoral pain appears to be the result of diminished hip-muscle performance as opposed to altered femoral structure. The results suggest that assessment of hip-muscle performance should be considered in the evaluation and treatment of patellofemoral joint dysfunction.
The original Physical Activity Readiness Questionnaire (PAR-Q) offers a safe preliminary screening of candidates for exercise testing and prescription, but it screens out what seems an excessive proportion of apparently healthy older adults. To reduce unnecessary exclusions, an expert committee established by Fitness Canada has now revised the questionnaire wording. The present study compares responses to the original and the revised PAR-Q questionnaire in 399 men and women attending 40 accredited fitness testing centres across Canada. The number of subjects screened out by the revised test decreased significantly (p < .05), from 68 to 48 of the 399 subjects. The change reflects in part the inclusion of individuals who had made an erroneous positive response to the original question regarding high blood pressure. There is no simple gold standard to provide an objective evaluation of the sensitivity and specificity of either questionnaire format, but the revised wording has apparently had the intended effect of reducing positive responses, particularly to the question regarding an elevation of blood pressure.
Zatsiorsky et al. (in Contemporary Problems in Biomechanics, pp. 272-291, CRC Press, Massachusetts, 1990a) obtained, by means of a gamma-ray scanning technique, the relative body segment masses, center of mass (CM) positions, and radii of gyration for samples of college-aged Caucasian males and females. Although these data are the only available and comprehensive set of inertial parameters regarding young adult Caucasians, they have been rarely utilized for biomechanical analyses of subjects belonging to the same or a similar population. The main reason is probably that Zatsiorsky et al. used bony landmarks as reference points for locating segment CMs and defining segment lengths. Some of these landmarks were markedly distant from the joint centers currently used by most researchers as reference points. The purpose of this study was to adjust the mean relative CM positions and radii of gyration reported by Zatsiorsky et al., in order to reference them to the joint centers or other commonly used landmarks, rather than the original landmarks. The adjustments were based on a number of carefully selected sources of anthropometric data.
The overall goal of this work was to determine an optimal surface-tracking marker set for tracking motion of the tibia during natural cadence walking. Eleven different marker sets were evaluated. The marker sets differed in the location they were attached to the shank, the method used to attach the marker sets to the segment and the physical characteristics of the marker sets. Angular position during stance for each marker set was expressed relative to the orientation of the tibia as measured using bone anchored markers. A marker set consisting of four markers attached to a rigid shell positioned over the distal lateral shank and attached to the leg using an underwrap attachment yielded the best estimate of tibial rotation. Rotational deviations of+/-2 degrees about the medio-lateral and antero-posterior axes, and+/-4 degrees about the longitudinal axis did occur even when using the optimal set of markers.
It is important to understand the day‐to‐day variability that is attributed to repositioning of markers especially when assessing a treatment effect or response over time. While previous studies have reported reliability of waveform patterns, none have assessed the repeatability of discrete points such as peak angles, velocities and angular excursions which are often used when making statistical and clinical comparisons. The purpose of this study was to compare the within‐ and between‐day variability of discrete kinematic, kinetic, and ground reaction force (GRF) data collected during running. Comparisons for 20 recreational runners were evaluated for within‐ and between‐day reliability of discrete 3D kinematic, kinetic, and GRF variables. The results indicated that within‐day comparisons were more reliable than between‐day. Joint angular velocity and angular excursion values were more reliable between‐days as compared to absolute peak angle measures and may be more useful in interpreting changes in treatment over time. Between‐day kinematic and kinetic sagittal plane values were more reliable than secondary plane values. Reliability of GRF data was greater than kinematic and kinetic data for between‐day comparisons.
© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
To compare differences in hip and knee kinematics and kinetics in male and female recreational runners.
Gait analysis of 20 men and 20 women recreational runners.
Female runners are reported to be more likely to sustain certain lower extremity injuries compared to their male counterparts. This has been attributed, in part, to differences in their structure and it has been postulated that these structural differences may lead to differences in running mechanics. It was hypothesized that females would exhibit greater peak hip adduction, hip internal rotation, knee abduction and decreased knee internal rotation compared to their male counterparts. It was also hypothesized that females would exhibit greater hip and knee negative work in the frontal and transverse planes compared to males.
Comparisons of hip and knee three-dimentional joint angles and negative work during the stance phase of running gait were made between genders.
Female recreational runners demonstrated a significantly greater peak hip adduction, hip internal rotation and knee abduction angle compared to men. Female recreational runners also demonstrated significantly greater hip frontal and transverse plane negative work compared to male recreational runners.
Female recreational runners exhibit significantly different lower extremity mechanics in the frontal and transverse planes at the hip and knee during running compared to male recreational runners.
Understanding the differences in running mechanics between male and female runners may lend insight into the etiology of different injury patterns seen between genders. In addition, these results suggest that care should be taken to account for gender when studying groups of male and female recreational runners.
Motion at the midfoot joints can contribute significantly to overall foot motion during gait. However, there is little information regarding the kinematic coupling relationship at the midfoot. The purpose of the present study was to determine whether the coupling relationship at the midfoot and subtalar joints was affected when step width was manipulated during running.
Twelve subjects ran over-ground at self-selected speeds using three different step widths (normal, wide, cross-over). Coupling at the midfoot (forefoot relative to rearfoot) and subtalar (rearfoot relative to shank) joints was assessed using cross-correlation techniques.
Rearfoot kinematics were significantly different from normal running in cross-over running (P<0.05) but not in wide running. However, coupling between rearfoot eversion/inversion and shank rotation was consistently high (r>0.917), regardless of step width. This was also the case for coupling between rearfoot frontal plane motion and forefoot sagittal plane (r<-0.852) and forefoot transverse plane (r>0.946) motion. There was little evidence of coupling between rearfoot frontal plane motion and forefoot frontal plane motion in any of the conditions.
Forefoot frontal plane motion appeared to have little effect on rearfoot frontal plane motion and thus, had no effect on motion at the subtalar joint. The strong coupling of forefoot sagittal and transverse plane motions with rearfoot frontal plane motion suggests that forefoot motion exerts an important influence on subtalar joint kinematics.
Identification of mechanical factors associated with patellofemoral pain, the most prevalent running injury, is necessary to help in injury prevention, but unfortunately they remain elusive.
Runners who develop patellofemoral pain have increased knee joint angular impulse in the frontal plane.
Case control study; Level of evidence, 3.
A retrospective study compared knee abduction impulses of 20 patellofemoral pain patients with those of 20 asymptomatic patients. A second prospective study quantified knee angular impulses during the stance phase of running of 80 runners at the beginning of the summer running season. Epidemiologic data were then collected, recording the type and severity of injury of these runners during a 6-month running period.
The patellofemoral pain patients in the retrospective study had significantly higher (P = .026) knee abduction impulses (17.0 +/- 8.5 Nms) than did the asymptomatic patients (12.5 +/- 5.5 Nms). Six patients developed patellofemoral pain during the prospective study. The prospective data showed that patients who developed patellofemoral pain had significantly higher (P = .042) knee abduction impulses (9.2 +/- 3.7 Nms) than did matched patients who remained uninjured (4.7 +/- 3.5 Nms).
The data indicate that increased knee abduction impulses should be deemed risk factors that play a role in the development of patellofemoral pain in runners.
Footwear and running style can influence knee angular impulse, and the appropriate manipulation of these variables may play a preventive role for patients who are predisposed to patellofemoral pain.
Iliotibial band syndrome is the leading cause of lateral knee pain in runners. Despite its high prevalence, little is known about the biomechanics that lead to this syndrome. The purpose of this study was to prospectively compare lower extremity kinematics and kinetics between a group of female runners who develop iliotibial band syndrome compared to healthy controls. It was hypothesized that runners who develop iliotibial band syndrome will exhibit greater peak hip adduction, knee internal rotation, rearfoot eversion and no difference in knee flexion at heel strike. Additionally, the iliotibial band syndrome group were expected to have greater hip abduction, knee external rotation, and rearfoot inversion moments.
A group of healthy female recreational runners underwent an instrumented gait analysis and were then followed for two years. Eighteen runners developed iliotibial band syndrome. Their initial running mechanics were compared to a group of age and mileage matched controls with no history of knee or hip pain. Comparisons of peak hip, knee, rearfoot angles and moments were made during the stance phase of running. Variables of interest were averaged over the five running trials, and then averaged across groups.
The iliotibial band syndrome group exhibited significantly greater hip adduction and knee internal rotation. However, rearfoot eversion and knee flexion were similar between groups. There were no differences in moments between groups.
The development of iliotibial band syndrome appears to be related to increased peak hip adduction and knee internal rotation. These combined motions may increase iliotibial band strain causing it to compress against the lateral femoral condyle. These data suggest that treatment interventions should focus on controlling these secondary plane movements through strengthening, stretching and neuromuscular re-education.
Patellofemoral pain is commonly associated with lower extremity joint rotations that decrease retropatellar contact area and subsequently increase retropatellar stress during weightbearing activities. People with patellofemoral pain are thought to be capable of avoiding such harmful mechanics during activities with low external demands. However, this may not be possible during more demanding activities. The purpose of this study was to analyze lower extremity mechanics in females with and without patellofemoral pain during three different activities. Specifically, we sought to determine if differences between groups increase with increasingly demanding activities.
20 females with patellofemoral pain and 20 healthy female controls performed single leg squats, running, and repetitive single leg jumps as their three-dimensional lower extremity mechanics were recorded. Transverse and frontal plane hip and knee kinematics were compared between groups for all activities.
Differences in the variables of interest between groups did not generally depend on the nature of the activity. The patellofemoral pain group performed all three activities with 4.3 degrees greater knee external rotation (P=0.06), 3.5 degrees greater hip adduction (P=0.012), and 3.9 degrees decreased hip internal rotation with respect to the control group (P=0.01).
These results suggest that females with patellofemoral pain do not employ different mechanics as demand of the activity increases. Rather, females with patellofemoral pain seem to demonstrate similar abnormal lower extremity mechanics across a variety of activities.
Orthopedic physical assessment. Philadelphia: W.B. Saunders Company
- Dj Magee
Magee DJ. Orthopedic physical assessment. Philadelphia: W.B. Saunders Company ; 1997.