Lower-limb joint work and power are modulated during load carriage based on load configuration and walking speed

Effects of a passive upper-body exoskeleton on whole-body kinematics, leg muscle activity, and discomfort during a carrying task

OBJECTIVE

To compare whole-body kinematics, leg muscle activity, and discomfort while performing a 10-min carrying task with and without a passive upper-body exoskeleton (CarrySuitⓇ), for both males and females.

BACKGROUND

Diverse commercial passive exoskeletons have appeared on the market claiming to assist lifting or carrying task. However, evidence of their impact on kinematics, muscle activity, and discomfort while performing these tasks are necessary to determine their benefits and/or limitations.

METHOD

Sixteen females and fourteen males carried a 15kg load with and without a passive exoskeleton during 10-min over a round trip route, in two non-consecutive days. Whole-body kinematics and leg muscle activity were evaluated for each condition. In addition, leg discomfort ratings were quantified before and immediately after the task.

RESULTS

The gastrocnemius and vastus lateralis muscle activity remained constant over the task with the exoskeleton. Without the exoskeleton a small decrease of gastrocnemius median activation was observed regardless of sex, and a small increase in static vastus lateralis activation was observed only for females. Several differences in sagittal, frontal, and transverse movements' ranges of motion were found between conditions and over the task. With the exoskeleton, ROM in the sagittal plane increased over time for the right ankle and pelvis for both sexes, and knees for males only. Thorax ROMs in the three planes were higher for females only when using the exoskeleton. Leg discomfort was lower with the exoskeleton than without.

CONCLUSION

The results revealed a positive impact on range of motion, leg muscle activity, and discomfort of the tested exoskeleton.

Lower-Extremity Energetic Distribution During Rate-Controlled Ballet Jumps (Sautés) in Healthy Dancers

Dancers frequently perform jumps in the context of a prolonged, continuous dance piece. The purpose of this study is to explore the lower-extremity energetics in healthy dancers performing repetitive dance jumps (sautés) before and after typical dance-specific choreography. Lower-extremity kinetic data were collected from 14 healthy female dancers during a series of sautés performed before and after 3 minutes of dance. Percent contributions of the lower-extremity joints to the whole-limb mechanical energy expenditure during ground contact were calculated. The jumps performed at the beginning were compared with the jumps at the end of the dance choreography. Dancers maintained the jump rate and consistent whole-limb mechanical energy expenditure between the jump series. As expected, for both jump series, the sautés had greater relative energetic contribution from the ankle and knee as compared with lesser contribution from the hip and toe. However, we observed lesser contribution from the knee and greater contribution from the hip after a 3-minute dance. After performing typical dance choreography, the dancers demonstrated a distal to proximal redistribution of individual joints' contribution to whole-limb mechanical energy expenditure.

Biomechanical Analysis of Human Gait When Changing Velocity and Carried Loads: Simulation Study with OpenSim

Walking is one of the main activities of daily life and gait analysis can provide crucial data for the computation of biomechanics in many fields. In multiple applications, having reference data that include a variety of gait conditions could be useful for assessing walking performance. However, limited extensive reference data are available as many conditions cannot be easily tested experimentally. For this reason, a musculoskeletal model in OpenSim coupled with gait data (at seven different velocities) was used to simulate seven carried loads and all the combinations between the two parameters. The effects on lower limb biomechanics were measured with torque, power, and mechanical work. The results demonstrated that biomechanics was influenced by both speed and load. Our results expand the previous literature: in the majority of previous work, only a subset of the presented conditions was investigated. Moreover, our simulation approach provides comprehensive data that could be useful for applications in many areas, such as rehabilitation, orthopedics, medical care, and sports.

Concentric and eccentric hip musculotendon work depends on backpack loads and walking slopes

Hip muscle weakness is associated with low back and leg injuries. In addition, hiking with heavy loads is linked to high incidence of overuse injuries. Walking with heavy loads on slopes alters hip biomechanics compared to unloaded walking, but individual muscle mechanical work in these challenging conditions is unknown. Using movement simulations, we quantified hip muscle concentric and eccentric work during walking on 0° and ±10° slopes with, and without 40% bodyweight added loads, and with and without a hip belt. For gluteus maximus, psoas, iliacus, gluteus medius, and biceps femoris long head, both concentric and eccentric work were greatest during uphill walking. For rectus femoris and semimembranosus, concentric work was greatest during uphill and eccentric work was greatest during downhill walking. Loaded walking had greater concentric and eccentric work from rectus femoris, biceps femoris long head, and gluteus maximus. Psoas concentric work was greatest while carrying loads regardless of hip belt usage, but eccentric work was only greater than unloaded walking when using a hip belt. Loaded and uphill walking had high concentric work from gluteus maximus, and high eccentric work from gluteus medius and biceps femoris long head. Carrying heavy loads uphill may lead to excessive hip muscle fatigue and heightened injury risk. Effects of the greater eccentric work from hip flexors when wearing a hip belt on lumbar spine forces and pelvic stability should be investigated. Military and other occupational groups who carry heavy backpacks with hip belts should maintain eccentric strength of hip flexors and hamstrings.

Effects of Walking Speed and Added Mass on Hip Joint Quasi-Stiffness in Healthy Young and Middle-Aged Adults

Joint quasi-stiffness has been often used to inform exoskeleton design. Further understanding of hip quasi-stiffness is needed to design hip exoskeletons. Of interest are wearer responses to walking speed changes with added mass of the exoskeleton. This study analyzed hip quasi-stiffness at 3 walking speed levels and 9 added mass distributions among 13 young and 16 middle-aged adults during mid-stance hip extension and late-stance hip flexion. Compared to young adults, middle-aged adults maintained a higher quasi-stiffness with a smaller range. For a faster walking speed, both age groups increased extension and flexion quasi-stiffness. With mass evenly distributed on the pelvis and thighs or biased to the pelvis, both groups maintained or increased extension quasi-stiffness. With mass biased to the thighs, middle-aged adults maintained or decreased extension quasi-stiffness while young adults increased it. Young adults decreased flexion quasi-stiffness with added mass but not in any generalizable pattern with mass amounts or distributions. Conversely, middle-aged adults maintained or decreased flexion quasi-stiffness with even distribution on the pelvis and thighs or biased to the pelvis, while no change occurred if biased to the thighs. In conclusion, these results can guide the design of a hip exoskeleton's size and mass distribution according to the intended user's age.

Maintaining soldier musculoskeletal health using personalised digital humans, wearables and/or computer vision

OBJECTIVES

The physical demands of military service place soldiers at risk of musculoskeletal injuries and are major concerns for military capability. This paper outlines the development new training technologies to prevent and manage these injuries.

DESIGN

Narrative review.

METHODS

Technologies suitable for integration into next-generation training devices were examined. We considered the capability of technologies to target tissue level mechanics, provide appropriate real-time feedback, and their useability in-the-field.

RESULTS

Musculoskeletal tissues' health depends on their functional mechanical environment experienced in military activities, training and rehabilitation. These environments result from the interactions between tissue motion, loading, biology, and morphology. Maintaining health of and/or repairing joint tissues requires targeting the "ideal" in vivo tissue mechanics (i.e., loading and strain), which may be enabled by real-time biofeedback. Recent research has shown that these biofeedback technologies are possible by integrating a patient's personalised digital twin and wireless wearable devices. Personalised digital twins are personalised neuromusculoskeletal rigid body and finite element models that work in real-time by code optimisation and artificial intelligence. Model personalisation is crucial in obtaining physically and physiologically valid predictions.

CONCLUSIONS

Recent work has shown that laboratory-quality biomechanical measurements and modelling can be performed outside the laboratory with a small number of wearable sensors or computer vision methods. The next stage is to combine these technologies into well-designed easy to use products.

Effects of Occupational Load on the Acceleration, Change of Direction Speed, and Anaerobic Power of Police Officers

ABSTRACT

Kukić, F, Janković, R, Dawes, JJ, Orr, R, and Koropanovski, N. Effects of occupational load on the acceleration, change of direction speed, and anaerobic power of police officers. J Strength Cond Res XX(X): 000-000, 2022-Police officers engage in movements such as foot pursuits, sudden directional changes, or prolonged sprinting while wearing occupational loads (including body armor, baton, radio, handcuffs, and sidearm). This study investigated the effects of incrementally heavier loads carried by police students on their physical performance. Police students (n = 63; male n = 39 male and 24 female students) performed an acceleration over a 10-m distance (Acc10m), Illinois agility test (IAT), and 300-yard shuttle run test (ShR300y) without load, with a 5-kg load (handgun, spare empty magazine, baton, and handcuffs), and with a 10-kg load (loaded vest). The effects of different load conditions were investigated for both sexes using a repeated-measure analysis of variance and Cohen's effect size. Female students carried relatively heavier loads and were slower than male students in Acc10m, IAT, and ShR300y. Load significantly (p < 0.001) impaired the performance in Acc10m, IAT, and ShR300y in both sexes, but the effects were greater (p < 0.001) among female police students. A load as little as 5 kg was sufficient to reduce Acc10m, IAT, and ShR300y among police students. Increasing the load to 10 kg (i.e., wearing the body armor) did not significantly affect Acc10m and IAT among male students, but it did affect Acc10m and IAT among female students. Sprint endurance (i.e., ShR300y) was strongly affected by both loads regardless of sex. Strength and conditioning programs should focus on strength, power, and anaerobic endurance to improve performance while carrying occupational loads. Occasional training with loads similar to those at work may further ensure that officers are fit for purpose.

Biomechanical and physiological effects of female soldier load carriage: A scoping review

Loads carried by military populations can affect those of smaller stature, such as the average female, due to the higher percentage of body weight the loads represent. Despite this, most load carriage research is performed on males. Peer reviewed articles were collected from four databases to summarize available research on biomechanical and physiological effects of load carriage on females in the military. Extraction and thematic analysis were performed on 18 articles. 39% looked at biomechanical differences between loads in females, 61% looked at how the same load affected males and females, 44% looked at sex-by-load interaction effects, and 72% discussed impacts of load on females. The research revealed that military load carriage affects the biomechanics and physiology differently in females and to a greater extent than in males. Several gaps in available literature were found. Very few studies used military participants, military equipment, and/or employed occupationally relevant data collection methodologies.

Modulation of Achilles tendon force with load carriage and exosuit assistance

Exosuits have the potential to assist locomotion in both healthy and pathological populations, but the effect of exosuit assistance on the underlying muscle-tendon tissue loading is not yet understood. In this study, we used shear wave tensiometers to characterize the modulation of Achilles tendon force with load carriage and exosuit assistance at the ankle. When walking (1.25 m/s) unassisted on a treadmill with load carriage weights of 15 and 30% of body weight, peak Achilles tendon force increased by 11 and 23%, respectively. Ankle exosuit assistance significantly reduced peak Achilles tendon force relative to unassisted, although the magnitude of change was variable across participants. Peak Achilles tendon force was significantly correlated with peak ankle torque for unassisted walking across load carriage conditions. However, when ankle plantarflexor assistance was applied, the relationship between peak tendon force and peak biological ankle torque was no longer significant. An outdoor pilot study was conducted in which a wearable shear wave tensiometer was used to measure Achilles tendon wave speed and compare across an array of assistance loading profiles. Reductions in tendon loading varied depending on the profile, highlighting the importance of in vivo measurements of muscle and tendon forces when studying and optimizing exoskeletons and exosuits.

Dance-based exergaming on postural stability and kinematics in people with chronic stroke - A preliminary study

INTRODUCTION

The study evaluated the feasibility, and compliance of a dance-based exergaming (DBExG) on postural stability (PS) and lower extremity (LE) kinematics, along with post-intervention changes in gait function and falls self-efficacy in people with chronic stroke (PwCS).

METHODS

Fifteen PwCS underwent DBExG for six weeks using Kinect "Just Dance 3." Pre- to post- changes were recorded during DBExG assessment on a fast-paced song (130 bpm) using an 8-camera motion capture system to assess PS (center of mass [CoM] excursions [EXs] in the anterior-posterior [AP] and mediolateral [ML] directions) and LE kinematics (hip, knee, and ankle joint angle EXs). Gait function was also assessed with gait parameters, such as gait speed, cadence, and gait symmetry on an electronic walkway. Falls self-efficacy was recorded with Falls Efficacy Scale (FES).

RESULTS

The AP and ML CoM EXs and paretic joint angle EXs significantly increased pre- to post- DBExG assessment (p < .05). Gait parameters, and falls self-efficacy measures significantly changed pre- to post- DBExG (p < .05).

CONCLUSIONS

Results exhibited the feasibility of the proposed DBExG for positively impacting postural stability, and kinematics, along with increasing gait function and falls self-efficacy among PwCS.

The influence of step-down technique on lower extremity mechanics during curb descent

When stepping down from a curb, individuals typically make initial ground contact with either their rearfoot or forefoot. The purpose of this study was to compare vertical ground reaction forces, lower extremity mechanics, and intra-limb work distribution when individuals adopt a rearfoot technique vs. a forefoot technique, during simulated curb descent. Sixteen subjects stepped down from a platform with both a rearfoot and a forefoot technique. Vertical ground reaction forces and sagittal plane joint kinematics and kinetics were examined for the lead limb during the step-down task. Paired t-tests were used for comparison. Subjects demonstrated greater ankle joint power and negative work, and less hip joint power and negative work, with the forefoot technique vs. the rearfoot technique. Total lower extremity negative work was greater for the forefoot technique vs. the rearfoot technique. The percent contribution to the total negative work was greater for the ankle joint, and less for the hip and knee joints, with the forefoot technique vs. the rearfoot technique. The results of this study may provide insight into how curb descent technique can be modified to alter lower extremity loading.

The Added Value of Musculoskeletal Simulation for the Study of Physical Performance in Military Tasks

The performance of military tasks is often exacerbated by additional load carriage, leading to increased physical demand. Previous studies showed that load carriage may lead to increased risk of developing musculoskeletal injuries, a reduction in task speed and mobility, and overall performance degradation. However, these studies were limited to a non-ambulatory setting, and the underlying causes of performance degradation remain unclear. To obtain insights into the underlying mechanisms of reduced physical performance during load-carrying military activities, this study proposes a combination of IMUs and musculoskeletal modeling. Motion data of military subjects was captured using an Xsens suit during the performance of an agility run under three different load-carrying conditions (no load, 16 kg, and 31 kg). The physical performance of one subject was assessed by means of inertial motion-capture driven musculoskeletal analysis. Our results showed that increased load carriage led to an increase in metabolic power and energy, changes in muscle parameters, a significant increase in completion time and heart rate, and changes in kinematic parameters. Despite the exploratory nature of this study, the proposed approach seems promising to obtain insight into the underlying mechanisms that result in performance degradation during load-carrying military activities.

Military load carriage effects on the gait of military personnel: A systematic review

Carrying heavy loads results in biomechanical changes to gait and to an increased risk of injury in soldiers. The aim of this review is to examine the effects of military specific load carriage on the gait of soldiers. The Web of Science, PubMed and CINAHL databases were searched, a total of 1239 records were screened and 20 papers were included in the review. Participant, load and task characteristics and a summary of key findings were extracted. Due to heterogeneity in the reviewed studies, analysis was restricted to qualitative synthesis. There were limited effects on spatio-temporal variables but consistently reported increased trunk, hip and knee flexion and increased hip and knee extension moments. Muscle activation of lower limb and trunk muscles were also increased with loads. However, there were some conflicting findings for most parameters reviewed and apart from spatio-temporal parameters the findings of this review were in line with previous reviews of combined military and civilian populations.

Lower Limb Biomechanical Responses During a Standardized Load Carriage Task are Sex Specific

INTRODUCTION

The purpose of this study was to investigate sex-specific lower limb biomechanical adaptations during a standardized load carriage task in response to a targeted physical training program.

MATERIALS AND METHODS

Twenty-five healthy civilians (males [n = 13] and females [n = 12]) completed a load carriage task (5 km at 5.5 km·h-1, wearing a 23 kg vest) before and after a 10-week lower-body-focused training program. Kinematics and ground reaction force data were collected during the task and were used to estimate lower limb joint kinematics and kinetics (i.e., moments and powers). Direct statistical comparisons were not conducted due to different data collection protocols between sexes. A two-way repeated measures ANOVA tested for significant interactions between, and main effects of training and distance marched for male and female data, respectively.

RESULTS

Primary kinematic and kinetic changes were observed at the knee and ankle joints for males and at the hip and knee joints for females. Knee joint moments increased for both sexes over the 5 km distance marched (P > .05), with males demonstrating significant reductions in peak knee joint extension after training. Hip adduction, internal rotation, and knee internal rotation angles significantly increased after the 5 km load carriage task for females but not males.

CONCLUSION

Differences in adaptive gait strategies between sexes indicate that physical training needs to be tailored to sex-specific requirements to meet standardized load carriage task demands. The findings highlighted previously unfound sex-specific responses that could inform military training and facilitate the integration of female soldiers into physically demanding military roles.

Repeated sprints alter mechanical work done by hip and knee, but not ankle, sagittal moments

OBJECTIVES

To quantify the changes in work done by lower limb joint moments during maximal speed running following a sports-specific repeated running protocol.

DESIGN

Observational with repeated-measures.

METHODS

Recreational athletes (n = 18 (9 females), aged = 26.2 ± 6.2 years) performed 12 maximal 30-m sprints on a non-motorised treadmill. Three-dimensional kinematics and ground reaction forces were subsequently recorded during a 10-m maximal overground sprint before and immediately after the repeated running protocol, from which we calculated work done by sagittal plane hip, knee, and ankle moments. Relative work (J/kg) was reported as a percentage of positive and negative work done by the sum of joint moments.

RESULTS

Following the repeated running protocol, maximal sprint speed decreased by 19% and was accompanied by reductions in total positive (-1.47 J/kg) and negative (-0.92 J/kg) work, in addition to work done by hip (-0.43 to -0.82 J/kg) and knee (-0.28 J/kg) moments during swing. Compared to before the repeated running protocol, less relative work was done by hip (-9%) and knee (-3%) extension moments during swing. Reductions in work done by hip and knee joint moments during swing were significantly correlated with reductions in maximum running speed (r = 0.61-0.89, p < 0.05).

CONCLUSIONS

A sports-specific repeated running protocol resulted in reductions in mechanical work done by sagittal plane hip and knee joint moments during maximal overground sprinting. Interventions focused on maintaining positive work done by the hip flexors/extensors and negative work done by knee flexors/extensors during the swing phase of running may help prevent reductions in speed following repeated sprinting.

A backpack load sharing model to evaluate lumbar and hip joint contact forces during shoulder borne and hip belt assisted load carriage

Musculoskeletal injuries of the lumbar spine occur frequently among military service members and are associated with heavy backpack loads. Musculoskeletal modeling and simulation facilitate biomechanical evaluation to compare different backpack designs. We developed a backpack attachment model that can be tuned to represent various load distributions between the torso and pelvis. We generated walking simulations to estimate muscle and joint contact forces of unloaded walking and while carrying 38 kg using shoulder-borne backpacks and hip belt-assisted backpacks for six U.S. Marines. Three-dimensional peak and average lumbar (L4-L5) and hip joint contact forces over the stance phase were compared between each load condition. Axial L4-L5 and axial and anterior hip joint contact forces were greater during both backpack conditions compared to the unloaded condition. Joint contact forces were similar between backpack conditions. Future studies incorporating additional participants, walking conditions, and backpack load distributions are suggested for further model development and backpack design evaluation.

Load Magnitude and Locomotion Pattern Alter Locomotor System Function in Healthy Young Adult Women

Introduction

During cyclical steady state ambulation, such as walking, variability in stride intervals can indicate the state of the system. In order to define locomotor system function, observed variability in motor patterns, stride regulation and gait complexity must be assessed in the presence of a perturbation. Common perturbations, especially for military populations, are load carriage and an imposed locomotion pattern known as forced marching (FM). We examined the interactive effects of load magnitude and locomotion pattern on motor variability, stride regulation and gait complexity during bipedal ambulation in recruit-aged females.

Methods

Eleven healthy physically active females (18–30 years) completed 1-min trials of running and FM at three load conditions: no additional weight/bodyweight (BW), an additional 25% of BW (BW + 25%), and an additional 45% of BW (BW + 45%). A goal equivalent manifold (GEM) approach was used to assess motor variability yielding relative variability (RV; ratio of “good” to “bad” variability) and detrended fluctuation analysis (DFA) to determine gait complexity on stride length (SL) and stride time (ST) parameters. DFA was also used on GEM outcomes to calculate stride regulation.

Results

There was a main effect of load (p = 0.01) on RV; as load increased, RV decreased. There was a main effect of locomotion (p = 0.01), with FM exhibiting greater RV than running. Strides were regulated more tightly and corrected quicker at BW + 45% compared (p < 0.05) to BW. Stride regulation was greater for FM compared to running. There was a main effect of load for gait complexity (p = 0.002); as load increased gait complexity decreased, likewise FM had less (p = 0.02) gait complexity than running.

Discussion

This study is the first to employ a GEM approach and a complexity analysis to gait tasks under load carriage. Reduction in “good” variability as load increases potentially exposes anatomical structures to repetitive site-specific loading. Furthermore, load carriage magnitudes of BW + 45% potentially destabilize the system making individuals less adaptable to additional perturbations. This is further evidenced by the decrease in gait complexity, which all participants demonstrated values similarly observed in neurologically impaired populations during the BW + 45% load condition.

Effect of foods on selected dynamic parameters of mandibular elevator muscles during symmetric incisal biting

The paper focuses on research that enables the relationship between food and selected mechanical parameters do be determined. The main aim of the study was to designate, depending on the food: (1) the work of a single muscle (i.e. masseter, medial pterygoid, temporalis), and (2) the energy balance of mandibular elevator muscles based on the dynamic patterns of muscles. In turn, the indirect goal was to determine: (1) the muscle contraction, and (2) the average muscle contraction velocity based on the specified kinematic parameters, i.e. incisal biting velocity and incisal biting time. A hybrid model, consisting of a phenomenological model of the masticatory system and a behavioural model of incisal biting, was used in the calculations. The phenomenological model was based on an anatomically and physiologically normal mandible and healthy muscles, while the behavioural model was represented by the dynamic patterns of food. Calculations showed that muscle force is an important, but not the only, parameter that enables the quantitative and qualitative assessment of the functioning of the mandibular elevator muscles during symmetric incisal biting. Based on the obtained results, it can be stated that the dynamic patterns of muscles are a very important parameter, because on their basis, among others, muscle contraction, contraction time, work, and energy can be determined. The conducted calculations and analyses showed that the above-mentioned parameters depend on the mechanical properties of food (the dynamic patterns of food).

Load carriage magnitude and locomotion strategy alter knee total joint moment during bipedal ambulatory tasks in recruit-aged women

Knee osteoarthritis (OA) is prevalent among female soldiers, resulting in limited duty and long term adverse ambulatory effects. A proposed mechanism to the development of knee OA is the assiduous execution of load carriage tasks. Soldiers are often required to maintain a walking gait with load at velocities beyond their gait transition velocity (GTV) known as forced marching. The primary aim of this investigation is to determine the interactive effects of load magnitude and locomotion pattern on relative knee total joint moment (KTJM) in healthy recruit-aged women. The secondary aims are to determine knee total joint moment limb differences and to determine the interactive effect of load magnitude and locomotion pattern on the percent contributions of each plane of motion moment. Individuals were tasked with running and forced marching at 10% above their GTV at body weight (BW) and with an additional 25% and 45% of their BW. KTJM was analyzed at two specific gait events of heel-strike and mid-stance. At heel-strike, forced marching exhibited greater KTJM compared to run for all load conditions but running had greater KTJM than forced marching at mid-stance. The forced marching pattern exhibited larger KTJM for the dominant limb at both gait events compared to running. Lastly, at mid-stance the knee adduction moment percent (KAM%) contribution was greater for forced marching compared to running. The forced marching pattern demonstrates joint kinetics that may be more deleterious with prolonged exposure. Likewise, forced marching induced KAM% similar to those already suffering from knee OA.

EFFECTS OF SINGLE CROUCH WALKING GAITS ON FATIGUE DAMAGES OF LOWER EXTREMITY MAIN MUSCLES

Single crouch walking gait (SCWG) is one of the main walking gaits when one of the legs is injured. However, the research on movement biomechanical characteristics (MBC) of lower extremity in SCWG has not been reported. So, the aim of this study is to analyze kinematics and main muscle fatigue damages of lower extremity in SCWG. Gaits data were collected with functional assessment biomechanics (FAB) system which applies the real-time wireless gait phase detection system, the movement function relations of joints of lower extremity were obtained by fitting the collected data in normal walking gait (NWG) and SCWG with Fourier series, the fitted movement functions were input to 3D human musculoskeletal model as driving functions for human movement to analyze the differences of MBC between SCWG and NWG. Finally, the muscle contractions were used to evaluate muscle fatigue damage. Compared with NWG, the result shows that the movement range of the joint angles of lower extremity are reduced in SCWG, the change law of hip internal/external rotation angle (IERA) has a significant difference, and the change laws of other joint angles are similarly between SCWG and NWG. The muscle contractions of Gluteus maximum (GMAX) 2, Gluteus meddle (GMED) 1, GMED2, Iliacus (ILI), Rectus femoris (RFEM), Soleus (SOL), Gastrocnemius (GAS) and Vastus lateralis (VLAT) are significantly larger in SCWG than in NWG (except GlutMed2 which is about 20–40% and VLAT which is about 63.8–76.1% of gait cycle), namely, these muscles easily cause muscle damages in SCWG. The contraction change of Adductor magnus (AMAG) is dispersed, so AMAG is prone to muscle fatigue in SCWG. The study results will fill in the gaps in the MBC of lower extremity in SCWG and provide data for Rehabilitation Medical Technology (RMT) and development of rehabilitation equipment of lower extremity.