Journal Of Applied Biomechanics[JOURNAL]
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200 papers
The Dynamic Gait Index Does Not Sufficiently Capture the Ability to Adapt Walking Under Dual-Task Conditions.
Mitchell D, Wade FE
J Appl Biomech · 2026 Mar · PMID 41921950 · Publisher ↗
Walking in daily life requires the performance of multiple tasks simultaneously, such as walking and talking. Thus, dual-task performance is critical in assessments of functional gait and mobility. The Dynamic Gait Index...
Walking in daily life requires the performance of multiple tasks simultaneously, such as walking and talking. Thus, dual-task performance is critical in assessments of functional gait and mobility. The Dynamic Gait Index (DGI) is used widely to evaluate walking capacity, but its ability to capture changes in walking function while under cognitive load is unclear. In this study, we examined whether DGI scores are associated with the dual-task cost (DTC) of walking performance in adults (aged 41 [19]) across a spectrum of walking abilities. Participants completed treadmill walking trials under single- and dual-task (visual-verbal Stroop) conditions. Significant dual-task effects were found across all primary walking measures, including step length, step width, double support time, and trailing limb angle, with large interindividual variability. Correlations between DGI score and DTC were not observed. These findings suggest that DGI and DTC capture different aspects of walking function. While the DGI may be useful for identifying gross impairments, DTC is more sensitive to subtle changes in walking function. Integrating dual-task assessments into existing evaluations of walking function may mobility screening, particularly in aging and preclinical populations.
Changes in Biomechanical Risk Factors for Injury Across Normalized Running Speeds in Healthy Collegiate Cross-Country Runners.
Brindle RA, Foch E, Smoliga JM … +3 more , Westbrook AE, Hegedus EJ, Ford KR
J Appl Biomech · 2026 Mar · PMID 41887194 · Publisher ↗
Cross-country runners' risk for injury is high in-season potentially due to changes in biomechanics during prescribed fast running speeds and competitions. The purpose of this study was to determine if biomechanics assoc...
Cross-country runners' risk for injury is high in-season potentially due to changes in biomechanics during prescribed fast running speeds and competitions. The purpose of this study was to determine if biomechanics associated with overuse knee and lower leg injury during running change similarly across speeds between female and male collegiate cross-country runners. Sixteen collegiate cross-country runners (8 females) participated. A self-selected running speed was entered into regression equations to determine treadmill speeds for the conditions: recovery (∼9% slower), threshold (∼25% faster), interval (∼36% faster), and repetition (∼50% faster). Three-dimensional lower-extremity biomechanics were collected during running. Dependent variables were analyzed via mixed-model analysis of variance and pairwise post hoc tests. Both peak rearfoot angle increased (P = .005, Cohen's f = 0.84) and rearfoot excursion increased (P = .002, Cohen's f = 0.88) with the conditions' treadmill speed. Peak knee adduction angle was greater in females compared with males (P = .032, Cohen's f = 0.67) during: recovery, easy, threshold, and interval conditions. Increases in running speed affected joint kinematics and kinetics similarly between groups. Generally, similar running biomechanics observed between females and males may indicate that faster training speeds could accentuate the contribution of rearfoot eversion to lower leg overuse injury.
Walk This Way: Crocs and the Impact of Heel Strap Utilization on Overground Walking Performance and Lower Limb Joint Kinematics.
Saucedo F, Ambati VNP, Teles Santos TR
J Appl Biomech · 2026 Mar · PMID 41887191 · Publisher ↗
Gait kinematics undergo significant alterations stemming from shoe type that can enhance performance or result in musculoskeletal injuries that impact daily living. Crocs surge to mainstream consumers, along with their p...
Gait kinematics undergo significant alterations stemming from shoe type that can enhance performance or result in musculoskeletal injuries that impact daily living. Crocs surge to mainstream consumers, along with their presence throughout other industries, begs the question of the impact of this shoe on walking performance and kinematics. This study examined the impact of Crocs with and without heel strap on walking performance and lower body kinematics. Thirty-one participants completed 3 walking trials at self-selected pace for each condition: control (CON): socked; sports mode: Crocs with heel strap; and comfort mode: Crocs without heel strap. Inertial measurement units were used to calculate sagittal kinematics of the hip, knee, and ankle. Sports mode significantly improved walking velocity and stride length compared with comfort mode and control conditions while walking. Hip and knee angles were different only when comparing shod conditions to the control condition. Ankle dorsiflexion during stance, range of motion during the swing phase, and plantarflexion during toe-off differed significantly between the sports mode and comfort mode conditions and provide insight to the contributions of heel straps to shoe fit, walking performance, and joint mechanics. The ankle kinematics suggest that when worn without a heel strap, Crocs negatively impact ankle mechanics and impact lower limb kinematics.
Precise Quantification of the Onset and Cessation of Flexion-Relaxation in the Erector Spinae Muscles: A Comparison of 1 Versus 2 Inertial Motion Sensors.
Hyeon Kang S
J Appl Biomech · 2026 Mar · PMID 41860793 · Publisher ↗
Precise quantification of the lumbar flexion-relaxation phenomenon can provide a better understanding of the load transfer between active and passive tissues and its implications for spinal stability. This study aimed to...
Precise quantification of the lumbar flexion-relaxation phenomenon can provide a better understanding of the load transfer between active and passive tissues and its implications for spinal stability. This study aimed to compare the precision of instantaneous angles using 1 versus 2 inertial motion sensors to determine the deactivation (electromyography [EMG]-off) and reactivation (EMG-on) of left and right erector spinae muscles during trunk flexion and extension. Electromyography and kinematic data were collected from 12 participants who performed 20 slow, controlled trunk flexion-extension motions. The angle derived from 1 motion sensor was the pitch angle of the T12 sensor, and the angle derived from 2 sensors was the difference between the pitch angles of the T12 and S1 sensors. The EMG-off (or EMG-on) angle was defined as the angle at which unilateral erector spinae muscle activity dropped below (or exceeded) 3 times the muscle activity recorded at full trunk flexion during trunk flexion and extension. Results revealed that absolute and relative variability in 20 EMG-off and EMG-on angles were greater when measured with 1 inertial motion sensor than with 2 sensors (P ≤ .003), suggesting that using 2 sensors can improve the precision of flexion-relaxation phenomenon determination compared with using 1 sensor.
Effects of Sex and Anatomical Location on Muscle and Adipose Thickness Surrounding the Proximal Femur: Implications for Fall-Related Impact Dynamics.
Tondat AM, Mourtzakis M, Laing AC
J Appl Biomech · 2026 Jun · PMID 41850270 · Publisher ↗
Trochanteric soft tissues have significant effects on fall-related hip fracture risk; however, little is known about their composition and spatial distribution. Accordingly, this study determined (1) the influence of sex...
Trochanteric soft tissues have significant effects on fall-related hip fracture risk; however, little is known about their composition and spatial distribution. Accordingly, this study determined (1) the influence of sex and anatomical location on muscle thickness, adipose thickness, and total soft tissue thickness surrounding the proximal femur; and (2) the effects of sex- and location-specific soft tissue thickness on predicted fall-related hip impact forces. Ultrasound was used to measure muscle thickness, adipose thickness, and total soft tissue thickness at 12 locations surrounding the proximal femur in 25 young adult participants. Fall-related hip impact forces were predicted with a mass-spring model, accounting for force attenuation by soft tissues, at 2 common impact sites. The data demonstrated that tissue thickness and impact forces were significantly influenced by sex and anatomical location. Males had more muscle, less adipose, less total soft tissues, less force attenuation, and higher impact forces than females. Total soft tissue thickness and muscle thickness were lowest over the lateral femur, while adipose thickness was lowest over the anterolateral femur. Force attenuation was higher while impact forces were lower at the posterolateral impact site. The data support that the accuracy of hip impact models could be improved by incorporating sex-, location-, and composition-specific soft tissue thickness measures.
The Effect of the Lateral Wedge Insoles on Cumulative Loads and Changes in Physical Activity of Patients With Knee Osteoarthritis.
Xu C, Ishii Y, Kamei G … +10 more , Nekomoto A, Hashizume T, Okamoto S, Okinaka R, Zhu K, Iwamoto Y, Nakashima Y, Ishikawa M, Takahashi M, Adachi N
J Appl Biomech · 2026 Jun · PMID 41838450 · Publisher ↗
Knee pain in patients with knee osteoarthritis leads to decreased physical activity. The knee adduction moment impulse is closely related to pain, multiplied by the number of steps per day, reflecting the cumulative knee...
Knee pain in patients with knee osteoarthritis leads to decreased physical activity. The knee adduction moment impulse is closely related to pain, multiplied by the number of steps per day, reflecting the cumulative knee adductor load (CKAL). The intervention of lateral wedge insole (LWI) can relieve pain by reducing the CKAL, but changes in physical activity have not been investigated. This study aimed to determine the effect of the LWI on the CKAL and changes in physical activity. Twenty-one patients with knee osteoarthritis were enrolled in our study. The knee adduction moment impulse was estimated by a VICON system without LWI (baseline) and with LWI immediately (T0) at the initial visit and 3 months after intervention (T1). An accelerometer was worn for 8 days to monitor daily steps and activity. The physical activity was performed at baseline and T1. Pain was evaluated at baseline, T0, and T1. Pain and CKAL were reduced significantly after the intervention of the LWI. The knee adduction moment impulse at T0 and T1 was reduced compared with the baseline. There was no significant change in daily steps. However, physical activity significantly decreased in terms of the total duration of activity, standing, and periods of standing and walking.
Position of Swing-Phase Foot Relative to Stance-Phase Foot at Minimum Toe Clearance: The Effect of Walking Speed.
Gomez NG, Gomez MA, MacWilliams BA … +1 more , Foreman KB
J Appl Biomech · 2026 Jun · PMID 41838448 · Publisher ↗
Minimum toe clearance (MTC) location relative to the stance-phase foot, as well as how this location changes with walking speed, helps in better understanding the circumstances when MTC is most relevant. This study helps...
Minimum toe clearance (MTC) location relative to the stance-phase foot, as well as how this location changes with walking speed, helps in better understanding the circumstances when MTC is most relevant. This study helps define where MTC occurs for the swing-phase foot in relation to the stance-phase foot. Gait speed was assessed also to determine its effect on this relative positioning. 3D lower body gait data were collected from 14 barefoot participants (age: 8-14 y). Participants ambulated at slow, self-selected, and fast gait speeds. At all speeds, MTC was found to occur closer to the tip of the hallux rather than to the heel of the stance-phase foot. At slow gait speeds, the MTC was 70.2% from the heel. For the self-selected and fast speeds, the MTC was 113.6% and 98.8% from the heel, respectively. Though the location changed, the vertical height of the swing-phase foot at MTC did not change significantly as a function of gait speed. These results indicate that the location of MTC is significantly impacted by the placement of the stance-phase foot as well as walking speed. These factors can play a role in assessing the risk of tripping when an unexpected trip hazard is present.
Integrating Athlete Perspectives and Head Kinematics in Youth American Football.
Marks ME, Holcomb TD, Miles CM … +4 more , Flashman LA, Stitzel JD, Moore JB, Urban JE
J Appl Biomech · 2026 Jun · PMID 41838431 · Publisher ↗
The objectives of this study were to examine youth football athletes' individual head acceleration event (HAEs) exposure, explore athletes' perspectives and experiences playing youth football, and investigate relationshi...
The objectives of this study were to examine youth football athletes' individual head acceleration event (HAEs) exposure, explore athletes' perspectives and experiences playing youth football, and investigate relationships between their perspectives and HAE exposure. Thirteen middle-school-aged football athletes wore instrumented mouthpieces to measure HAEs for 1 season and participated in a one-on-one interview, discussing motivations, mental focus, safety, and perceptions of contact. Kinematic data were integrated with qualitative data using triangulation to examine relationships between athlete perspectives and HAEs. Two thousand six hundred seventy-one true-positive HAEs were collected and analyzed. Topics discussed in interviews included aspirations, mental focus, potential for injury, and perceptions of contact. Athletes with the greatest HAE frequency discussed wanting to advance to higher levels of football (eg, college). Several athletes expressed an affinity for contact, many of whom had more HAEs per session than other athletes; however, some athletes disliked the risk of injury in football. Athletes reported that hits to the head felt the hardest, consistent with greater magnitudes measured among head impacts compared with body impacts. Athletes' perceptions of collisions and safety topics may inform our understanding of factors that influence HAE exposure in football and help guide identification of individual-level targets to reduce exposure and concussion risk.
Individuals With Knee Osteoarthritis and Symmetrical Total Joint Moment Exhibit Bilateral Gait Characteristics Associated With Osteoarthritis.
Halliwell C, Budarick A, Astephen Wilson J … +3 more , Rutherford D, Hannigan M, Moyer R
J Appl Biomech · 2026 Jun · PMID 41765012 · Publisher ↗
Interlimb asymmetries may influence contralateral knee osteoarthritis (OA) progression, yet research remains unclear. This study examined whether patient-reported outcomes and knee biomechanics differ between individuals...
Interlimb asymmetries may influence contralateral knee osteoarthritis (OA) progression, yet research remains unclear. This study examined whether patient-reported outcomes and knee biomechanics differ between individuals with knee OA exhibiting symmetrical versus asymmetrical knee loading. Forty-three individuals with knee OA were dichotomized into symmetrical (≤14% asymmetry; n = 19) and asymmetrical (>14% asymmetry; n = 24) groups based on total joint moment symmetry indices. Participants completed the Knee Injury and Osteoarthritis Outcome Score and Intermittent and Constant Osteoarthritis Pain questionnaires. Three-dimensional kinematics and kinetics were collected during walking at a self-selected speed. Independent t tests and statistical parametric mapping examined between-group differences in patient-reported outcomes and biomechanical measures. Individuals with symmetrical knee loading had worse Knee Injury and Osteoarthritis Outcome Score activities of daily living scores (P = .041) than those with asymmetrical loading. Individuals with symmetrical knee loading exhibited less knee extension moment during late stance (P = .031) and lower knee adduction moment range in their affected knee compared with asymmetrical loaders. Individuals with symmetrical knee loading walked with lower knee flexion angles (P = .011), less midstance unloading (P = .011), and lower peak knee flexion moment (P < .001) in their contralateral knee compared with asymmetrical loaders. Symmetrical knee loading was associated with affected and contralateral knee biomechanics that were consistent with more severe knee OA and worse functional outcomes.
Comparison of 3-Dimensional Thorax and Upper-Extremity Joint Kinematics During Manual Wheelchair Propulsion Using Marker-Based and Markerless-Based Biomechanical Models.
Moon J, Tran DF, Lopez JR … +1 more , Hanks MM
J Appl Biomech · 2026 Jun · PMID 41765004 · Publisher ↗
Marker-based motion analysis is the standard for evaluating human movement, yet it is time-intensive and requires extensive technical knowledge. Markerless-based motion analysis can simplify and expedite clinical biomech...
Marker-based motion analysis is the standard for evaluating human movement, yet it is time-intensive and requires extensive technical knowledge. Markerless-based motion analysis can simplify and expedite clinical biomechanics research, but its utility with unique populations, like manual wheelchair users, remains understudied. The purpose of this study was to compare 3-dimensional thorax and bilateral upper-extremity joint kinematics during manual wheelchair propulsion between criterion-standard marker-based and novel markerless-based biomechanical models. Fifteen young adult, manual wheelchair users propelled on a stationary roller while synchronized optical motion analysis cameras recorded 3-dimensional marker trajectory and 2-dimensional video data simultaneously. Statistical parametric mapping was used to evaluate kinematic differences between models. Pearson correlation and average root mean square were also used to explore the relationships and the magnitudes of observed differences between models. Significant differences in thorax and upper-extremity joint kinematics were observed between the models (P < .05). Joint angle differences varied in magnitude from 3.6° to 36.6° and joint center differences varied in magnitude from 0.4 to 2.4 cm. Differences were dependent upon the joint and anatomical plane/axis. Despite some observed limitations, markerless-based motion analysis may be a useful clinical research tool to evaluate thorax and upper-extremity kinematics during wheelchair mobility.
Do Pitching Biomechanics Differ Between Windup and Stretch Pitching Deliveries From a Dirt Surface Mound in College Baseball Pitchers?
Escamilla RF, Slowik JS, Imamura R … +4 more , Thompson IS, Asuncion R, Aguinaldo AL, Fleisig GS
J Appl Biomech · 2026 Jun · PMID 41722544 · Publisher ↗
It is unknown how pitching biomechanics in college baseball pitchers differ between windup and stretch pitching deliveries from a dirt surface mound. The purpose was to assess differences in shoulder and elbow kinetics a...
It is unknown how pitching biomechanics in college baseball pitchers differ between windup and stretch pitching deliveries from a dirt surface mound. The purpose was to assess differences in shoulder and elbow kinetics and pitching kinematics in college pitchers between windup and stretch pitching deliveries from a dirt surface mound. Eighteen college pitchers pitched from a dirt surface mound using windup and stretch pitching deliveries. All pitchers were tested using a 240-Hz, 12-camera motion analysis system, and 28 kinematic and 7 kinetic parameters were calculated. Paired within-subjects t tests (P < .05) were used to assess biomechanical differences between windup and stretch deliveries. Maximum shoulder horizontal adduction torque, maximum shoulder anterior force, maximum lead knee height, ball velocity at ball release, forward trunk tilt at ball release, maximum upper trunk angular velocity, maximum elbow extension angular velocity, and maximum shoulder internal rotation angular velocity were all significantly greater using a windup delivery compared with a stretch delivery. Pelvic drift at maximum lead knee height was the only parameter that was significantly greater in a stretch delivery compared with a windup delivery. Nine of the 35 (26%) biomechanical parameters were significantly different between windup and stretch deliveries. Shoulder injury risk may be slightly lower using a stretch delivery compared with a windup delivery due to overall lower shoulder kinetics during the stretch delivery.
Relationship Between Decomposition of Surface Electromyography Signals and Force Production: Analyzing Recovery From Intense Exercise.
Sousa MV, Priego-Quesada JI, Becker KM … +3 more , Fonseca P, Ervilha UF, Vilas-Boas JP
J Appl Biomech · 2026 Jun · PMID 41713462 · Publisher ↗
This study investigated the relationship between neuromuscular (motor unit action potential amplitude [MUAP], firing rate, recruitment threshold), biomechanical (force loss), physiological (skin temperature), and percept...
This study investigated the relationship between neuromuscular (motor unit action potential amplitude [MUAP], firing rate, recruitment threshold), biomechanical (force loss), physiological (skin temperature), and perceptual (delayed onset of muscle soreness) markers following an intense knee exercise protocol. Eleven participants performed 2 maximal isometric and 5 concentric-eccentric knee contractions. Assessments were made immediately postexercise (0 h), at 24 hours and 48 hours after intense knee exercise protocol. Electromyography signal decomposition and skin temperature were measured during the protocol, while delayed onset of muscle soreness was evaluated at 24 and 48 hours. A reduction in force production (isometric, dynamic, and Work) was observed at all postexercise time points. Delayed onset of muscle soreness increased at 24- and 48-hour postexercise compared to Pre-exercise. At 0 hours, a positive, moderate correlation was observed between dynamic force loss and MUAP of the vastus lateralis (VL). Two moderate positive correlations were observed between firing rate of rectus femoris and minimum temperature, and between the recruitment threshold of VL and mean temperature. At 24-hour postexercise, a positive moderate correlation was observed between dynamic peak torque and MUAP of VL. These findings suggest that full recovery of force is not achieved at 48-hour postexercise, with MUAP of VL playing a key role in muscle recovery.
Greater Ankle Plantar Flexor Work Is Predictive of Better Running Economy on Steep Uphill Grades.
Robinson RM, Hahn ME
J Appl Biomech · 2026 Apr · PMID 41713453 · Publisher ↗
The purpose of this study was to determine the influence of lower extremity joint kinetics and muscle strength on running economy (RE) over level ground, 5% and 10% grades. Twenty-seven recreational runners (14 females,...
The purpose of this study was to determine the influence of lower extremity joint kinetics and muscle strength on running economy (RE) over level ground, 5% and 10% grades. Twenty-seven recreational runners (14 females, age: 33.7 [12.8] y, mass: 70.2 [12.5] kg, height: 175.9 [9.1] cm) completed laboratory-based RE, biomechanics, and isokinetic dynamometry testing. Linear regression analyses were used to determine the effect of lower extremity joint work, stiffness, and strength on RE for each grade. Greater ankle plantar flexor work was predictive of better economy when running on the 10% grade (β = -3054.56; P = .013), but not the level ground or 5% grade (P > .05). No other joint work, stiffness, or strength factors were related to RE. A secondary analysis explored the relationship of training factors to RE, demonstrating better 10% grade RE (P = .015) and greater ankle work (P = .048) in trail runners compared with road runners. The results of this study suggest that targeting the energy generation capacity of the plantar flexors may be worthwhile for improving uphill RE. Trail running may lead to specific physiological and biomechanical adaptations that are beneficial to performance.
Evaluating the Agreement of Markerless Motion Capture for Joint Angle Estimation in a Constrained Hallway Setting Compared With a Traditional Laboratory Setting.
Ruder M, Di Bacco VE, Outerleys J … +7 more , Malek M, Laende E, Gafoor F, Madden K, Adili A, Deluzio K, Kobsar D
J Appl Biomech · 2026 Jun · PMID 41679295 · Publisher ↗
Gait analysis is a valuable approach for understanding human movement, but the space and setup requirements of traditional marker-based systems can limit their use outside specialized laboratories. Markerless motion capt...
Gait analysis is a valuable approach for understanding human movement, but the space and setup requirements of traditional marker-based systems can limit their use outside specialized laboratories. Markerless motion capture may provide a more flexible option, though its agreement in constrained environments compared with traditional spaces is not well established. This study compared a 10-camera markerless system deployed in a hallway with a traditional 8-camera laboratory setup. Twenty-five healthy adults (15 females, 10 males; age 34 [16] y) completed quiet standing, 60 seconds of self-selected walking, and 5-repetition sit-to-stand tasks at both sites on the same day. Three-dimensional pose estimates were processed to calculate alignment during standing, lower-limb joint kinematics during walking, and trunk flexion during sit-to-stand. Agreement within and between sites was assessed using Pearson correlations, root mean square error, Bland Altman limits of agreement, and intraclass correlation coefficients. Standing and walking outcomes showed excellent agreement (intraclass correlation coefficients ≥ .97; root mean square error < 2.3°; mean differences < 1.1°). Sit-to-stand was more variable (limits of agreement 12°-20°) but remained highly reliable (intraclass correlation coefficients > .96). These findings indicate that a constrained markerless setup can yield kinematic data comparable to a laboratory arrangement, suggesting potential for broader use of markerless approaches in diverse environments.
The Association Between Foot-Ankle Mechanical Leverage and Instability During Walking in Older and Younger Adults.
Gray AJ, Takahashi KZ, Franz JR
J Appl Biomech · 2026 Apr · PMID 41638195 · Publisher ↗
Falls in older adults are a serious public health concern with physical and economic consequences that reduce independence and quality of life. Older adults have morphological changes at the foot and ankle that may disru...
Falls in older adults are a serious public health concern with physical and economic consequences that reduce independence and quality of life. Older adults have morphological changes at the foot and ankle that may disrupt foot neuromechanics and the foot's ability to regulate mechanical leverage and balance during walking. This study quantified age and walking speed effects on mechanical leverage of the foot and ankle, as well as the extent to which interindividual differences in foot-ankle leverage correlated with whole-body balance metrics-the latter during habitual walking and in response to 2 contexts of walking balance perturbations. We found no age effect on peak external moment arms due to ground reaction forces. However, older adults exhibited smaller peak ankle moments, larger ranges of frontal plane whole-body angular momentum, larger anterior-posterior margin of stability, and larger perturbation-induced changes in whole-body angular momentum than younger adults. We also report the first evidence that better foot-ankle leverage during habitual walking correlated with larger margins of stability and smaller ranges of whole-body angular momentum. This study was a first step in understanding the relationship between foot-ankle mechanical leverage and whole-body balance.
Differences in Treadmill-Based Gait Analysis Based on 3 Methods for Comfortable Walking Speed Selection in Healthy Adults.
Wischhoff P, Riemens MMR, Meijer K … +1 more , de Rooij IJM
J Appl Biomech · 2026 Apr · PMID 41570813 · Publisher ↗
During gait analysis, the walking speed of the individual should reflect the walking speed in everyday life. This study compared spatiotemporal and kinematic parameters between 3 conditions of selecting walking speed for...
During gait analysis, the walking speed of the individual should reflect the walking speed in everyday life. This study compared spatiotemporal and kinematic parameters between 3 conditions of selecting walking speed for treadmill-based gait analysis in healthy adults. We hypothesized that gait parameters collected during self-selected treadmill walking differ from those collected when walking at matched overground speed and self-paced speed. Forty-two healthy participants (40.0 [12.7] y; 16 males) walked on a treadmill in a virtual environment in 3 conditions: speed matching overground speed from the 10-m walk test, self-paced walking, and speed selected by the participant. Spatiotemporal and kinematic parameters were collected using motion capture analysis. Results showed significant differences in walking speed, step length, stride length, step time, stride time, stance time, cadence, peak extension angle of the hip, and peak plantar flexion angle of the ankle between the self-paced condition and matched overground speed (P < .05). These differences in gait parameters were likely due to variations in speed between the 2 conditions. No significant differences were found between treadmill-selected and matched overground speed or self-paced condition. These findings suggest that letting the participant decide their comfortable walking speed is appropriate for speed selection in gait analysis.
Adherence to Simple Spring-Mass Mechanics During Submaximal Running in Individuals With Unilateral Transfemoral Amputation.
Tang YW, Murai A, Hobara H
J Appl Biomech · 2026 Apr · PMID 41569866 · Publisher ↗
Lower extremities adhering to the spring mechanics proposed by the spring-loaded inverted pendulum (SLIP) model during running are regarded as a form of running-gait optimization among runners. We examined the degree of...
Lower extremities adhering to the spring mechanics proposed by the spring-loaded inverted pendulum (SLIP) model during running are regarded as a form of running-gait optimization among runners. We examined the degree of adherence between experimental and SLIP model-predicted vertical ground reaction force (vGRF) in individuals with unilateral transfemoral amputation. Nine individuals with unilateral transfemoral amputation performed running trials at 6 different speeds on an instrument treadmill. The trials were set at 30% to 80% of their maximum speeds with a 10% increment. The experimental vGRF collected was compared with SLIP model-predicted vGRF. The degree of adherence was calculated using the R2 goodness-of-fit statistics. The experimental vGRF of the affected limbs exhibited a significantly higher degree of adherence than unaffected limbs. There were no significant differences in the degree of adherence between different speed trials for either limb. This finding indicates that running-specific prostheses exhibit mechanical behavior that is consistent with SLIP mechanics, whereas the unaffected limb relies on compensatory, non-SLIP-like strategies. Furthermore, the results suggest that the interaction of running-specific prostheses with other prosthetic components and the residual limb enables the preservation of running mechanics across a range of speeds, thereby supporting the application of SLIP-based modeling to the affected limb.
People With Marfan Syndrome Utilize an Ankle Dominant Strategy to Perform the Sit-to-Stand Task.
Pol JM, Jacobs MV, McLouth CJ … +3 more , Gaffney BMM, Sheppard M, Samaan MA
J Appl Biomech · 2026 Apr · PMID 41569862 · Full text
Marfan syndrome (MFS) is a connective tissue disorder caused by structural changes in fibrillin-1 and is associated with muscle weakness and joint pain. The understanding of lower extremity (LE) joint mechanics associate...
Marfan syndrome (MFS) is a connective tissue disorder caused by structural changes in fibrillin-1 and is associated with muscle weakness and joint pain. The understanding of lower extremity (LE) joint mechanics associated with joint pain in people with MFS is limited. The goal of this study was to assess LE joint mechanics during the sit-to-stand (STS) task in people with MFS compared with asymptomatic controls. Sixteen people with MFS and 16 sex- and body mass index-matched controls were tested in this study. All participants performed the STS task at a self-selected speed. Peak LE joint extensor moments, moment impulses, moment durations, time to task completion, total support moment (TSM), and each joint's contribution to the TSM were evaluated. People with MFS took longer to perform the task and exhibited lower peak knee extensor moments and higher peak ankle plantar flexor moments compared with controls. Higher LE joint extensor moments impulses and moment durations were observed in people with MFS. People with MFS performed the STS task using a higher TSM with higher ankle contributions to the TSM. People with MFS exhibit altered LE joint mechanics during the STS task and utilize a more ankle joint dominant strategy.
Comparative Analysis of Muscle Coordination Patterns During Squatting in Trained and Untrained Individuals.
Kim Y
J Appl Biomech · 2026 Apr · PMID 41569842 · Publisher ↗
Squatting, a closed-kinetic chain exercise, requires the complex coordination of multiple muscles. However, the differences in muscle coordination patterns between individuals with varying levels of exercise proficiency...
Squatting, a closed-kinetic chain exercise, requires the complex coordination of multiple muscles. However, the differences in muscle coordination patterns between individuals with varying levels of exercise proficiency remain unclear. This study aimed to compare muscle coordination patterns during the squat exercise between trained and untrained individuals. Sixteen participants, classified into trained and untrained groups, performed 20 repetitive squats while both motion capture and electromyography data were recorded. Muscle synergy analysis was employed to identify muscle coordination patterns, and cluster analysis was used to determine preferred muscle synergies within each group. The findings indicate that trained individuals exhibit muscle synergies characterized by the coactivation of trunk and leg muscles near the bottom position of the squat. By contrast, untrained individuals primarily show coactivation of leg muscles only. Motion analysis further revealed that trained participants maintained a more upright posture during this phase compared with untrained participants. The distinct muscle synergies between trained and untrained individuals suggest the importance of coordinated trunk and leg muscle activation in maintaining postural control near the bottom position, where the movement transitions from descent to ascent. These insights can inform training strategies to promote effective trunk-leg coordination and postural control in untrained individuals.
A Functional Sensor-to-Segment Calibration Method Reduces the Effects of Varied Sensor Placement on Estimates of Segment Angular Excursion.
Mihy JA, Wagatsuma M, Cain SM … +1 more , Hafer JF
J Appl Biomech · 2026 Apr · PMID 41569824 · Full text
To collect reliable data, it is important to determine how inertial measurement unit (IMU) sensor placement affects measurements of segment motion. We aimed to determine the extent to which a functional sensor-to-segment...
To collect reliable data, it is important to determine how inertial measurement unit (IMU) sensor placement affects measurements of segment motion. We aimed to determine the extent to which a functional sensor-to-segment calibration method minimizes the effect of variations in sensor placement on IMU-derived segment angular excursions. Twenty healthy adults walked while wearing 3 IMUs placed on each of the pelvis, thigh, shank, and foot. Differences in estimated segment angular excursions between sensor placements were compared between an assumed sensor-to-segment calibration and 2 versions of a walking-based functional sensor-to-segment calibration. The performance of the functional calibration methods varied. The shank had the greatest difference in root mean square difference between methods (15° for assumed, 1.5° for functional calibration), but the pelvis and thigh did not have significant differences in root mean square difference between assumed and functional calibrations. Mean root mean square differences for angular excursion between sensors were <5° for most comparisons for assumed and functional calibrations. Functional calibration reduced between-subject variance in intersensor differences for all segments. Functional calibration can minimize the effect of variations in IMU sensor placement, but care should be taken to select sensor placements that minimize soft-tissue artifact (eg, anterior thigh).
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