The influence of experience on knee mechanics during side-step cutting in females

BACKGROUND: It is thought that female athletes with limited experience in a sport perform athletic maneuvers differently than their more experienced counterparts, and that they do so in a manner that places them at greater risk for injury. The purpose of this study was to evaluate the influence of athletic experience on knee mechanics during the execution of a side-step cutting maneuver in young female athletes. METHODS: Three-dimensional kinematics, ground reaction forces and electromyographic activity (surface electrodes) were recorded during the early deceleration phase of side-step cutting in 30 high school females (15 experienced, 15 novice). Group differences in knee joint kinematics, peak moments, net joint moment impulse and average muscle activation were evaluated. FINDINGS: No significant group differences were found in knee kinematics. When compared to experienced females, novice females demonstrated significantly smaller flexor, adductor, and internal rotator peak moments and smaller net joint moment impulse in all three planes at the knee. No group differences were found for average EMG; however, novice athletes had significantly greater co-contraction at the knee. INTERPRETATION: The finding of smaller knee moments and greater muscle co-contraction in the novice group suggests that these athletes may adopt a protective strategy in response to a relatively unfamiliar task. In addition, these results suggest that increased moments at the knee emerge with experience, indicating that more skilled athletes may be at greater risk for anterior cruciate ligament (ACL) injury.     

Knee joint kinematics, kinetics and muscle co-contraction in knee osteoarthritis patient gait

Background

Compared to matched controls, knee osteoarthritis patients walk with altered, kinematics, kinetics and muscle activity. Studies of osteoarthritis patient gait have focused on individual measures, and findings from these studies differ due to differences in patient levels of disability and age. Therefore, aims of this study were to examine kinematic, kinetic and muscle co-contraction gait variables within a single osteoarthritis patient group, and to determine if alterations in these variables are related to pain, symptom and function measures.

Methods

Thirty asymptomatic controls and 54 patients with radiographic evidence of knee osteoarthritis participated. Self-perceived measures of pain and symptoms, and gait (knee joint angles, moments and muscle co-contraction) were analysed and compared.

Findings

Osteoarthritis patients had greater self-perceived pain and symptoms on the questionnaires. Gait differences in the knee osteoarthritis patients were greater knee flexion at heel strike and during early stance along with reductions in the peak external knee extension moment in late stance. Co-contraction ratios highlighted greater lateral muscle activation in osteoarthritis patients, which were correlated with the magnitude of their adduction moments. Larger adduction moments were related to lower self-perceived pain and symptoms.

Interpretation

Osteoarthritis patients use predominantly lateral muscle activation during stance which may aid in stabilising the external knee adduction moment. Kinematic alterations in knee osteoarthritis patient gait occur without alterations in knee joint moments. Our results also suggest that adduction moments are lowered to reduce the patients’ pain and symptoms.     

Influence of gender on hip and knee mechanics during a randomly cued cutting maneuver

Objective. To investigate gender differences in three-dimensional hip and knee joint mechanics in collegiate athletes during a randomly cued cutting maneuver.

Design. Three-dimensional kinematics and kinetics were collected on 24 collegiate soccer players (12 females and 12 males) while each performed the cutting maneuver. In order to create a randomly cued condition, subjects were signaled by a lighted target board that directed them to perform one of three tasks. Hip and knee joint mechanics were compared between genders using one-tailed t-tests.

Background. Female athletes have an anterior cruciate ligament injury rate that is larger than their male counterparts. Gender differences in hip and knee joint mechanics during a randomly cued cutting maneuver have not been previously reported.

Methods. Five randomly cued cutting trials were included in the analysis. Selected peak hip and knee joint angles and moments were measured during the first 40° of knee flexion across the stance phase.

Results. Females demonstrated significantly less peak hip abduction than did males. Otherwise, there were no gender differences in selected peak hip and knee joint kinematics and moments.

Conclusions. Male and female collegiate soccer players demonstrate similar hip and knee joint mechanics while performing a randomly cued cutting maneuver.

Relevance. Because it is known that females incur a greater number of anterior cruciate ligament injuries than males, it is of interest to identify gender differences in lower extremity mechanics when performing sport specific tasks. Understanding of these differences will contribute to the development of prevention training programs.     

Hip, knee, ankle kinematics and kinetics during stair ascent and descent in healthy young individuals

BACKGROUND: Few studies have reported the biomechanical aspects of stair climbing for this ergonomically demanding task. The purpose of this ethically approved study was to identify normal functional parameters of the lower limb during stair climbing and to compare the actions of stair ascent and descent in young healthy individuals. METHODS: Thirty-three young healthy subjects, (16 M, 17 F, range 18-39 years) participated in the study. The laboratory staircase consisted of four steps (rise height 18 cm, tread length 28.5 cm). Kinematic data were recorded using 3D motion analysis system. Temporal gait cycle data and ground reaction forces were recorded using a force platform. Kinetic data were standardized to body mass and height. FINDINGS: Paired-samples t tests showed significantly greater hip and knee angles (mean difference standard deviation (SD): hip 28.10 degrees (SD 4.08), knee 3.39 degrees (SD 7.20)) and hip and knee moments (hip 0.25 Nm/kg (SD 0.18), knee 0.17 Nm/kg (SD 0.15)) during stair ascent compared to descent. Significantly greater ankle dorsiflexion angles (9.90 degrees (SD 3.80)) and plantarflexion angles (8.78 degrees (SD 4.80)) were found during stair descent compared to ascent. Coefficient of variation (mean (SD)) in percentage between repeated tests varied for joint angles and moments, respectively (2.35% (SD 1.83)-17.53% (SD 13.62)) and (4.65% (SD 2.99)-40.73% (SD 24.77)). INTERPRETATION: Stair ascent was shown to be the more demanding biomechanical task when compared to stair descent for healthy young subjects. The findings from the current study provide baseline measures for pathological studies, theoretical joint modelling, and for mechanical joint simulators.     

The influence of gender on skeletal muscle endurance capacity

Abstract

Skeletal muscle function and its role in providing joint stability has been the focus of considerable interest over the last few years. A proven relationship between spinal pain and sub-optimal muscle function, including endurance capacity, affirms the importance of functional stability re-training in the management of patients with neuromusculoskeletal dysfunction. Clinical protocols, based upon the use of the same target forces, repetitions, and contraction times for both genders are currently used as a basis for evaluating changes in spinal muscle endurance capacity. However these protocols do not account for the gender-related differences in endurance capacity that have been shown to exist in some of the literature, where women have recorded higher values for endurance capacity compared with men. This paper reviews the literature that has sought to evaluate the influence of gender on endurance capacity, discusses the physiological mechanisms that may account for observed differences, and considers the possible clinical implications for physiotherapists.     

Alterations in muscle activation patterns during robotic-assisted walking

OBJECTIVE: The goal of this study was to compare the muscle activation patterns in various major leg muscles during treadmill ambulation with those exhibited during robotic-assisted walking. BACKGROUND: Robotic devices are now being integrated into neurorehabilitation programs with promising results. The influence of these devices on altering naturally occurring muscle activation patterns utilized during walking have not been quantified. METHODS: Muscle activity measured during 60 s of walking was broken up into individual stride cycles, averaged, and normalized. The stride cycle was then broken up into seven distinct phases and the integrated muscle activity during each phase was compared between treadmill and robotic-assisted walking using a multi-factor ANOVA. RESULTS: Significant differences in the spatial and temporal muscle activation patterns were observed across various portions of the gait cycle between treadmill and robotic-assisted walking. Activity in the quadriceps and hamstrings was significantly higher during the swing phase of Lokomat walking than treadmill walking, while activity in the ankle flexor and extensor muscles was reduced throughout most of the gait cycle in the Lokomat. CONCLUSIONS: Walking within a robotic orthosis that limits the degrees of freedom of leg and pelvis movement leads to changes in naturally occurring muscle activation patterns. RELEVANCE: An understanding of how robotic-assisted walking alters muscle activation patterns is necessary clinically in order to establish baseline patterns against which subject's with neurological disorders can be compared. Furthermore, this information will guide further developments in robotic devices targeting gait training.     

Low back three-dimensional joint forces, kinematics, and kinetics during walking

OBJECTIVE: The purpose of this study was to examine the three-dimensional low back loads, spinal motions, and trunk muscular activity during gait. Specific objectives involved assessment of the effects of walking speed, and arm swing on spinal loads, lumbar spine motion, and muscular activation. DESIGN: An in vivo modeling experiment using five male participants. Thirty walking trials were performed by each participant yielding five repeats of each condition (3 walking cadences x 2 arm swing conditions). BACKGROUND: Walking is often prescribed as a rehabilitation task for individuals with low back injuries. However, there are few studies which have examined the joint loading, spinal motions, and muscular activity present when walking. Additionally, the majority of studies examining spine loading during gait have used an inverse dynamics model, commencing at the cranial aspect of the body, approach which does not include the impulsive phases of gait (i.e. heel strikes and toe offs). METHODS: Low back joint forces (bone on bone) and moments were determined using an anatomically complex three-dimensional model (detailing 54 muscles and the passive structures acting at the low back) during three walking cadences and with free arm swing or restricted arm swing. In order to assess the influence of the transient factors such as heel contact on the joint forces a bottom up (from the feet to the lumbar spine) rigid link segment analyses approach was used as one input to the three-dimensional anatomic model. Lumbar spine motion and trunk muscle activation levels were also recorded to assist in partitioning forces amongst the active and passive tissues of the low back. RESULTS: Net joint anterior-posterior shear loading was the only variable significantly affected by walking cadence (fast versus slow P < 0.0003). No variable was significantly affected by the arm swing condition. Trends demonstrated an increase in all variables with increased walking cadence. Similarly, most variables, with the exception of axial twist and lateral bend lumbar spine motion and lateral joint shear, demonstrated increasing trends caused by the restriction of normal arm swing. CONCLUSIONS: Tissue loading during walking appears to be below levels caused by many specific rehabilitation tasks, suggesting that walking is a wise choice for general back exercise and rehabilitation programs. Slow walking with restricted arm swing produced more 'static' lumbar spine loading and motion patterns, which could be detrimental for certain injuries and tissues. Fast walking produced a more cyclic loading pattern.     

Alterations in lower extremity movement and muscle activation patterns in individuals with knee osteoarthritis

OBJECTIVE: The purpose of this study was to investigate lower extremity movement and muscle activation patterns in individuals with knee osteoarthritis and healthy age- and gender-matched control subjects. DESIGN: This study utilized a non-randomized case-control design to compare 24 subjects with unilateral symptomatic knee osteoarthritis to 24 age- and gender-matched control subjects without knee osteoarthritis. BACKGROUND: It is hypothesized that knee osteoarthritis is associated with altered lower extremity movement and muscle activation patterns. METHODS: A gait analysis was performed to determine the lower extremity movement and muscle activation patterns when walking on a level surface at 1.12 to 1.34 m/s and while descending a 20 cm step. Paired t-tests were used to compare the average of five trials between the groups. RESULTS: Subjects with knee osteoarthritis demonstrated less excursion of the knee in the sagittal plane from heelstrike to peak flexion before midstance (i.e. during loading). Subjects with knee osteoarthritis also demonstrated reduced peak vertical ground reaction forces relative to body weight. The muscle activity patterns were also different between the groups. The vastus lateralis, medial hamstrings, tibialis anterior and medial gastrocnemius were on approximately 1.5 times longer than the same muscles in the control subjects. Additionally, significant increases in muscle co-activation were also observed in individuals with knee osteoarthritis during walking. Similar findings were observed when the subject descended a 20 cm step.     

Influence of gravity compensation on kinematics and muscle activation patterns during reach and retrieval in subjects with cervical spinal cord injury: an explorative study

Many interventions in upper-limb rehabilitation after cervical spinal cord injury (CSCI) use arm support (gravity compensation); however, its specific effects on kinematics and muscle activation characteristics in subjects with a CSCI are largely unknown. We conducted a cross-sectional explorative study to study these effects. Nine subjects with a CSCI performed two goal-directed arm movements (maximal reach, reach and retrieval) with and without gravity compensation. Angles at elbow and shoulder joints and muscle activation were measured and compared. Seven subjects reduced elbow extension (range 1.8°-4.5°) during the maximal reaching task with gravity compensation. In the reach and retrieval task with gravity compensation, all subjects decreased elbow extension (range 0.1°-11.0°). Eight subjects executed movement closer to the body. Regarding muscle activation, gravity compensation did not influence timing; however, the amplitude of activation decreased, especially in antigravity muscles, namely mean change +/- standard deviation of descending part of trapezius (18.2% +/- 37.5%), anterior part of deltoid (37.7% +/- 16.7%), posterior part of deltoid (32.0% +/- 13.9%), and long head biceps (49.6% +/- 20.0%). Clinical implications for the use of gravity compensation in rehabilitation (during activities of daily living or exercise therapy) should be further investigated with a larger population.     

Comparison of static and dynamic knee kinematics during squatting

Background

There long has been debate whether static knee kinematics measured using magnetic resonance imaging are the same as knee kinematics in dynamic weight-bearing motion. Magnetic resonance imaging provides excellent volumetric detail but is static. Fluoroscopic imaging provides for dynamic observation of knee kinematics but provides no direct observation of the soft-tissue structures. We attempted to answer the question ‘Are knee kinematics the same during static and dynamic squatting?’

Methods

Knee kinematics data from two previously reported studies of healthy knee kinematics during squatting from 0° to 120° were obtained. The results of the dynamic fluoroscopic study were reformatted to perform a direct comparison of femoral anteroposterior translation and internal–external rotation with the static magnetic resonance imaging study.

Findings

Comparison of internal–external rotations and lateral femoral condyle anteroposterior translations did not reveal significant differences between static and dynamic data. The medial femoral condyle demonstrated 0 (SD = 3) mm posterior translation during dynamic squatting from 0° to 120° flexion compared to 5 (SD = 3) mm posterior translation during static squatting (P = 0.01, Cohen's d = 1.7).

Interpretation

For squatting types of motions, static and dynamic study protocols appear to produce equivalent knee kinematics with no functionally important differences. Differences in medial condyle translations can be attributed to differences in foot position during the study. Investigators can choose the modality that best fits their goals and resources with the knowledge that the results for squatting activities are comparable.     

Effects of supramalleolar osteotomies for ankle osteoarthritis on foot kinematics and lower leg muscle activation during walking

Background

Early stages of asymmetric ankle osteoarthritis can be treated by joint preserving supramalleolar osteotomies that surgically realign the ankle and unload degenerated cartilage. While studies have already shown pain relief and functional improvements, the effects on gait biomechanics are largely unknown. This study investigated patients' gait pattern after supramalleolar osteotomies by focusing on foot kinematics and lower leg muscle activation.

Methods

An instrumented three-dimensional gait analysis with simultaneous electromyography of gastrocnemius medialis and lateralis, soleus, peroneus longus, and tibialis anterior muscles was performed on 12 patients with ankle osteoarthritis, seven of which were followed up 12–18 months postoperatively. Additionally, seven different long-term follow-up patients (8–9 years postoperatively) and 15 healthy control subjects were measured. The waveforms of the foot kinematics and muscle activation were analyzed using principal component analysis.

Findings

Compared to healthy controls, principal component scores that affected the sagittal range of motion of the hindfoot and hallux were lower in all patient groups, while scores that affected the timing of the peaks in the sagittal forefoot motion were mainly altered in short-term follow-up patients. Lower principal component scores in patients with ankle osteoarthritis and short-term follow-up patients resulted in a less pronounced peak activation of gastrocnemius medialis and soleus.

Interpretation

Both postoperative patient groups showed similar adaptations in their gait pattern as those observed in patients with ankle osteoarthritis. These changes are probably related to the lower ankle mobility. However, the reduced mobility seems to affect the patients' well-being less than a painful joint.     

The effect of inturning of the foot on knee kinematics and kinetics in children with treated idiopathic clubfoot

OBJECTIVE: To assess the effect of internal foot progression angle (inturning) on knee dynamics in children with treated clubfeet. DESIGN: Prospective study dividing a population of clubfeet according to the factor inturning. BACKGROUND: Excessive internal or external foot progression angle increases knee flexion by a backward shift of the ground reaction force to the knee joint in children with cerebral palsy. Similarly, inturning in clubfeet was hypothesized to shift the ground reaction force backwards with reference to the knee joint, increasing the external knee flexion moment and the maximal knee flexion at stance. METHODS: Three-dimensional gait analysis was performed on 20 children with surgically treated clubfeet (n=28) to assess alterations of knee dynamics related to inturning (>7 degrees ) and on 13 normal children. RESULTS: Inturning occurred in 46% of the clubfeet and was associated during stance, at maximal knee flexion, to an increase in maximal knee flexion (+7 degrees ), external knee flexion moment (+60%) and related lever arm to the knee (+100%) and at minimal knee flexion, to a reduction in external knee extension moment (-62%) and related lever arm (-58%). Inturning was associated with a more frequent prolongation of internal knee extension moment and of rectus femoris activity exceeding 50% of stance. CONCLUSION: Inturning in clubfeet is associated with knee dynamics alteration, which might contribute to the long-term development of knee osteoarthritis. RELEVANCE: The therapeutic correction of inturning in clubfeet would be of importance if the consecutive knee dynamics alteration is shown by further studies to contribute to long-term degenerative knee pathology.     

基于等速技术的健康成人膝关节屈伸肌肌力的年龄和性别特征的研究

目的:应用等速技术研究200例健康成人膝关节屈伸肌肌力的年龄和性别特征,为膝关节运动功能的康复提供参考依据。方法:将200例健康成人按性别分组,再按年龄分为20—29岁、30—39岁、40—49岁、50—59岁、60—70岁5组,共10组,每组20例。对所有受试者进行膝关节的等速向心肌力测试,采集屈伸肌最大峰力矩值(PT)、屈伸肌相对峰力矩(PT/BW)和屈伸肌峰力矩比值(F/E)指标。利用Pearson相关系数分析各测试指标与年龄的相关性,采用独立样本t检验分析不同性别组内相邻两年龄组之间的差异性。结果:(1)膝关节屈伸肌PT值、PT/BW值及屈伸肌峰力矩比值F/E均与年龄之间具有显著相关性(P<0.01)。(2)男性屈伸肌PT值和PT/BW值40岁以后下降显著(P<0.05);F/E值60岁以后显著增加(P<0.05)。(3)女性屈肌PT值在20—70岁之间呈缓慢下降趋势;屈肌PT/BW值与伸肌PT值60岁以后下降明显(P<0.05);伸肌PT/BW值分别于30岁和60岁以后下降明显(P<0.05);F/E值20—70岁呈平稳增长趋势。(4)同一年龄段...     

The effects of powered ankle-foot orthoses on joint kinematics and muscle activation during walking in individuals with incomplete spinal cord injury

Background  

Powered lower limb orthoses could reduce therapist labor during gait rehabilitation after neurological injury. However, it is not clear how patients respond to powered assistance during stepping. Patients might allow the orthoses to drive the movement pattern and reduce their muscle activation. The goal of this study was to test the effects of robotic assistance in subjects with incomplete spinal cord injury using pneumatically powered ankle-foot orthoses.     

The influence of specific training on trunk muscle recruitment patterns in healthy subjects during stabilization exercises

Low back pain is a major problem involving high medical costs, therefore effective prevention strategies are essential. Stabilization exercises seem to facilitate the neuromuscular control of the lumbar spine and may be useful in prevention programs. To investigate whether specific lumbar stabilization training has an effect on muscle recruitment patterns in a healthy population, in the present study 30 subjects were recruited to perform two types of testing exercises, i.e. bridging exercises and exercises in four-point kneeling, both before and after training. Surface electromyographic data of different abdominal and back muscles were obtained. After training, analysis of the relative muscle activity levels (percentage of maximal voluntary isometric contraction) showed a higher activity of the local (segmental-stabilizing) abdominal muscles, but not of the local back muscles; minimal changes in global (torque-producing) muscle activity also occurred. Analysis of the local/global relative muscle activity ratios revealed higher ratios during all exercises after training, although not all differences were significant. These results indicate that muscle recruitment patterns can be changed in healthy subjects by means of a training program that focuses on neuromuscular control. Additional studies are needed to evaluate this type of training as a prevention strategy.     

The effect of electromagnetic navigation in total knee arthroplasty on knee kinematics during functional activities using flexible electrogoniometry

Background

Navigated total knee arthroplasty has been shown to increase accuracy in post operative implant alignment. By contrast navigated total knee arthroplasty has not shown significant functional improvements to date, when compared with conventional surgery using subjective clinical questionnaire scores. The aim of this study was to compare the knee joint kinematics measured during functional activities using electrogoniometry 12 months after total knee arthroplasty in randomised navigated and conventional total knee arthroplasty groups.

Methods

The study design was a double blinded, randomised, prospective, controlled trial. The patients were randomised into 2 surgical groups (n = 102 navigated group, n = 98 conventional group; mean age navigated = 67, conventional = 67). Flexible electrogoniometry was used to measure patient's knee kinematics with respect to time during 12 functional activities.

Findings

No significant difference was found in terms of the maximum, minimum and excursion knee joint angle during any of the functional activities. However there was a statistically significant improvement in the level and slope gait cycle at the pre swing phase in the navigated group.

Interpretation

There were minimal functional improvements in the navigated total knee arthroplasty group 12 months after surgery. However, these are unlikely to have a significant effect on daily activity for the navigated group.     

Shoulder kinematics and kinetics during two speeds of wheelchair propulsion

The primary objective of this study was to examine the kinematics and kinetics of the shoulder during wheelchair propulsion at a slow and moderate speed. Twenty-seven individuals with paraplegia propelled their wheelchairs at speeds of 0.9 m/s and 1.8 m/s while a motion analysis system captured movements of their upper limbs and SMART(Wheel)s simultaneously recorded their pushrim kinetics. Intraclass R correlation and Cronbach's coefficient alpha statistics revealed that all shoulder parameters were stable and consistent between strokes and speeds. The shoulder exhibited a greater range of motion, and forces and moments at the shoulder were 1.2 to 2.0 times greater (p < 0.05) during the 1.8 m/s speed trial. Peak posterior forces occurred near the end of the propulsion phase, and at the same time, the shoulder was maximally flexed and minimally abducted (p > 0.1). Shoulder positioning and the associated peak shoulder loads during propulsion may be important indicators for identifying manual wheelchair users at risk for developing shoulder pain and injury.     

The immediate effects of foot orthoses on hip and knee kinematics and muscle activity during a functional step-up task in individuals with patellofemoral pain

BackgroundEvidence shows that anti-pronating foot orthoses improve patellofemoral pain, but there is a paucity of evidence concerning mechanisms. We investigated the immediate effects of prefabricated foot orthoses on (i) hip and knee kinematics; (ii) electromyography variables of vastus medialis oblique, vastus lateralis and gluteus medius during a functional step-up task, and (iii) associated clinical measures.MethodsHip muscle activity and kinematics were measured during a step-up task with and without an anti-pronating foot orthoses, in people (n = 20, 9 M, 11 F) with patellofemoral pain. Additionally, we measured knee function, foot posture index, isometric hip abductor and knee extensor strength and weight-bearing ankle dorsiflexion.FindingsReduced hip adduction (0.82°, P = 0.01), knee internal rotation (0.46°, P = 0.03), and decreased gluteus medius peak amplitude (0.9 mV, P = 0.043) were observed after ground contact in the ‘with orthoses’ condition. With the addition of orthoses, a more pronated foot posture correlated with earlier vastus medialis oblique onset (r = − 0.51, P = 0.02) whilst higher Kujala scores correlated with earlier gluteus medius onset (r = 0.52, P = 0.02).InterpretationAlthough small in magnitude, reductions in hip adduction, knee internal rotation and gluteus medius amplitude observed immediately following orthoses application during a task that commonly aggravates symptoms, offer a potential mechanism for their effectiveness in patellofemoral pain management. Given the potential for cumulative effects of weight bearing repetitions completed with a foot orthoses, for example during repeated stair ascent, the differences are likely to be clinically meaningful.     

Gender differences in lower extremity kinematics,kinetics and energy absorption during landing

OBJECTIVE: To determine whether gender differences exist in lower extremity joint motions and energy absorption landing strategies between age and skill matched recreational athletes. DESIGN: Mixed factor, repeated measures design. BACKGROUND: Compared to males, females execute high demand activities in a more erect posture potentially predisposing the anterior cruciate ligament to greater loads and injury. The preferred energy absorption strategy may provide insight for this performance difference. METHODS: Inverse dynamic solutions estimated lower extremity joint kinematics, kinetics and energetic profiles for twelve males and nine females performing a 60 cm drop landing. RESULTS: Females demonstrated a more erect landing posture and utilized greater hip and ankle joint range of motions and maximum joint angular velocities compared to males. Females also exhibited greater energy absorption and peak powers from the knee extensors and ankle plantar-flexors compared to the males. Examinations of the energy absorption contributions revealed that the knee was the primary shock absorber for both genders, whereas the ankle plantar-flexors muscles was the second largest contributor to energy absorption for the females and the hip extensors muscles for the males. CONCLUSIONS: Females may choose to land in a more erect posture to maximize the energy absorption from the joints most proximal to ground contact. RELEVANCE: Females may be at a greater risk to anterior cruciate ligament injury during landing due to their energy absorption strategy.