Lower Limb Asymmetry Research Articles

Differential diagnosis of pathologically induced upper and lower limb asymmetry in a burial from late medieval Ireland (CE 1439–1511)

This paper reports a case study from 15 to 16th century Ireland of a mature adult male with upper and lower limb asymmetry. All of the bones of the right upper and lower extremity were atrophied and demonstrated limb shortening. This individual also had severe scoliosis and accessory facets on the superior aspect of the distal ends of the right metatarsals. These facets were most likely caused by the individual walking predominately on his toes to make up for the height difference between the lower limbs. Based on the patterning of affected bones and associated pathological changes, the individual was diagnosed as suffering from cerebral palsy with right-sided hemiplegia. Few definite cases of cerebral palsy have been identified in the archaeological record and most often only include the shortening of one or two long bones. The case from Ballinderry provides one of the most definitive archaeological cases to date.

Scoliosis: lower limb asymmetries during the gait cycle.

BackgroundSeveral studies indicate that the gait pattern of subjects suffering from scoliosis differs from the norm. However, there is conflicting evidence regarding the source of this discrepancy.ObjectiveTo evaluate lower limb asymmetries in selected gait variables.Study designA case–control study on lower limb asymmetries during gait which can be related to scoliosis.Methods31 subjects with scoliosis (Study Group - SG) and an equal comparative control sample (Control Group – CG) of subjects underwent objective gait analysis with the Vicon® motion caption system whilst walking at a comfortable speed along the gait laboratory walkway. Analysis was performed at three levels: (1) Asymmetry in the SG against asymmetry in the CG, (2) Difference in magnitude of asymmetry between the SG and CG, and (3) Global mean values in the SG vs. CG. The Paired Student T-Test was used for intra-group analysis whilst the Independent Student T-Test was used for inter-group analysis of the selected parameters, which include temporal parameters (stride length, stride time, step length, individual step speed, speed of gait, cadence, swing-to-stance ratio), ground reaction force (peak GRF values during Loading and Propulsion phases, vertical component only) and electromyography (peak EMG values and their time of onset, as a percentage of the gait cycle) of two lower limb muscles (Gastronemius and Vastus Medialis).ResultsNo intra-group variation was found to be significant. However, the speed of gait was found to be significantly slower (p = 0.03) in scoliotic subjects when compared to the norm, as a result of the shorter stride length (p = 0.002 and longer stride time (p = 0.001) in the SG. Furthermore, there was statistical significance in the time of onset of EMG peaks for the Lateral Gastrocnemius (p = 0.02) with regards to inter-group difference in magnitude of lower limb asymmetry and global mean values.ConclusionsScoliosis is a tri-planar deformity which has some impact on the gait pattern. This research study concludes that scoliotic subjects have a slower speed of gait due to a shorter stride length and a longer stride time, together with variations in the timing of muscle activation.

Quality of functional movement patterns and injury examination in elite-level male professional football players.

The purpose of this study is to examine the quality of functional movement patterns among one of Hungary's first league soccer clubs, where the elite male football players (N = 20) utilize the well-established Functional Movement Screen™ (FMS) system; a comprehensive functional program designed to determine and identify the quality of movement and the greatest risk factors for non-contact injuries. Furthermore, an additional purpose of this program is to examine injuries over the course of 6 competitive months. Focusing on the mechanisms of injuries and their causes in the lower extremities during this period is one of the key objectives. Over the course of 6 months we found significant differences between ankle injuries and the FMS Hurdle Step exercise (p < 0.05), and the FMS Deep Squat exercise and knee and hip injuries (p < 0.05). The FMS pre-screening system found lower limb asymmetry present in 40% of the participants. The authors believe that the importance of preventative measures and structural sport specific pre-screening cannot be overemphasized, and that there is a growing need for further transparent research in this field in order to be more effective with regard to programs dedicated to injury prevention and the enhancement players' physical performance.

A Six-Week Neuromuscular and Performance Training Program Improves Speed, Agility, Dynamic Balance, and Core Endurance in Junior Tennis Players

A Six-Week Neuromuscular and Performance Training Program Improves Speed, Agility, Dynamic Balance, and Core Endurance in Junior Tennis Players Tennis requires speed, agility, and explosive power. Few studies have assessed the effects of a training program in junior players who are not on an elite or national level. We evaluated the impact of a program that combined components of a knee ligament injury prevention program with other exercises to improve athletic performance indicators. We hypothesized that this program would significantly improve dynamic single-leg balance and function, correct lower limb asymmetry, enhance speed and agility, and improve core endurance.

Strength asymmetry of the knee extensors and physical activity in middle-aged women

Background: Differences between muscle strength and power of lower limbs is one of the factors associated with falls in the elderly population. Muscle strength asymmetry of lower limbs increases with age. Objective: The aim of the study is to assess differences in the volume and intensity of physical activity (PA) in the subgroups of women being at higher and lower risk of falls (with and without strength asymmetry of the knee extensors of dominant and non-dominant lower limb). Methods: Data from 42 women (age 56.3&#x202F;&plusmn;&#x202F;4.4 years; weight 76.5&#x202F;&plusmn;&#x202F;16.1&#x202F;kg; body height 164.3&#x202F;&plusmn;&#x202F;5.2&#x202F;cm; body mass index 28.1&#x202F;&plusmn;&#x202F;5.3&#x202F;kg . m-2) were used for the purpose of the presented analysis. Furthermore the sample was divided into subgroups with lower and higher strength asymmetry of quadriceps muscle (as a criterion the asymmetry greater than 15% was chosen). Absolute concentric peak torque of the knee extensors was evaluated by an isokinetic dynamometer IsoMed 2000 in a sitting position at angular velocity of 180° . s-1. PA was monitored using Yamax SW-700 pedometers throughout 7 consecutive days and using the Czech version of standardized International Physical Activity Questionnaire. Results: Statistically significant differences between groups with lower and higher strength asymmetry were found in the amount of self-reported vigorous PA (p =&#x202F;.04; d =&#x202F;0.6) only. Differences between the observed groups were not significant in self-reported moderate PA and walking. There were also no significant differences in the daily numbers of steps measured objectively. Conclusions: The results of the study indicate that from the point of view of strength asymmetry of knee extensors as a factor associated with falls in middle-aged women, intensity of PA could be an important characteristic of PA. This suggestion should be taken into account in habitual PA and training programs in middle-aged population.

Assessment of Bilateral Asymmetry in Cycling Using a Commercial Instrumented Crank System and Instrumented Pedals

The accuracy of commercial instrumented crank systems for symmetry assessment in cycling has not been fully explored. Therefore, the authors' aims were to compare peak crank torque between a commercial instrumented crank system and instrumented pedals and to assess the effect of power output on bilateral asymmetries during cycling. Ten competitive cyclists performed an incremental cycling test to exhaustion. Forces and pedal angles were recorded using right and left instrumented pedals synchronized with crank-torque measurements using an instrumented crank system. Differences in right (dominant) and left (nondominant) peak torque and asymmetry index were assessed using effect sizes. In the 100- to 250-W power-output range, the instrumented pedal system recorded larger peak torque (dominant 55-122%, nondominant 23-99%) than the instrumented crank system. There was an increase in differences between dominant and nondominant crank torque as power output increased using the instrumented crank system (7% to 33%) and the instrumented pedals (9% to 66%). Lower-limb asymmetries in peak torque increased at higher power-output levels in favor of the dominant leg. Limitations in design of the instrumented crank system may preclude the use of this system to assess peak crank-torque symmetry.

Newborn With Unilateral Lower Extremity Vascular Malformation and Limb Asymmetry

A newborn presents with a unilateral lower-extremity vascular malformation and limb asymmetry. (Figure 1) Figure 1. ### Prenatal and Birth Histories ### Presentation The infant was transferred to the neonatal intensive care unit for issues related to prematurity. His admission physical examination was notable for a large, non-blanching, erythematous patch over the right lower extremity associated with lower limb asymmetry, with right greater than left. ### Vital Signs ### Physical Examination

Incidence of pulmonary embolism during COPD exacerbation

OBJECTIVE:Because pulmonary embolism (PE) and COPD exacerbation have similar presentations and symptoms, PE can be overlooked in COPD patients. Our objective was to determine the prevalence of PE during COPD exacerbation and to describe the clinical aspects in COPD patients diagnosed with PE.METHODS:This was a prospective study conducted at a university hospital in the city of Ankara, Turkey. We included all COPD patients who were hospitalized due to acute exacerbation of COPD between May of 2011 and May of 2013. All patients underwent clinical risk assessment, arterial blood gas analysis, chest CT angiography, and Doppler ultrasonography of the lower extremities. In addition, we measured D-dimer levels and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels.RESULTS:We included 172 patients with COPD. The prevalence of PE was 29.1%. The patients with pleuritic chest pain, lower limb asymmetry, and high NT-pro-BNP levels were more likely to develop PE, as were those who were obese or immobile. Obesity and lower limb asymmetry were independent predictors of PE during COPD exacerbation (OR = 4.97; 95% CI, 1.775-13.931 and OR = 2.329; 95% CI, 1.127-7.105, respectively).CONCLUSIONS:The prevalence of PE in patients with COPD exacerbation was higher than expected. The association between PE and COPD exacerbation should be considered, especially in patients who are immobile or obese.

The effects of strength training on isometric force production symmetry in recreationally trained males

Objectives: The purpose of this investigation was to determine what effect a bilateral strength training regimen has on isometric force production symmetry and if changes in force production symmetry can be accounted for by differences in pre-intervention strength levels. Design: Sixteen recreationally trained males (1-RM squat: 146.8 ± 23.0 kg.) were assigned to two groups for the 7-week training intervention: strong (S) and weak (W) based on pre-training squat isometric peak force allometrically scaled (IPFa) at 120° knee angle. Methods: Subjects completed a 7-week training intervention following a block-periodized model and were tested on mea sures of dynamic (1RM squat) and isometric (isometric squat at 90° and 120° knee angle) strength pre- and post-intervention. The degree of bilateral lower limb asymmetry was calculated as a percentage where 0% symmetry index (SI) indicates perfect symmetry on the isometric squat. Results: ANCOVA results showed no statistical difference between groups for all dependent variables when pre-intervention IPFa 120° scores were used as the covariate. Paired t-tests results showed both groups statistically improved 1RM squat and IPFa 120° (p < 0.05). IPFa 120° SI decreased statistically from pre-training in the W group (p = 0.03). Independent t-test results showed the W group had statistically larger pre-intervention SI scores for IPFa 90° (p = 0.045) and IPFa 120° (p = 0.007); however this difference was no longer present following strength training. There was a strong inverse relationship between pooled IPFa 120° and IPFa 120° SI (r = -0.64, p = 0.004). Conclusions: The findings of the current study support the notion that weaker individuals can augment lower limb symme try with strength training. The same does not seem to be true for stronger individuals who already have a low symmetry index score. These findings indicate that strength training improves force production symmetry in relatively weak males, which may be important for bilateral tasks and injury potential reduction.

Evaluating lower-limb asymmetry in acl-patients: assesment of jumping performance and mechanical muscle function

Introduction: The ratio between the operated and nonoperated leg is typically used to distinguish between normal or abnormal test scores in knee patients (1). Traditionally, the asymmetry ratios are investigated by use of functional tests (i.e. one-leg jump for distance). However, mechanistic outcomes such as kinematic/kinetic data and isolated muscle force/power output may provide further insight into the origin of between-limb asymmetry. The study aim was to investigate differences in asymmetry ratios of unilateral jumpperformance bymeans of kinetic and kinematic analysis andmechanicalmuscle function in ACL-patients and healthy controls. Patients/materials and methods: This case-control study was performed in 23 ACL-reconstructed men (mean age: 27.2 ± 7.5 years and BMI: 25.4 ± 3.2) 18-30 month post-surgery and 25 healthy matched controls (mean age: 27.2 ± 5.4 years and BMI: 24.1 ± 1.8). Patients and controls performed (i) bilateral maximal counter movement jumps (CMJ) with each leg positioned on a separate force plate and (ii) maximal single-leg CMJs. Kinematic data were synchronously recorded by a 6 cameraViconMX system. Subsequently, center of mass jump height (JH), unilateral knee joint range of motion (ROM), unilateral peak (Mpeak) and mean sagittal knee moment (Mmean) were analyzed for the concentric phase, (iii) one-leg maximal jump for distance was performed [1], and (iv)maximal unilateral isometric knee extensor and flexor strength (MVC)weremeasuredusing stabilizeddynamometry [2]. Asymmetry ratios were calculated as operated/non-operated leg for ACLpatients, and non-dominant/dominant leg for controls. Good-tomoderate test-retest reliability has been reported for all measured variables [3]. Differences in asymmetry ratios were evaluated by student’s t-tests using a 0.05 level of significance. Results: No differences in age or BMI were observed between groups. CMJ:Asymmetry ratios for knee jointROMdiffered (p<0.01) between patients and controls in both types of CMJ (96.1% vs. 102.6% and 87.0% vs. 99.9% in bilateral and single-leg CMJs, respectively). Jump for distance: Patients demonstrated greater (p<0.01) asymmetry for jump length (92.9% vs. 98.6%). MVC: Asymmetry in hamstring MVC was greater (p<0.001) for patients than controls (77.4% vs. 101.3%). Discussion & conclusions: ACL patients showed reduced function of the operated leg 18-30 month post ACL-reconstruction for knee ROM, singleleg jump for distance and hamstring MVC. The most prominent reduction was observed for maximal hamstring muscle strength. This finding has significant clinical implications since the hamstring muscles are important protagonists to the ACL [4,5], with reduced hamstring MVC thus representing a potential risk factor for secondary ACL-rupture.

Lower extremity strength and power asymmetry assessment in healthy and mobility-limited populations: reliability and association with physical functioning.

This study assessed the reliability of evaluating asymmetrical strength and power deficits in the lower limbs of healthy middle-aged, healthy older and mobility-limited elders. We also explored the relationship between limb asymmetry and physical functioning. We evaluated baseline knee extension strength and power asymmetry data from a cohort of older adults (n=57; 74.2±0.9 yrs, 26 male) who participated in a lower body strength training study (TS) and from a cross-sectional study of community dwelling volunteers. Cross-sectional participants were recruited into: healthy middle-aged (MH) (n=31; 47.4±4.8 yrs, 14 male), healthy older (OH) (n=28; 74.0±3.6 yrs, 16 male) and mobility-limited older (OML) (n=34; 77.8±4.5 yrs, 16 male) groups. Knee extensor strength (1RM) and power asymmetry at 40% and 70% of 1RM were evaluated for test-retest reliability using intraclass correlation coefficients (ICCs). Knee extension 1RM, and peak power at 40% and 70% asymmetry ICCs exhibited excellent to good reliability in the TS and OML groups (TS= 0.8, 0.7 and 0.7, respectively; OML= 0.7, 0.7, and 0.9, respectively) but not in the MH and OH groups. No consistent association between lower limb asymmetry and measures of physical functioning was observed. Assessment of lower limb strength and power asymmetry is more reliable in mobility-limited elders when compared to healthy middle-aged and older subjects. The relationship of lower limb asymmetry to physical functioning is poor, in contrast to associations between the absolute strength and power of the individual limbs and physical functioning.

Preoperative Ambulatory Measurement of Asymmetric Leg Loading During Sit-to-Stand in Hip Arthroplasty Patients

Total hip arthroplasty (TGA) is a successful surgical procedure to treat patients with hip osteoarthritis. Clinicians use different questionnaires to evaluate these patients. Gait velocity and these questionnaires; usually show significant improvement after TGA . This clinical evaluation does, however, not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which is clinically important and can currently only be obtained in a gait laboratory. There is a need to improve patient instructions and to quantify the rehabilitation process. The sit-to-stand (STS) movement is an objective performance-based task, whose assessment is related with the evaluation of functional recovery. Twenty two patients with hip osteoarthritis participated in this study. For each patient, validated questionnaires were administered and gait velocity was measured. Time, ground reaction forces, and lower limb asymmetry parameters were calculated using the instrumented force shoes (IFS) during STS movement with and without armrest. Significant inter-limb asymmetry was observed. No correlation was found between any parameter and gait velocity and questionnaires outcomes. Significant differences in time and force parameters between with/without armrest were found. Concluding, inter-limb asymmetry can be evaluated with the IFS supplying important additional information not represented by gait velocity and questionnaires usually used.

Analysis of Lower Limb Asymmetries by Isokinetic and Vertical Jump Tests in Soccer Players

Assessment of lower extremity bilateral asymmetries in soccer players is important for both injury prevention and performance. The purpose of this investigation was to compare isokinetic knee extensor assessment of asymmetry with a more specific countermovement jump (CMJ). Forty-six Brazilian male professional soccer players participated in this study. The maximal power, maximal force and impulse were determined during CMJ and the total work and peak torque at 60, 180, and 300°·s during isokinetic leg extension, separately for each leg. Factor analysis was performed for all investigated variables, and the diagnostic concordance between different criteria was analyzed by McNemar's χ test. The factor analysis showed that the isokinetic and CMJ tests were widely independent methods for the assessment of bilateral differences. Concordance of the diagnostic information could only be found between the maximal force during CMJ and the total work and peak torque at 180 and 300°·s during isokinetic leg extension. Impulse and maximal power during CMJ on a double force platform appear to be appropriate additional variables for the identification of bilateral differences. Therefore, it might be pertinent to perform, in addition to isokinetic assessment, a vertical jump test on a force platform to assure widespread and reliable diagnostic information.

Asimetría de extremidades inferiores: Evaluación por imágenes en la edad pediátrica

Limb length discrepancy or anisomelia has long been objectified with imaging.The biomechanical impli - cations for patients with a developing skeleton are more relevant than the cosmetic aspects, both in treatment and in follow-up. The aim of this publication is to review the most common causes of lower limb asymmetry in children, with emphasis on imaging findings, which are of great importance for clinical management. A retrospective review was performed on patients younger than 15 years, who required evaluation at our center for lower limb asymmetry, using simple X-ray, CT scan and /or MRI. The anatomical findings and morphometric analysis were recorded for each case. The causes of limb length discrepancy are many, including congenital and sequelae conditions. A knowledge and proper assessment of the imaging findings helps to improve and standardize the radiology report.

Asymmetry measurement for vibroactive correction in lower limbs mobility

We developed a wearable device to improve lower limb sport training. The presented system consists of a pair of spandex shorts which embed a processor unit, 2 accelerometers and 2 vibro motors. The accelerometers are located in proximity to the knees and measure tri-axial accelerations. We present a novel method to compute and correct asymmetry of lower limbs during training. The user performs an initial calibration phase which sets the accelerometer reference frames. While running, the system continuously refines the calibration using principal component analysis to take in account occasional shorts assessments. The system activates a corrective vibro feedback on the specific leg according to an asymmetry metric based on: (i) foot ground impact, (ii) phase error between legs, (iii) transversal knee movements. User tests demonstrated that the device is ergonomic to wear, easy to use and the corrective vibro feedback is appreciated during the training.

Arm movements during split-belt walking reveal predominant patterns of interlimb coupling

The present study examined upper and lower limb coordination during lower limb asymmetry in a split-belt walking paradigm. Eleven healthy individuals walked on a split-belt treadmill with 4 different speed ratios (2:2, 2:4, 2:6 and 2:8km/h) and the left belt fixed at 2km/h. Spatial (upper and lower limb movement amplitudes) and temporal (correlations between trajectories) aspects of limb movement were analyzed. Results showed that while amplitudes of the right lower limb increased and left lower limb decreased with increasing asymmetry, both upper limb amplitudes increased. Correlations between diagonal upper/lower limb trajectories increased as right belt speed became faster, suggesting increasing cross-body matching regardless of side. As the treadmill asymmetry increased, ipsilateral lower/upper limbs became more out of phase suggesting a more precise gait pattern to regulate timing between limbs. The upper limbs reached maximum horizontal displacement before the lower limbs except between the right upper limb/left lower limb for asymmetrical belt speeds. From these results, it appears the faster moving lower limb drives the motion of both upper limbs. These changes are most likely due to neural mechanisms in which upper and lower limb CPGs regulate full body movement and maintain the rhythmic locomotor pattern.

Kinematic Asymmetries of the Lower Limbs during Ergometer Rowing

Rowing injuries, particularly of the lumbar spine, are often attributed to poor technique. Rowing technique comprises a series of coordinated movements between the back, upper limbs, and lower limbs, and abnormalities in these may lead to injury. The aim of this study was to test the hypothesis that ergometer rowing is symmetrical with respect to lower limb motion and that deviations from symmetry result from rowing experience, work rate, or stroke position. Twenty-two rowers in three levels of ability participated in this study. A motion analysis system was used with an instrumented rowing ergometer, which incorporated load cells at the handle and seat. Kinematic measurements of the knees, hips, lumbar-pelvic joints, and pelvic twist, in addition to measures of handle force, seat force, stroke length, mediolateral seat drift, and mean external power, were made during an incremental step test. Elite rowers exhibited the largest handle force and mean external power (P < 0.01) and least mediolateral seat drift (P < 0.01). All groups demonstrated lower limb asymmetries, with hip asymmetries significantly greater than knee asymmetries (P < 0.01). Regression analysis indicated that both hip and knee range of motion (ROM) asymmetry was significant (P < 0.05) in predicting lumbar-pelvic flexion at the catch and maximum handle force of the stroke. However, hip ROM asymmetry showed a better relation with lumbar-pelvic flexion compared with knee ROM asymmetry, explaining a greater proportion of the variance. Bilateral asymmetries during the rowing stroke, particularly at the hips, can contribute to suboptimal kinematics of the lumbar-pelvic region. Quantification of hip ROM asymmetries may therefore be a useful tool in predicting the development of low back pain in rowers.

Localized hypertrophic neuropathy of the sciatic nerve in children: MRI findings

Localized hypertrophic neuropathy (LHN) of the sciatic nerve in children is a rare condition characterized by a painless neurological deficit in the sciatic nerve territory. To demonstrate the role of MRI using a specific protocol and describe the primary findings in LHN. Imaging in four children (age 2 years to 12 years) is presented. All children presented with lower limb asymmetry. Three had a steppage gait. LHN was confirmed by electrophysiological studies and by MRI of the whole sciatic nerve with a dedicated protocol covering the lumbar spine and the lower limb. There were four direct MRI findings: (1) linear and focal hypertrophy with progressive enlargement of a peripheral nerve or plexus diameter, (2) abnormal hyperintensity of the nerve on T2-weighted images, (3) preserved fascicular configuration, and (4) variable enhancement after intravenous gadolinium administration. In addition there were atrophy and fatty infiltration of innervated muscles. MRI was helpful for determining the extent of lesions and in excluding peripheral nerve compression or tumour. MRI of the whole sciatic nerve is the method of choice for diagnosing LHN of the sciatic nerve.

The functional evaluation of lower limb symmetry in a group of young elite judo and wrestling athletes

Introduction: This project proposes the inclusion of functional assessment as an essential branch of a training program applied to a group of young elite judo and wrestling athletes to investigate for possible asymmetries of lower limbs, a potential cause for future injuries. Methods: AgroupofyoungmaleeliteSardinianjudoandwrestlingathleteswasrandomlyselectedandwerefunctionallyevaluated with three different tests. Strength and balance abilities were measured while muscle power was assessed by measuring jump height, flight time and maximum contraction speed. Subjects were compared according to their right and left leg performance. Results: Generally, no significant bilateral difference were indicated for any of the applied tests, between right and left legs in all considered parameters concerning the three utilized tests, with the exception of peak torque values of the knee extensors. Conclusion: This study indicates that judokas are distinguished by general bilateral symmetry in certain functions. This should serve as an important guideline for both clinicians and coaches.

Effects of Sex on Compensatory Landing Strategies Upon Return to Sport After Anterior Cruciate Ligament Reconstruction

Controlled laboratory, cross-sectional, cohort design. To determine if a sex-specific pattern of lower limb asymmetries is present during a drop vertical jump (DVJ) maneuver at the time of return to sport after anterior cruciate ligament (ACL) reconstruction. A high incidence of second ACL injury is reported after reconstruction; however, the underlying mechanisms of this injury are unclear. While asymmetrical dynamic loading patterns predictive of primary ACL injury in healthy female athletes were observed in female athletes 2 years after ACL reconstruction, it is unknown if similar asymmetries are present in male athletes after ACL reconstruction at the time of return to sport. A total of 98 participants were included in the study, 56 of whom had unilateral ACL reconstruction (35 female, 21 male) and had been released to return to unrestricted level 1 and 2 sports, and 42 of whom were uninjured, activity-matched control participants (29 female, 13 male). Lower extremity kinetic data were analyzed during a bilateral drop vertical jump maneuver from a 31-cm box. Peak vertical ground reaction force (VGRF) was calculated during the landing phase of the drop vertical jump and normalized to body weight (BW). A 2-by-2-by-2 analysis of variance was used to determine differences between side (involved versus uninvolved), group (ACL reconstruction versus control), and sex (female versus male) for the peak VGRF. A significant side-by-group interaction for peak VGRF (P = .002) was observed during the landing phase of the drop vertical jump in the entire cohort. The involved limb of the ACL reconstructed group displayed significantly lower VGRF (mean ± SD, 1.77 ± 0.35 BW) than the uninvolved limb (2.2 ± 0.4 BW, P<.001) and both the preferred limb (2.0 ± 0.4 BW, P = .002) and nonpreferred limb (2.09 ± 0.42 BW, P<.001) in the control group. No effect of sex was noted. After ACL reconstruction, both male and female participants at the time of return to sport demonstrated involved limb asymmetries in peak VGRF during landing from a bipedal task. These deficits, which persist at the time of return to sport, may increase the risk of future injury and indicate that rehabilitation after ACL reconstruction may require more targeted interventions to address involved limb biomechanical deficits in athletes of both sexes prior to return to sport participation.