Semester

Summer

Date of Graduation

2025

Document Type

Thesis (Campus Access)

Degree Type

MS

College

School of Medicine

Department

Exercise Physiology

Committee Chair

Jean McCrory

Committee Member

Justin Payette

Committee Member

Corrie Mancinelli

Abstract

Introduction: ACL Return to Sport Assessments include tests of single-legged function. These tests may overestimate rehabilitation status. The purpose of this study was to determine if a double-legged double hop will reveal quantitative biomechanical asymmetries that may be present at the time of return to sport in athletes following ACL reconstruction. Specific Aims: Specific Aims 1 and 2 compared hip and knee extension moments between limbs and groups during a double leg double hop. Specific Aim 3 compared the relative joint work contributions of the hip, knee, and ankle between limbs and groups during the double leg double hop Methods: Twenty-one individuals who have undergone a unilateral ACL reconstruction (8 females, 13 males; age = 19.04±3.47 years; height = 68.52±4.11 in; weight = 163.52±27.51 lbs) and twenty-one sex and activity level matched controls (8 females, 13 males; age = 22.85±2.97; height = 69.23±3.88 in; weight = 162.48±26.90 lbs) participated in this study. This study assessed the three-dimensional kinematics and kinetics of the hip, knee, and ankle joints during a dynamic double-legged double-hop task using force plates and a motion capture system. Reflective markers were placed on lower extremity segments, as well as the pelvis and spine. Following anatomical calibration, participants performed the task until at least three good trials were obtained. Five kinetic variables pertaining to the Specific Aims of this study were calculated, including hip extension moments, hip limb symmetry, knee extension moments, knee limb symmetry, and joint work contribution. Statistical analyses were performed using the SPSS statistical software. Two-factor ANOVAs (group, limb) were performed for both hip and knee extension moments. Two one-factor ANOVAs (group) were performed with limb symmetry index with the hip and knee extensor moments as the outcome variable. A three-factor ANOVA (group, limb, joint) was performed to compare the relative joint work contributions of the hip, knee, and ankle. Seven kinetic variables outside of the Specific Aims of this study were also calculated in Excel to provide context for interpreting the results. Results: Statistically significant differences were found for all variables pertaining to the Specific Aims, except the joint work contribution. Statistically significant differences were also present in five of the variables collected outside of the Specific Aims. Conclusion: This study aimed to examine the three-dimensional kinetics of the hip, knee, and ankle joints during a dynamic double legged double hop task in individuals who have undergone ACL reconstruction and healthy controls. Statistical significance was found for the following variables: hip extension moments, hip limb symmetry, knee extension moments, knee limb symmetry, joint work, combined extensor moment at landing, combined extensor moment at take-off, peak knee angles, peak ankle angles, and ankle limb symmetry. These findings highlight the complexity of movement patterns in dynamic bilateral tasks in individuals who have undergone ACL reconstruction and suggest that the current return to play testing battery may overestimate or underestimate the functional capacity of the lower limb during the rehabilitation process.

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