Improvements in landing biomechanics following anterior cruciate ligament reconstruction in adolescent athletes

ABSTRACT

Motion analysis offers objective insight into biomechanics, rehabilitation progress and return to sport readiness. This study examined changes in three-dimensional movement patterns during drop jump landing between early and late stages of rehabilitation in adolescent athletes following anterior cruciate ligament reconstruction (ACLR). Twenty-four athletes (58% female; mean age 15.4 years, SD 1.2) with unilateral ACLR underwent motion analysis testing 3–6 months and again 6–10 months post-operatively. Kinematics and kinetics were compared between visits and between limbs using repeated measures ANOVA. The operative side exhibited lower vertical ground reaction force, less energy absorption and lower sagittal external moments at the knee and ankle, and lower peak dorsiflexion angles compared with the non-operative side regardless of visit. Between visits, hip and knee flexion increased bilaterally, as well as hip flexion moments and energy absorption. During early rehabilitation following ACLR, adolescent athletes reduced flexion and loading of the knee and ankle on their operative limb. Motion and loading increased over time, particularly at the hip, but remained reduced at the knee and ankle 6–10 months post-operatively.

KEYWORDS:

• Motion analysis
• vertical drop jump
• return to sport
• ACL injury

Acknowledgements

The authors would like to thank our Sports Motion Lab team—Bitte Healy, Henry Lopez and Kyle Chadwick for their help with data collection and data processing.

Disclosure statement

One author is a consultant for Arthex and Ceterix, and another receives general research support from Neural Analytics; no company was involved in any aspect of this study. The remaining authors have no conflicts of interest to declare.