Influence of Running Speed and Time Post-Operatively on Lower Extremity Work in Collegiate Athletes after Anterior Cruciate Ligament Reconstruction.

Abstract

Purpose: Following anterior cruciate ligament reconstruction (ACLR), individuals present with significant and persistent deficits in surgical knee biomechanics during running. Little is known regarding the role of the hip and ankle in compensating for these knee-specific deficits. The purpose of this study was to characterize how limb (surgical and non-surgical), time post-operatively (3.5-7 months [EARLY], 8-13 months [LATE]), and running speed influence lower extremity joint-specific and total work during running post-ACLR.

Methods: Fifty-six Division I collegiate athletes post-ACLR (EARLY: n = 41, LATE: n = 42, Both: n = 27) completed running analyses at 2.68, 2.95, 3.35, 3.80 and 4.47 m/s or up to their maximum comfortable speed. Linear mixed effects models assessed the influence of limb, speed, time post-ACLR, and their interactions on hip, knee, ankle, and total negative and positive work.

Results: Surgical limb hip positive work was greater (0.044 J/kg [0.015, 0.074], p < 0.001) than the non-surgical limb EARLY. Surgical limb ankle negative (-0.054 J/kg [-0.093, -0.015], p = 0.003) and positive work (-0.115 J/kg [-0.168, -0.063], p < 0.001) were less than the non-surgical limb EARLY. Surgical limb knee negative (EARLY: -0.339 J/kg [-0.382, -0.296], p < 0.001; LATE: -0.222 J/kg [-0.265, -0.180], p < 0.001) and positive work (EARLY: -0.214 J/kg [-0.246, -0.182], p < 0.001; LATE: -0.142 J/kg [-0.174, -0.110], p < 0.001) were less than the non-surgical limb. Total negative and positive work followed the same pattern as the knee. Conclusions: Athletes post-ACLR exhibited greater hip positive work and lesser ankle positive and negative work during running of the surgical limb EARLY, that resolved LATE. Both knee and total negative and positive work of the surgical limb were substantially less than the non-surgical limb, which improved from EARLY to LATE, but between-limb asymmetries remained.