Hip, knee, and ankle running kinematics during stance for anterior cruciate ligament reconstruction patients

While functional data analysis facilitates extensive interpretation of movement patterns, there are limited studies utilizing functional data analysis to examine running biomechanics in individuals post-ACLR. The current study aimed to determine altered running biomechanics in individuals with unilateral ACLR compared to the contralateral limb and matched control limbs.

Twenty ACLR patients (time post-ACLR: 14.6 ± 6.1 months) and 20 matched controls participated in the study. All participants ran for 30 min at a self-selected speed (minimum 2.68 m/s) on an instrumented tandem treadmill. Frontal and sagittal lower extremity kinematics were calculated, and functional analysis of variance was used to compare the ACLR and contralateral limbs and the ACLR and control limbs.

Relative to the control limbs, the ACLR limbs showed decreased knee flexion and ankle dorsiflexion angles from initial contact to approximately 90% of stance phase. Compared to the contralateral limbs, the ACLR limbs also demonstrated decreased 1.7° knee flexion and 1.2° ankle dorsiflexion angle in the mid-stance phase during running.

Compared with the contralateral limbs and control limbs, the ACLR limbs demonstrated reduced joint excursions with decreased knee and hip flexion angles and ankle dorsiflexion angle. Future work may seek to determine whether these changes during running are associated with OA-related joint tissue changes.