The effect of cognitive loading on the lower extremity movement coordination variability in patients with anterior...

The altered coordination variability was related to anterior cruciate ligament (ACL) re-injury after ACL reconstruction (ACL-R). As motor performance is affected by the cognitive loading, understanding the interaction of cognition and coordination variability is crucial for addressing secondary injury prevention and restoring function in rehabilitation programs.

To investigate the lower extremity movement coordination variability asymmetry in individuals following ACL-R and determine the effects of cognitive loading on the coordination variability.

Twenty-five males who received unilateral ACL-R using hamstring tendon autograft (7.4 ± 1.3 months past reconstruction). Participants performed walking without (single-task condition) and with the concurrent cognitive task (dual-task condition). The coordination variability in hip-knee coupled motion in different gait phases was calculated using vector coding technique.

The injured leg demonstrated greater coordination variability in hip flexion/knee flexion (HF/KF) during mid-stance phase (P = 0.012) than the uninjured leg in both conditions. No significant differences were observed in other phases of HF/KF variability or other measures in all phases between the injured and uninjured legs. Both legs increased the HF/KF coordination variability during loading response phase in dual-task condition than that in single-task condition (P < 0.001).

Individuals following ACL-R demonstrated coordination variability asymmetry of sagittal plane hip-knee coupled motion. The dual cognitive task increased the coordination variability of hip flexion/knee flexion during loading response phase in individuals following ACL-R.