2017 Volume 12 Issue 2 Pages 16-00694
Anterior cruciate ligament reconstruction (ACL-R) surgery can improve knee joint stability; however, altered sensory feedback after reconstruction surgery might affect the movement control which is required by proper multijoint coordination to compensate for the impaired sensorimotor function. The purpose of this study was to determine how interjoint coordination changed during stair walking in individuals with ACL-R compared with the control group and how interjoint coordination was affected by the stair height. Sixteen individuals with unilateral ACL-R and 16 healthy age- and sex-matched controls were recruited. Participants were instructed to ascend and descend a 4-step stairs with two different heights at their self-selected speed. Kinematic data were collected during stair walking using a motion analysis system. Interjoint coordination and muscle strength of the lower extremities were investigated. The root-mean-squared difference, cross-correlation coefficient, and deviation phase of the relative phase angles were used to quantify the interjoint coordination pattern. A mixed-model analysis of variance was used to compare the difference among variables. Muscle strength in the vastus femoris and biceps femoris of the affected side of the patient group was significantly decreased, compared with that of the healthy control. Higher variability of the knee-ankle interjoint coordination was observed in the affected side during stair walking in individuals with ACL-R than the healthy control. The findings suggested that the variation in interjoint coordination patterns between the patient group and control group was more distinct at a high stair height than a lower stair height. Inadequate muscle strength could affect the neuromuscular control and could not provide stability at the joints, which increases the variability of interjoint movement and changes the interjoint coordination.
