Foot Pressure Pattern During Walking in Individuals with Anterior Cruciate Ligament Injury

Background: We evaluated foot pressure distribution during walking in individuals with anterior cruciate ligament (ACL) injury. Methods: Our study included 24 ACL-deficient patients and 22 healthy young adults as controls. The former group was divided into the dominant-side ACL-deficient group (n = 17) and the nondominant-side ACL-deficient group (n = 7). The following parameters were calculated from the path of the center of pressure (COP) on a foot pressure distribution system: percentage of COP (% COP; the ratio of anteroposterior COP path length to foot length), percentage of COP locus area (% CLA; the ratio of the area encompassed by the COP path and a line between the start and end points of the COP path to foot area), and the value of maximum amplitude of COP (MACOP; the maximum perpendicular length from the COP path to a line between the start and end points of the COP). Results: In the nondominant-side ACL-deficient group, % COP (P = .026), % CLA (P = .001), and MACOP (P = .012) on the injured side were significantly lower than those in the nondominant leg side of the control group. No significant differences were found between the dominant-side ACL-deficient group and the control group. Conclusions: Shortening of the COP trace in the nondominant-side ACL-deficient group may be associated with knee flexion during walking at heel contact. Because the parameters used herein can be obtained easily, repetitively, and quantitatively, they should be used in evaluating the gait of patients with ACL-deficient knees.