Proprioceptive and behavior impairments in individuals with anterior cruciate ligament reconstructed knees

OBJECTIVE: To assess sensory deficits and their effects on proprioceptive and motor function in patients who had undergone unilateral anterior cruciate ligament (ACL) reconstruction. DESIGN: Four evaluations were conducted: (1) joint position perception of the knee for predetermined angles (0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees ); (2) threshold for detection of passive knee motion at 0 degrees, 15 degrees, 30 degrees, 45 degrees, and 60 degrees moving into flexion and at 15 degrees, 30 degrees, 45 degrees, and 60 degrees moving into extension; (3) latency onset of hamstring muscles; and (4) postural control during upright double- and single-leg stance. SETTING: Movement laboratory in Brazil. PARTICIPANTS: Ten participants who had surgical reconstruction of the ACL (reconstructed group) and 10 participants without knee injury (control group). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Absolute error, angular displacement, hamstring muscles latency, and mean sway amplitude. RESULTS: Individuals with a reconstructed knee showed decreased joint position perception, a higher threshold for detection of passive knee motion, longer latency of hamstring muscles, and decreased performance in postural control. CONCLUSIONS: After lesion and ACL reconstruction, sensory and motor behavior changes were still observed. This may be because of the lack of proprioceptive information resulting from the ACL lesion and/or substitution of ACL by the graft.