Background and purpose: Although surgical reconstruction of the anterior cruciate ligament (ACL) is commonly performed to increase stability of the knee, persistent changes in neuromuscular function have frequently been cited as contributing to disability. This study investigated single-leg standing balance in a sample of patients 10 to 18 months following reconstructive ACL surgery. In addition, the effect of leg dominance on standing balance was analyzed in a sample of subjects without knee injury. The validity and interrater reliability of a clinical method of measuring balance using observation were also determined.
Subjects: Seventy-eight subjects without knee injury and 17 patients following ACL surgery participated in the study after they had been screened for balance disorders.
Methods: Postural sway measurements were recorded during single-leg standing with the subjects' eyes open and closed. Simultaneously, two physical therapists graded each subject's performance using a simple ordinal scale.
Results: No differences were found between the dominant and nondominant legs of the subjects without knee injury or between the involved and noninvolved legs of the patients who had undergone ACL surgery. The interrater reliability was high, but limited concurrent validity was found.
Conclusion and discussion: The findings suggest that single-leg standing balance can be reliably evaluated by physical therapists. The single-leg standing balance test, however, may not provide information that assists clinicians in determining clinical change or functional level for patients following rehabilitation for ACL surgery.