RELIABILITY OF THE SUBJECTIVE EVALUATION OF PATIENT BIOMECHANICS AND MOTOR CONTROL DURING AN ANTERIOR CRUCIATE LIGAMENT RETURN TO SPORT ASSESSMENT

To determine the inter-rater reliability of multiple skilled assessors to rate the subjective biomechanical and motor control risk factors exhibited by patients undergoing a structured post-operative anterior cruciate ligament (ACL) Return to Sport (RTS) assessment. Video data demonstrating the performance of 30 ACL reconstruction patients who underwent a standardized ACL RTS assessment was distributed to four skilled raters (two Physical Therapists and two Athletic Trainers). The ACL RTS was developed based on 18 previously published and validated tests of strength (leg press, single leg squat, hamstrings, hip abduction), power (tuck jumps, single leg hop, triple hop, cross-over hop, 6m hop, lateral hop, medial hop, vertical jump, drop-down jump, burpees), proprioception/balance (Y balance test: anterior, posteromedial, posterolateral), and agility/endurance (Lower Extremity Functional Test [LEFT]). The patients’ double and single limb performance of each test was subjectively evaluated independently by each rater for hip/pelvic stability, knee flexion, varus/valgus, shock absorption, trunk stability, power, and body control on a three-point scale (high [1], medium [2], low risk [3]) using pre-defined criteria. The raters had previously been trained on these criteria. Each rater scored the patients on all 18 tests using each of the subjective categories. For each patient, the scores (1-3) for each subjective component were added to attain a total subjective score for each of the 18 tests. Total scores for each of the 18 tests were used to calculate the Kendall's Coefficient of Concordance across all four raters. The included patients were 53% female and a mean of 19.8 ± 7.7 years old with a mean BMI of 24.9 ± 4.3 kg/m2. Mean time from ACL reconstruction surgery to the ACL RTS assessment was 8.9 ± 1.5 months. The dominant limb was reconstructed in 87% of patients. The majority of the tests demonstrated substantial agreement1 across the four raters with Kendall's Coefficients of Concordance ranging from 0.61 to 0.77. The posteromedial and posterolateral components of the Y Balance test had lower coefficients (0.57 – 0.61). There were differences in the concordance within the strength tests: leg press had near perfect agreement (non-/surgical limb = 0.81, 0.86), hamstrings and hip abduction strength testing had moderate agreement (0.33 – 0.68). This study has demonstrated the substantial agreement of a subjective rating system to evaluate the biomechanical and motor control risk patterns of ACL reconstruction patients undergoing a standardized return to sport assessment. Multiple raters, both Physical Therapists and Athletic Trainers, who were similarly trained on the subjective evaluation of these risk patterns, were able to substantially agree on the patients’ risk profile across 14 of the 18 different tests of physical function. Further work is required to improve the inter-rater reliability of the Y balance test and hamstrings/hip strength evaluations. This demonstrates the ability to disseminate the use of this standardized ACL RTS protocol as long as the rehabilitation specialists administering and scoring the assessment have been adequately trained on the subjective assessment component.