Prognostic Value Of Limb Loading During Early Functional Assessment For Predicting Later Jump Landing Performance Following Aclr

Bilateral bodyweight squats are exercises that can be safely completed to evaluate movement quality early in recovery following anterior cruciate ligament reconstruction (ACLR); while landing maneuvers are more appropriate at later stages of recovery. PURPOSE: Determine if limb loading during a squat and quadriceps strength of the ACLR limb and patient reported function at an interim stage of recovery is associated with landing performance at a later stage of recovery. METHODS: Forty-five patients (51.1% female, 20.4 ± 7.11 yrs) completed two testing sessions at 5.1 ± 1.42 months (Visit 1) and 8.3 ± 1.81 months (Visit 2) post-ACLR. At Visit 1, patients completed three sets of three bodyweight squats on a pressure mat while limb loading peak force (N) was recorded. Quadriceps peak torque (Nm) was collected via isokinetic dynamometry at 90°/sec. The ACL-Return to Sport after Injury Scale (ACL-RSI) was also collected at Visit 1. At Visit 2, patients completed the landing error scoring system (LESS) assessment. A binary score (Yes/No) was recorded if any of the following frontal errors were identified: 1) patella inline/medial to great toe at maximal knee flexion; 2) stiff landing/large knee valgus motion. A binary logistic regression was conducted with associated odds ratios (OR), a receiver operator characteristic curve, and associated area under the curve (AUC) with α ≤ 0.05. RESULTS: The binary logistic regression evaluating the Visit 1 predictors with the Visit 2 binary error score outcome was statistically significant (p < 0.01, R2 = 0.34, AUC = 0.86, 95% CI [0.74, 0.97]). Peak force (p < 0.05, OR = 0.99, 95% CI[0.98,0.99], Table 1) was a significant predictor in the model. CONCLUSION: Limb loading characteristics during a squat at an interim stage of recovery has the prognostic ability for early detection and possible intervention of risky movement patterns that may present later in recovery from ACLR. Table 1. - Predictor Variable Descriptive Statistics Variable Mean ± SD AUC 95% CI p-value Limb Loading Peak Force (N) 508.66 ± 132.06 0.81 0.66-0.96 0.003* Quadriceps Peak Torque (Nm) 108 ± 36.42 0.61 0.42-0.79 0.31 ACL-RSI 58.69 ± 23.38 0.32 0.13-0.51 0.09 Study was supported by funding from the Innovative, Developmental Exploratory Award (IDEA) research and development fund from the School of Education and Human Development at the University of Virginia and from the American College of Sports Medicine Biomechanics Interest Group (BIG).