Does the Concussion Clinican Examination Predict Post-Concussion Subsequent Musculoskeletal Injury?

Objective To identify post-concussion subsequent lower extermity musculoskeletal injury predictors from a clinical concussion assessment. Background Emerging evidence has identified an elevated risk of subsequent lower extremity musculoskeletal injury (LE-MSK) in the year post-concussion. This approximately 2-fold elevated risk has been identified in diverse populations including high school, college, professional sports and military populations. While persistent impairments in postural control are a speculated mechanism, these assessments require instrumented biomechanical measures; thus, there are currently no clinically feasible predictors which have been identified. Design/Methods Eighty three NCAA Division I student-athletes (51.8% female, ht: 1.75 +/− 0.12 m, wt: 76.2 +/− 20.1 kg) who had suffered a sports related concussion (LOC: 7.5%, PTA: 12.2%) with baseline data were assessed within 72 hours post-concussion were included in this retrospectic study. The clinical examination consisted of the Balance Error Scoring System (BESS), Standard Assessment of Concussion (SAC), Clinical Reaction Time (CRT), King-Devick (KD) and the Immediate Post-Concussion Assessment and Cognitve Test (ImPACT) composite values. Change scores (Δ) from baseline to acute post-concussion served as predictors to identify subsequent LE-MSK with a step wise binary logistic regression. Results The subsequent LE-MSK rate was 72.3% (60/83). The overall model failed to identify a predictive relationship between change scores and subsequent injury risk (r2 = 0.242, p = 0.458). Exploratory testing failed to identify any significant individual predictors of subsequent LE-MSK: BESS: Δ = −0.35 errs, p = 0.964; SAC: Δ = −0.55, p = 0.239; ImPACT Verbal Memory: Δ = −0.53, p = 0.324; ImPACT Visual Memory: Δ = −5.6, p = 0.750; ImPACT Motor Speed: Δ = −2.81, p = 0.070; ImPACT Reaction Time: Δ = 0.042 sec, p = 0.164; CRT: Δ = 12.2 ms, p = 0.564; and KD: Δ = 2.8 sec, p = 0.607. Conclusions None of the common clinical concussion assessments were a significant predictor of subsequent LE-MSK potentially due to a high injury rate (72.3%). Future research should continue attempts to idenify clinically feasible predictors to allow clinicians to identify at-risk athletes to engage injury prevention strategies to reduce subsequent LE-MSK.