To identify post-concussion subsequent lower extermity musculoskeletal injury predictors from a clinical concussion assessment.

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.

Eighty three NCAA Division I student-athletes (51.8% female, ht: 1.75 +/- 0.12m, wt: 76.2 +/- 20.1kg) 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.

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=-.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.

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.