Background: Functional performance tests (FPT) have been used with athletes following an injury to determine readiness to return-to-play (RTP), usually using limb symmetry indices to the contralateral limb or a baseline score. There is not a consensus as to which criterion scores are best compared.

Hypothesis/purpose: This study aimed to compare common functional performance test scores from injured athletes at the time of release to RTP to both preseason baseline scores and to the contralateral limb. It was hypothesized that using baseline scores for comparison would be more responsive to residual deficits following injury than using the contralateral limb.

Study design: Prospective longitudinal cohort study.

Methods: High school athletes (n=395) from all varsity sports completed a battery of FPTs including the Y-Balance Test (YBT), single limb hop tests and T-Test for agility (TT) during their preseason to establish baseline data. Injured athletes (n=19) were re-tested using all FTP's again at the time of RTP. Paired t-tests were used to detect if significant (p\<0.05) residual deficits were present at time of RTP when compared to baseline and to contralateral scores on FPTs.

Results: Differences in YBT scores were found in the anterior direction only (p=0.021) when comparing RTP to preseason, but there were no differences when compared to RTP data for the contralateral limb. Differences were detected with the single leg hop test (p = 0.001) when comparing the RTP to preseason and were also detected in both the single leg hop (p= 0.001) and triple hop (p=0.018) when compared to the contralateral limb. Differences in TT scores were detected when comparing RTP to preseason for cutting first with both the unaffected (p = 0.019) and affected (p = 0.014) limbs.

Conclusions: The YBT in the anterior direction and the TT are better able to detect residual deficits when comparing RTP to preseason scores. Hop tests are better able to detect deficits when compared to the contralateral limb. These results could make preseason testing more efficient when creating a reference for determining RTP readiness following lower extremity injury.