Single-leg hop distance normalized to body height is associated with the return to sports after anterior cruciate ligament reconstruction

PURPOSE: To investigate the relationship between single-leg hop distance (SLHD), normalized body height, and return-to-sports (RTS) status after anterior cruciate ligament reconstruction (ACLR) and to identify the cut-off value for SLHD on the operated side. METHODS: Seventy-three patients after primary ACLR (median 13.5 months) participated in this cross-sectional study. Participants were divided into ‘‘Yes-RTS’’ (YRTS) or ‘‘No-RTS’’ (NRTS) groups based on a self-reported questionnaire. SLHD was measured, and the limb symmetry index (LSI) and SLHD (%body height) were calculated. A minimum p-value approach was used to calculate the SLHD cut-off points (%body height) on the operated side that were strongly associated with the RTS status. Logistic regression analysis was used to analyse the association between RTS status and SLHD cut-off point (%body height). Isokinetic strength and Tampa scale for kinesiophobia (TSK) were measured as covariates. RESULTS: Among 73 patients, 43 (59%) were assigned to the YRTS and 30 (41%) to the NRTS group. The 70% body height cut-off point for SLHD on the operated side was most strongly associated with RTS status. In a logistic regression analysis including other covariates, SLHD (%body height) < 70% and TSK were negatively associated with RTS status. Except for two participants, the LSI of the SLHD exceeded 90% and there was no significant association between the LSI of the SLHD and RTS status. CONCLUSION: Even after improvement in the LSI of the SLHD, planning rehabilitation with the goal of achieving SLHD over 70% body height may be important for supporting RTS after ACLR. LEVEL OF EVIDENCE: Cross-sectional study, Level IV