Changes In Psychological Readiness And Quadriceps Strength From Early To Late Rehabilitation Following Acl Reconstruction

Psychological readiness for return to sport has previously been associated with quadriceps strength during late-stage anterior cruciate ligament reconstruction (ACLR) rehabilitation. However, it is unclear if improvements in quadriceps strength are associated with improvements in psychological readiness from early to late rehabilitation. PURPOSE: The purpose of this study was to examine the relationship between longitudinal changes in psychological readiness for sport and isokinetic thigh muscle strength from early (3-5 mo.) to late (7-9 mo.) rehabilitation after ACLR. METHODS: Thirty-two individuals with primary, unilateral ACLR (11 females, age = 20.8 ± 4.9 years) were included. Participants completed testing 3-5 months (4.0 ± 0.3 mo.) and 7-9 months (8.3 ± 0.8 mo.) after ACLR. Participants completed the ACL return to sport after injury survey (ACL-RSI) to assess psychological readiness for sport and bilateral isokinetic knee extension strength assessments at 60 deg/s. Peak knee extension torque (PT) was normalized to body mass and a limb symmetry index (LSI) was calculated. RESULTS: Repeated measures ANOVAs indicated that, after controlling for sex and age, there was a significant overall model indicating that both ACL-RSI scores (p = 0.003, R2 = 0.216) and LSI ( p < 0.001, R2 = 0.407) improved over time. Pearson’s correlation revealed that absolute change over time in ACL-RSI was related to change in PT LSI (p = 0.050, R2 = 0.126). However, the percent change in ACL-RSI was not related to the percent change in PT LSI (p = 0.575, R2 = 0.011). CONCLUSION: The findings suggest that there is a weak relationship between the absolute change in psychological readiness to return to sport and knee extension torque symmetry between early and late stages of rehabilitation. Therefore, it may be beneficial for clinicians to assess psychological readiness independently from isokinetic quadriceps strength when considering patient progress in rehabilitation.