The purpose of this study was to examine the relationship between knee muscle strength, including RFD, and psychological readiness to return to sport in high school and college athletes 4 months after ACLR.
In this study, high school and college athletes who underwent ACLR at a single hospital and subsequently had postoperative physical therapy in the rehabilitation department of the same institution were evaluated 4 months postoperatively. Knee extensor and flexor muscle strength was measured using the BIODEX system during isokinetic movements of 60°/s and 180°/s. RFD was also measured during isometric knee extension at 90 degrees of knee flexion. Symmetry between the reconstructed and uninvolved limb was assessed using the Limb Symmetry Index (LSI). In addition, Anterior Cruciate Ligament-Return to Sport After Injury (ACL-RSI) scale was completed to assess psychological readiness. Data were analyzed for correlation with ACL-RSI and independent variables (LSI of muscle strength, LSI of RFD, and age). Stepwise multiple regression analysis was also used to model the relationship between ACL-RSI scale score and the independent variables. All significance levels were set at 5%.
A total of 65 athletes participated in this study, with an average age of 18.3 years. There was a weak positive correlation between ACL-RSI scale score and LSI of knee extensor muscle strength (60°/s, 180°/s), LSI for knee flexor muscle strength (180°/s) and isometric knee extension RFD. There was a weak negative correlation between ACL-RSI and age. Multiple regression analysis showed that RFD was the most important predictor of ACL-RSI scale score.
RFD was an important factor related to psychological readiness in young athletes 4 months after ACLR. In addition, age and isokinetic knee strength were associated with ACL-RSI scale score.
It is important to measure RFD in addition to knee torque to evaluate and improve psychological readiness in young athletes 4 months after ACLR.
Rate of Force Development
ACL-RSI
