Context: Recently, attention in sports has been given to eccentric hip-muscle function, both in preventing musculoskeletal injuries and improving performance. Objective: To determine the key isokinetic variables of eccentric hip torque that predict the functional performance of women in the single-leg triple long jump (TLJ) and the timed 6-m single-leg hop (TH). Design: Within-subject correlational study. Setting: Musculoskeletal laboratory. Participants: 32 healthy women age 18–25 y. Intervention: The participants performed 2 sets of 5 eccentric hip-abductor/adductor and lateral/medial-rotator isokinetic contractions (30°/s) and 3 attempts in the TLJ and TH. Main Outcome Measurements: The independent variables were the eccentric hip-abductor and –adductor and medial- and lateral-rotator isokinetic peak torque, normalized according to body mass (Nm/kg). The dependent variables were the longest distance achieved in the TLJ normalized according to body height and the shortest time spent during the execution of the TH. Results: The forward-stepwise-regression analysis showed that the combination of the eccentric hip lateral-rotator and -abductor isokinetic peak torque provided the most efficient estimate of both functional tests, explaining 65% of the TLJ variance (P < .001) and 55% of the TH variance (P < .001). Conclusions: Higher values for eccentric hip lateral-rotator and hip-abductor torques reflected better performance. Thus, the eccentric action of these muscles should be considered in the development of physical training programs that aim to increase functional performance.
Keywords: biomechanics, dynamic knee valgus, hop tests, patellofemoral pain syndrome