Assessment of isokinetic peak torque reliability of the hip flexor, extensor, adductors and abductors muscles in female soccer players from 14 to 25 years old

BACKGROUND: The aim of this study was to evaluate test-retest reliability of concentric flexor, extensor, abductor and adductor muscular isokinetic hip torques in female soccer players. METHODS: Sixteen highly-trained female soccer players were evaluated. Isokinetic dynamometer assessment was performed at 30 degrees/s and 150 /s concentrically. The muscles tested were hip flexor (Fl), extensor (Ext), adductor (Add) and abductor (Abd). The reproducibility of the measured peak torque (PT) was analyzed by using the intraclass correlation coefficient (ICC). The difference in PT between the first and second tests was tested using Student's t-test. RESULTS: The ICC for the observed PT values revealed moderate to high reproducibility (ranging from 0.55 to 0.76) for the hip Fl and Ext measurements at 150 degrees/s and for Add and Abd measurements at 30 and 150 /s. For the hip Fl and Ext measurements at 30 degrees/s the ICC was poor. CONCLUSIONS: The isokinetic assessment of the concentric PT values generated by the hip Fl and Ext and Add and Abd is moderate to highly reproducible, when assessed at the highest test velocity (150 degrees/s). The test-retest reliability of hip isokinetic strength measures seems to be affected by the type muscle and test velocity.