Test re-test reliability of single and multijoint strength properties in female Australian footballers

Purpose: To examine the test re-test reliability of isometric maximal voluntary contractions (MVC) of hip adduction (ADD_ISO), hip abduction (ABD_ISO), and multijoint leg extension (SQUAT_ISO) in sub-elite female Australian footballers. Methods: Data were collected from 24 sub-elite female Australian footballers (age 22.6 ± 4.5 years; height 169.4 ± 5.5 cm; body mass 66.6 ± 8.0 kg; 4.5 ± 4.4 years sport-specific training; 2.5 ± 2.0 years unstructured resistance training) from the same club on two non-consecutive days. Participants performed three isometric MVCs of ADD_ISO, ABD_ISO, and SQUAT_ISO. The SQUAT_ISO was performed at 140° knee flexion with a vertical trunk position and ADD_ISO and ABD_ISO measures were performed in a supine position at 60° of knee flexion and 60° hip flexion. Reliability was assessed using paired t tests and the intraclass correlation coefficient (ICC) with 95% confidence intervals (CI), typical error (TE), and coefficient of variation (CV%) with 95% CI. Results: SQUAT_ISO peak force (ICC.95; CV% 4.1), ABD_ISO for left, right, and sum (ICC.90–.92; CV% 5.0–5.7), and ADD_ISO for left, right, and sum (ICC.86–.91; CV% 6.2–6.9) were deemed acceptably reliable based on predetermined criteria (ICC ≥.8 and CV% ≤ 10). Conclusion: SQUAT_ISO, ABD_ISO, and ADD_ISO tests demonstrated acceptable reliability for the assessment of peak force in sub-elite female Australian footballers, suggesting these assessments are suitable for muscle strength testing and monitoring adaptations to training.