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. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40798-020-00292-5.