Hip Stability Isometric Test (HipSIT): Concurrent Validity and Reference Values for CrossFit® Participants

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• The Hip Stability Isometric Test (HipSIT) is a practical clinical tool for evaluating posterolateral hip muscle function.
• Limited data exists on HipSIT validity in high-intensity training populations like CrossFit® athletes.

Purpose of the Study:

• To determine the concurrent validity of the HipSIT against isokinetic assessments in CrossFit® participants.
• To characterize posterolateral hip muscle performance using HipSIT, considering sex and limb dominance in this population.

Main Methods:

• A cross-sectional study involving 111 CrossFit® participants.
• Posterolateral hip muscles assessed via HipSIT using a hand-held dynamometer.
• Isokinetic assessment (Biodex System® 4 Pro) measured hip extensor and abductor peak torque and work at 60°/s.

Main Results:

• Significant positive correlations (Spearman's rho = 0.36–0.49) found between HipSIT and isokinetic measures.
• Bland-Altman analyses indicated good agreement between the two assessment methods.
• HipSIT performance was significantly higher in males than females and in dominant versus non-dominant limbs.

Conclusions:

• The HipSIT demonstrates concurrent validity for assessing posterolateral hip muscle performance in CrossFit® athletes.
• Findings support the clinical use of HipSIT for this population.
• Reference values should consider sex-based and limb-dominance-based differences.