TP8.1 A Visual Analog Scale for Single-Leg Squat Assessment Demonstrates Reliability in Patients with Hip Pathology

Abstract

Abstract Introduction Accurate assessment of hip function is critical for guiding rehabilitation in patients with hip pathology. The single leg squat test (SLST) is commonly used to evaluate movement quality in this population. However, standardized SLST scoring methods have yet to be identified, and existing methods rely on categorical scoring systems that may lack sensitivity. This study aimed to evaluate the reliability, construct validity, and responsiveness of a continuous visual analog scale (VAS) for SLST assessment in patients with hip pain. Methods Twenty-four participants (age 15.8 ± 2.9 years) with hip pain were assessed using a sliding, 100-point VAS-based SLST scoring system evaluating trunk deviation, hip adduction, and lower extremity internal rotation for both legs. Overall VAS score was calculated by averaging the three components, where lower scores corresponded to less deviation from a perfect SLST. Intra- and inter-rater reliability for two trained raters was determined using intraclass correlation coefficients (ICCs). Relationships between VAS scores, objective force output obtained via dynamometry (hip extension, external rotation, abduction) and patient-reported outcomes (iHOT-12) were determined using Spearman’s correlation coefficients. Responsiveness was evaluated in eight participants with follow-up testing at 6–8 weeks following physical therapy. Results The VAS demonstrated moderate to strong intra-rater reliability (ICC: 0.65–0.92) and fair to strong inter-rater reliability (ICC: 0.43–0.81) across all components. Better baseline VAS scores were associated with greater baseline strength (ρ = -0.14 to -0.48) and patient-reported function (ρ = -0.23 to -0.41). All correlations were significant (p < 0.001). At follow-up, 78.6% of legs that demonstrated improved VAS scores also showed improvements in at least two strength measures, with 93.8% showing improvement in at least one strength measure. Changes in VAS score did not consistently align with iHOT-12 scores at follow-up. Conclusion The proposed VAS tool for SLST assessment demonstrates adequate reliability and preliminary evidence of validity in patients presenting with hip pain. The VAS appears responsive to changes in objective force output and may reflect clinically relevant changes in strength. Given its simplicity and continuous scoring approach, the VAS may serve as a practical adjunct for tracking rehabilitation progress in hip preservation populations.