Related Experiment Video
Updated: Jun 28, 2025

Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation
Published on: December 13, 2024
Reliability of a qualitative movement assessment tool during a single-leg triple hop landing
Eli Epstein1, Casey Huse1, Meredith Link1
1Children's Hospital of Philadelphia, PA, USA.
Objective:
Assess inter- and intra-rater reliability of the Qualitative Analysis of Single Leg Squat (QASLS) during a single-leg triple hop landing in subjects following anterior cruciate ligament reconstruction (ACLR). Explore if differences in reliability existed between novice and experienced clinicians. Determine if QASLS scores differed between the surgical and nonsurgical limbs.
Design:
Repeated Measures.
Participants:
20 subjects ≥6 months post-ACLR.
Methods:
Subjects were recorded performing a single-leg triple hop bilaterally. Videos were independently rated by five raters (2 physical therapists and 3 physical therapy students). Intraclass correlation coefficient (ICC) was calculated to measure reliability of the QASLS on the surgical limb. Wilcoxon signed-rank test was utilized to assess if differences in QASLS scores existed between limbs.
Results:
The cumulative inter-rater reliability was moderate (ICC (2,1): 0.703) and the cumulative intra-rater reliability was good (ICC (3,1): 0.857). Little difference was found between experienced and novice raters for inter- and intra-rater reliability. There was no statistically significant difference in QASLS scores between limbs (P = 0.64).
Conclusion:
The QASLS tool offers moderate inter- and good intra-rater reliability for evaluating movement quality during a single-leg triple hop landing, irrespective of rater experience. Additionally, there was no observed difference in QASLS scores between surgical and nonsurgical limbs.

