Reliability of physical examination tests for assessing hip flexor flexibility: A systematic review and meta-analysis.

OBJECTIVE

To evaluate the reliability of physical examination tests used for assessing hip flexor flexibility, including the Modified Thomas Test (MTT), Thomas Test, Reactive Hip Flexor Test, Swing Test, and Falcon Test.

LITERATURE SURVEY: A systematic search was conducted across multiple databases (PubMed, CINAHL, SPORTDiscus, Scopus, Web of Science, and Rehabilitation & Sports Medicine Source) up to March 2024.

METHODOLOGY: Studies were included if they reported intra- or interrater reliability outcomes for clinical tests assessing hip flexor flexibility, using recognized statistical measures such as the intraclass correlation coefficient (ICC), SEM, minimal detectable change, or Bland-Altman plots. The methodological quality of included studies was assessed using the Quality Appraisal of Reliability Studies checklist. Meta-analyses were performed using random-effects models to calculate pooled ICC values for intra- and interrater reliability, with subgroup analyses based on the type of flexibility test.

SYNTHESIS: The meta-analysis included 27 studies, comprising 1056 participants. The overall pooled intrarater ICC was 0.90 (95% CI, 0.85-0.95) in 888 participants, indicating excellent reliability, and the interrater ICC was 0.80 (95% CI, 0.71-0.88) in 665 participants, reflecting good reliability. However, substantial heterogeneity was observed for both intrarater (I2 = 99%) and inte-rater (I2 = 98.3%) analyses, particularly for the MTT and Thomas Test. In contrast, the Thomas Test demonstrated the lowest interrater reliability (ICC, 0.62 [95% CI, 0.46-0.78]) with significant between-study variability.

CONCLUSIONS

Physical examination tests for hip flexor flexibility demonstrate generally high intra- and interrater reliability. However, considerable methodological variability was identified, particularly for the MTT and Thomas Test, suggesting a need for standardized protocols. Newer tests, such as the Falcon and Swing Tests, showed excellent reliability but require further validation.