Hip flexion contractures are a common complication in disabled patients. However, no previous study has examined reduced hip motion during gait. This retrospective analysis evaluates the relationship between the degree of hip flexion contracture found on static testing and the degree found during gait and also assesses the strength of the association between hip flexion contractures and compensatory mechanisms such as anterior pelvic tilting, increased knee flexion, and decreased contralateral step length. Clinical and quantitative gait laboratory data were obtained from 41 consecutive patients with mostly neurologically based impairments who presented with bilateral hip flexion contractures on Thomas testing (82 limbs). Correlation studies demonstrated a relatively weak association between the degree of peak hip extension during gait and hip flexion contracture by Thomas testing (r = 0.41, P < 0.0001). Limited hip extension was most closely associated with anterior pelvic tilting (r = 0.60, P < 0.0001), whereas Thomas test measurements yielded a correlation with anterior pelvic tilt of only r = 0.36 (P< 0.001) and were insignificant predictor variables of anterior pelvic tilting in regression analysis. Thus, peak hip extension and anterior pelvic tilting assessed during gait were poorly associated with the static Thomas test measurements, and anterior pelvic tilt was most strongly correlated with reduced hip extension during gait compared with the other compensatory mechanisms.