The Persian version of locomotor capabilities index: translation, reliability and validity in individuals with lower limb amputation

Abstract

To translate the Locomotor Capabilities Index (LCI-5) to Persian and to assess its psychometric properties when applied to a sample of people with lower limb amputation (LLA). The LCI-5 was administered to 106 Persian speaking people with LLA to determine its internal consistency, item-subscale correlation, test-retest reliability and floor and ceiling effects. To assess the construct validity, each participant's performance was measured using the Timed Up and Go (TUG) and 2-Minute Walk Test. Minimum Cronbach's alpha of 0.70 was exceeded by LCI-5 subscales. Item-subscale correlations after correction for overlap were higher than the cuff-off point of 0.40. The intraclass correlation coefficient was 0.96 for LCI-5 total index in test-retest reliability. LCI-5 showed significant correlation with TUG (r = -0.65, P < 0.01) and 2-Minute Walk Test (r = 0.71, P < 0.01). The LCI-5 mean scores were higher for individuals with unilateral below-knee amputation than participants with above-knee amputation (t = 2.71, P = 0.008) and for individuals with unilateral amputation who do not use walking aids than those who use (t = -4.27, P < 0.01). Floor effect was found for none of the patients with LLA while ceiling effect was reported for 23.6% of patients. The Persian version of LCI-5 has acceptable levels of internal consistency, item-subscale correlation, test-retest reliability and construct validity. To detect intervention effects, the LCI-5 should be used cautiously in population of physically active and young patients with LLA due to its high ceiling effects.