Assessment of texture discrimination ability at the sole of the foot in subjects with chronic stroke compared with young and elderly subjects with no neurological deficits: a reliability and validity study

Purpose: To examine validity and test–retest reliability of a sensory test developed to evaluate ability of elderly subjects with/out a stroke to discriminate between textures with the sole of their foot. Methods: Subjects poststroke, old adults and young subjects were tested twice. Twelve materials relevant to foot function (e.g., gravel, sand) were used. Blindfolded subjects were requested to discriminate with the sole of each foot one outstanding texture among three textures presented in each of 12 subtests. ANOVA, ICC and Bland–Altman tests were used to determine group/leg differences and test-retest reliability. Results: Discrimination ability of the involved lower extremity poststroke is significantly reduced. Ability in individuals with no neurological impairment is age related. Good test–retest (ICC = 0.81) reliability was demonstrated for the impaired foot of subjects poststroke. The 95% repeatability ranges were age related with the highest range demonstrated for the involved foot poststroke. A significant fair negative correlation was demonstrated between texture discrimination ability and tactile detection threshold measured by Semmes–Weinstein monofilaments for the involved foot in poststroke subjects. Conclusion: This newly developed assessment tool demonstrates concurrent and known-groups validity and is reliable for determining texture discriminative ability of the foot in individuals post-stroke and in older adults with no neurological impairment.Implications for rehabilitation The texture discrimination test presented here is a valid and reliable tool, providing quantitative assessment of sensory function at the sole of the foot in older adults with no neurologic deficits and in subjects poststroke. Lower extremity texture discrimination test is easy to administer in the clinic and might suggest directions for individually tailored, lower extremity, sensory retraining protocols.