Does lower limb amputation affect lateralization and motor imagery ability in prosthesis users and nonusers? A cross-sectional, assessor-blinded study.

Abstract

Amputation leads not only to limb loss but also to alterations in body representation, motor planning, and sensorimotor integration. Prosthesis use may help preserve these representations; however, its influence on cognitive motor processes such as laterality judgment and motor imagery remains unclear. This study aimed to examine the effects of lower limb amputation (LLA) and prosthesis use on laterality judgment performance and motor imagery ability compared with able-bodied individuals. Three groups participated: prosthesis users (PU) and nonprosthesis users (N-PU) with acquired unilateral LLA at or above the below-knee level, and normally limbed controls. Participants completed a laterality judgment task (reaction time and accuracy), the Vividness of Movement Imagery Questionnaire-2 (VMIQ-2), and the imagined Timed Up and Go (iTUG) test. Repeated measures ANOVAs, one-way ANOVAs, and independent samples t-test were conducted to analyze group differences. In the laterality task, N-PU participants demonstrated significantly longer reaction times than controls in the abstract condition for both the nonamputated (p = 0.001) and amputated sides (p = 0.004), along with lower overall accuracy (p = 0.035), whereas PU participants performed comparably with controls (p > 0.05). In the VMIQ-2, both amputee groups showed significantly reduced imagery vividness across all subscales compared with controls (p < 0.05); however, PU participants exhibited significantly greater kinesthetic imagery vividness than N-PU participants (p = 0.001). No significant difference was found between PU and controls in iTUG performance (p = 0.051). Prosthesis use appears to support the preservation of motor imagery ability and spatial representation in individuals with LLA. These findings emphasize the potential cognitive-motor benefits of prosthetic integration and support the inclusion of imagery-based assessments in rehabilitation programs.