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

BACKGROUND: 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. OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.