The relationship between vestibular sensory integration and prosthetic mobility in community ambulators with unilateral lower limb amputation

Objective. The modified Clinical Test of Sensory Interaction and Balance (mCTSIB) is used to clinically assess vestibular sensory integration (VSI), the process by which the central nervous system integrates vestibular afference to maintain balance. The rate and effects of impaired VSI (IVSI) on prosthetic mobility in people with lower limb amputation (LLA) is unknown. The objective of this study was to use the mCTSIB to classify VSI in active community ambulators with LLA and to examine the relationship between IVSI and prosthetic mobility, as measured by the Component Timed Up and Go (cTUG) test. Methods. This was a cross-sectional study with a convenience sample of 130 community ambulators with unilateral LLA. Classification of VSI was determined based on a time-based pass/fail mCTSIB performance. Participants were classified as having normal sensory integration (NSI) if they could balance for 30 seconds in every mCTSIB condition. Participants who failed condition 4 exclusively were classified as IVSI. Prosthetic mobility, as measured by the cTUG, was compared between NSI and IVSI groups. Results. Of the 130 participants, 29 (22%) were classified as IVSI and 95 (73%) were classified as having NSI. Prosthetic mobility significantly differed between IVSI and NSI groups, with IVSI participants performing all components of the cTUG significantly slower. Medium to large effect sizes were found between groups during cTUG. Conclusions. These results suggest that 1 in 5 community ambulators with LLA have IVSI, with associated limitations in balance confidence and prosthetic mobility. Impact. The ability to integrate vestibular information was found to have a strong relationship with prosthetic mobility in active community ambulators with LLA, especially with performing a 180-degree step turn. Physical therapists can use the mCTSIB to classify sensory integration during prosthetic rehabilitation and develop an appropriate balance intervention. Lay Summary. Active adults with LLA can use information from their senses to maintain their standing balance. Adults with LLA who have difficulty balancing on foam with closed eyes were slower to get in and out of a chair, walk, and perform a 180-degree step turn.