Preliminary investigation of the lateral postural stability of spinal cord-injured individuals subjected to dynamic perturbations

Study Design: A study of the impact of spinal cord injury (SCI) on seated b alance was conducted by comparing the results obtained from experiments wit h able-bodied and SCI subjects. Objectives: The purpose of this preliminary study was to examine the latera l postural stability of seated individuals with SCI in a dynamic environmen t. Setting: Experiments were conducted at the Cleveland Clinic Foundation in C leveland, Ohio. Methods: Controlled perturbations were applied to each subject, seated in a wheelchair, through the use of a servo-controlled tilt platform. The platf orm was rotated so as to create disturbances similar in nature to those exp erienced in the frontal plane during left turns in a vehicle. Four quadripl egic, four paraplegic, and five able-bodied subjects participated in this s tudy. Kinematic information and center of pressure (COP) movement were reco rded. Results: None of the spinal cord-injured subjects was able to maintain his stability when exposed to the stronger perturbations, while all of the able -bodied subjects stayed uptight for all of the trials. On an individual bas is, injury level was not always indicative of balance. However, regression results suggest a correlation between ability to perform static leaning and dynamic balance (P < 0.001). Conclusions: SCI subjects lost stability under dynamic conditions even thou gh they were stable in the static situation. Initial results also raise som e questions about where and when external support may be needed. Informatio n of this nature could help to guide the design of new lateral supports wit h improved client acceptance.