Objective: To evaluate the feasibility of fixed-width beam walking for assessing balance in lower limb prosthesis users.
Subjects: Lower limb prosthesis users.
Methods: Participants attempted 10 walking trials on three fixed-width beams (18.6, 8.60, and 4.01 wide; 5.5 m long; 3.8 cm high).
Main measures: Beam-walking performance was quantified using the distance walked to balance failure. Heuristic rules applied to each participant's beam-walking distance to classify each beam as "too easy," "too hard," or "appropriately challenging" and determine whether any single beam provided an appropriate challenge to all participants. The number of trials needed to achieve stable beam-walking performance was quantified for appropriately challenging beams by identifying the last inflection point in the slope of each participant's trial-by-trial cumulative performance record.
Results: In all, 30 unilateral lower limb prosthesis users participated in the study. Each of the fixed-width beams was either too easy or too hard for at least 33% of the sample. Thus, no single beam was appropriately challenging for all participants. Beam-walking performance was stable by trial 8 for all participants and by trial 6 for 90% of participants. There was no significant difference in the number of trials needed to achieve stable performance among beams ( P = 0.74).
Conclusion: Results suggest that a clinical beam-walking test would require multiple beams to evaluate balance across a range of lower limb prosthesis users, emphasizing the need for adaptive or progressively challenging balance tests. While the administrative burden of a multiple-beam balance test may limit clinical feasibility, alternatives to ease this administrative burden are proposed.
Keywords: Postural balance; amputee; falls; rehabilitation; walking.