Limits of stability in patients with vascular (due to diabetes) and nonvascular unilateral transtibial amputation: a cross-sectional study.

The aim of the study was to investigate the differences in the stability limits between patients with vascular and nonvascular unilateral transtibial amputation (UTA) and patients without amputation. Eighteen patients with UTA who used a prosthesis were divided into two groups: vascular (n=9) and nonvascular (n=9). Twenty-four patients without amputation served as the control group. Computerized dynamic posturography Smart EquiTest System, version 8.0 was used for measuring stability limits. The limits of stability test was used to assess the participants' ability to voluntarily sway to various locations in space. The measured parameters were maximum centre of gravity (COG) excursion, endpoint COG excursion and directional control. Single-factor analysis of variance and Bonferroni adjustment a posteriori tests was performed to investigate the differences between groups. The patients with vascular UTA had significantly lower endpoint COG excursion to oblique and forward direction compared with controls (P=0.017). In addition, the patients with vascular UTA had significantly lower maximum COG excursion to oblique and forward and to oblique and backward directions (P=0.031; 0.019). Patients with vascular UTA had significantly lower endpoint and maximum COG excursion to oblique and backward direction compared with patients with nonvascular UTA (P=0.30; 0.029). To summarize, patients with vascular UTA have substantially reduced limits of stability compared with patients without amputation and the patients with nonvascular UTA.