Amputee gait performance symmetry may be affected by how prosthetic socket shape is captured: A preliminary investigation

Abstract

BACKGROUND: Socket fit is a critical determinant of comfort, mobility, and long-term prosthesis use in individuals with transtibial amputation. Traditional hand-casting techniques are labor-intensive and variable, whereas digital socket shape capture may improve reproducibility and consistency. However, its influence on gait performance remains an open question. OBJECTIVES: To compare gait performance measures in body support, forward propulsion, stability, and interlimb symmetry between digitally shaped sockets (DSS) and traditionally shaped sockets (TSS). STUDY DESIGN: Randomized Clinical Trial (RCT). METHODS: In this preliminary RCT (NCT05884203), 10 adults with unilateral transtibial amputation were assigned to receive a DSS or a TSS. After a 2-week acclimation, participants completed treadmill walking trials at their preferred speed. Ground reaction force and center of pressure data were analyzed to provide measures of body support, forward propulsion, stability, and interlimb symmetry. Socket fitting characteristics were assessed by the required number of sock plies. An exploratory analysis using linear mixed-effects regression was conducted to compare groups. RESULTS: Compared with the TSS group, the DSS group demonstrated reduced body support (p = 0.05, Hedges g = 1.03) and improved interlimb symmetry in body support (p = 0.04, g = 0.71) and propulsion (p = 0.04, g = 0.80). No consistent socket effects were observed for margin of stability. Fewer fitting socks were required in the DSS group (0-3 vs. 0-8 ply in TSS), suggesting a more consistent fit. CONCLUSIONS: Digital socket fabrication may promote more symmetrical gait and reduce variability in fitting compared with traditional casting. Although findings are preliminary, they highlight potential biomechanical and clinical benefits and warrant confirmation in larger, more diverse cohorts.