The Smart Adaptive Socket System and Its Impact on Transtibial Prosthesis Users: A Mixed Methods Research Study

An intimate and well-fitting prosthetic socket is critical to supporting user independence, ambulation efficiency, and reduced pain and skin breakdown. As many with limb loss endure daily and hourly volume fluctuations, maintaining optimal socket fit is especially difficult. This convergent mixed methods self-controlled multi-case study evaluated the Smart Adaptive Socket System (SASS), a prototype capable of improving socket fit by accommodating and stabilizing volume fluctuations within the residuum. Subjects’ existing prostheses were used as controls. StepWatch activity monitors, Prosthesis Evaluation Questionnaires (PEQ), and open-ended interviews provided data for this review. Seven transtibial amputees participated in the study. On average, subjects took 23% more steps with the SASS. For the PEQ frustration and utility scales, there was a mean decrease with the SASS: 18.5 points and 8.3 points, respectively. Most (86%) preferred the SASS over their standard prosthesis. Qualitatively, subjects reported that SASS provided secure fit and confidence (n = 5), satisfactory comfort (n = 4), and a perceived benefit (n = 4). Four stated that the software was easily understood, while three dissented. Five felt that the system was too big, and four reported charging challenges. Quantitative and qualitative data were integrated to identify agreement or divergence. Positive qualitative themes were found to have a positive correlation for both frustration and utility, while negative themes were found to have weaker relationships for frustration and utility. Through the collection of multiple data types, this study gathered valuable user perspectives and usage data, helpful for further development and refinement of the prototype.