Introduction: The design and selection of lower-limb prosthetic devices is currently hampered by a shortage of evidence to drive the choice of prosthetic foot parameters. We propose a new approach wherein prostheses could be designed, specified, and provided based on individualized measurements of the benefits provided by candidate feet. In this manuscript, we present a pilot test of this evidence-based and personalized process.
Methods: We previously developed a "prosthetic foot emulator," a wearable robotic system that provides users with the physical sensation of trying on different prosthetic feet before definitive fitting. Here we detail preliminary demonstrations of two possible approaches to personalizing foot design: 1) an emulation and test-drive strategy of representative commercial foot models, and 2) a prosthetist-driven tuning procedure to optimize foot parameters.
Results: The first experiment demonstrated large and sometimes surprising differences in optimal prosthetic foot parameters across a variety of subjects, walking conditions, and outcome measures. The second experiment demonstrated a quick and effective simple manual tuning procedure for identifying preferred prosthetic foot parameters.
Conclusions: Emulator-based approaches could improve individualization of prosthetic foot prescription. The present results motivate future clinical studies of the validity, efficacy, and economics of the approach across larger and more diverse subject populations. Clinical Relevance: Today, emulator technology is being used to accelerate research and development of novel prosthetic and orthotic devices. In the future, after further refinement and validation, this technology could benefit clinical practice by providing a means for rapid test-driving and optimal selection of clinically available prosthetic feet. (J Prosthet Orthot. 2022;34:202-212)
The principles of evidence-based practice and personalized medicine are transforming modern-day health care. Within the field of prosthetics, however, the selection, prescription, and provision of prosthetic feet rely on craftsmanship despite a growing body of scientific literature, which provides some evidence that could be used to support clinical decision making. Evidence-based practice calls for "integrating individual clinical expertise and patient values with the best available evidence from systematic research, to provide the best clinical care," and personalized medicine calls for this evidence to be interpreted in light of both qualitative characteristics and quantitative test results from individual patients. However, when patients with lower-limb amputation are evaluated for the prescription of a prosthetic foot, current processes allow minimal opportunities to collect the data necessary to make such individualized assessments and decisions. Producing the evidence required for objective decision-making is challenging given the complexity of patients' needs and the broad spectrum of prosthetic foot functionalities, which is rapidly expanding due to technological advancement. Although recent advancements in advanced robotic prosthetic foot design suggest that it is possible to normalize gait for persons with lower-limb amputation, results have been inconsistent across studies and individuals, have been limited to relatively young and mobile patients, and have not addressed how comorbidities and other functional limitations impact gait performance. Furthermore, there are many different prosthetic feet available, each with variations in size, stiffness, and other parameters, and the cost of these feet varies across three orders of magnitude. As a result, persons with lower-limb amputation continue to be disadvantaged as compared with persons without amputation, and cost/benefit tradeoffs for prosthetic design remain poorly understood.