Analysis of a Novel Prosthetic Foot Design: A Clinical and Biomechanical Evaluation

ABSTRACT Background Energy storage and return (ESR) prosthetic feet are the standard of care for individuals with Medicare Functional Classification Level K3 or K4, particularly in developed healthcare systems. While conventional ESR feet with J- or C-shaped carbon blades offer effective energy return, they often require high build heights and offer limited adjustability, which may restrict their use in specific patient populations. Objective The aim of the study was to evaluate the biomechanical and functional performance of a novel low-profile ESR prosthetic foot, featuring a unique load transmission system and adjustable heel components, in comparison to participants’ established ESR feet (everyday foot, EF). Study Design Different prosthetic feet were evaluated using a cross-sectional study design based on biomechanical tests and patient-reported evaluations. Methods Twelve experienced prosthesis users (6 transtibial [TTA], 6 transfemoral [TFA], K3–K4) completed a minimum 9-week accommodation period using the study foot (SF). Comparative assessments included instrumented gait analysis, Six-Minute Walk Test (6MWT), and patient-reported outcomes (PLUS-M, ABC scale, foot preference rating). Kinetic and kinematic data were collected via motion capture and force plates. Differences between SF and EF were analyzed using paired t tests and Wilcoxon signed-rank tests (α = 0.05). Results Biomechanical results revealed significantly greater anterior-posterior ground reaction force peaks (TFA: +14%, P = 0.028; TTA: +13%, P = 0.046), increased ankle power (All: +21%, P = 0.010) and ankle ROM (all: +14%, P < 0.001). Heel compression increased by 24% ( P = 0.030), indicating enhanced shock absorption. No differences were found in contralateral knee loading. The average 6MWT distance increased by 6% ( P = 0.004). ABC scale and PLUS-M scores revealed no clinically relevant differences. Nine participants (75%, P = 0.021) preferred the SF over their EF. Conclusions The SF demonstrated comparable or superior performance in key biomechanical and functional outcomes. It offers a valuable option for users requiring low build height, increased shock absorption, or terrain adaptability. Clinical Relevance Statement This study highlights the potential of a novel ESR foot design to enhance gait dynamics, comfort, and user satisfaction, especially for transfemoral amputees and individuals with limited clearance needs.