Feasibility of Combining a Sensorimotor Foot Orthosis With a Prefabricated Carbon-Fiber Ankle-Foot Orthosis: A Pilot Study

BACKGROUND: Stroke, traumatic brain injury, cerebral palsy, and other neuromuscular impairments can result in foot drop, which reduces toe clearance, increases fall risk, and limits mobility. Ankle-foot orthoses (AFOs) are frequently prescribed to address foot drop. Sensorimotor foot orthoses (SMFOs) represent an alternative approach intended to influence muscle activation through sensory stimulation; however, evidence supporting their combined use with AFOs remains limited. OBJECTIVE: To evaluate the feasibility of a subsequent Randomized Controlled Trial (RCT) comparing a prefabricated carbon-fiber AFO worn with and without an SMFO in individuals with neuromuscular or musculoskeletal conditions. METHODOLOGY: A six-month randomized crossover pilot trial was conducted from February to July 2025 at the Department of Rehabilitation Science and Technology, University of Pittsburgh. Three participants with neuromuscular or musculoskeletal conditions were enrolled. The two conditions compared were a prefabricated carbon-fiber AFO (F5 AFO, Thrive Orthopedics, USA) worn alone and the same AFO worn in combination with a custom-made SMFO designed to activate muscles through exteroceptor and proprioceptor stimulation (Springer Aktiv, Germany). The primary outcome was average daily step count measured by a wearable pedometer. Secondary outcomes included gait performance using the Two-Minute Walk Test (2MWT), dynamic balance using the Narrowing Beam Walking Test (NBWT), mobility using the Rivermead Mobility Index (RMI), and device experience assessed via an Ecological Momentary Assessment (EMA) survey. FINDINGS: Three subjects enrolled; one withdrew due to difficulty finding footwear that accommodated the SMFO when worn in combination with the AFO. Two participants completed the study (mean age = 65 years), responded to approximately 77% of EMA prompts, and reported no adverse events. Step count was higher in the SMFO+AFO condition for one participant (1,952 vs. 116 steps) and comparable between conditions for the other (884 vs. 933 steps). Differences on the NBWT and RMI were minimal across conditions; RMI scores were at ceiling for both participants. On the 2MWT, Participant 1 walked 470 m with the AFO alone and 404 m with the combined condition, while Participant 2 walked 303 m and 294 m, respectively. EMA ratings for comfort, function, and satisfaction were higher, and inhibiting effects and wear time were lower with the combined condition throughout the study period. CONCLUSION: The protocol was feasible, safe, and acceptable to participants, with no adverse events and minimal participation burden. These findings support the design of a larger RCT to confirm these preliminary observations. Layman's Abstract Foot drop is a common condition in people who have experienced stroke, traumatic brain injury, cerebral palsy, or other neurological or musculoskeletal conditions. It affects the ability to lift the foot during walking, increasing the risk of tripping and falling. A newer type of insert, called a sensorimotor foot orthosis (SMFO), is designed to influence muscle activity through sensory stimulation. Research on the practicality of combining an SMFO with a standard ankle-foot orthosis (AFO) remains limited. This pilot study looked at whether it would be practical to carry out a larger study comparing an AFO used alone versus an AFO used together with an SMFO. Three participants enrolled in a six-month crossover trial, to try both conditions. Two completed the study (mean age = 65 years); one withdrew due to difficulty finding footwear that accommodated the SMFO when worn in combination with the AFO. The results showed that one participant took more steps when using the combined setup (1,952 vs. 116 steps), while the other participant showed only a small difference between conditions (884 vs. 933 steps). Differences on balance and mobility tests were minimal. On the walking distance test, Participant 1 walked 470 m with the AFO alone and 404 m with the combined condition, while Participant 2 walked 303 m and 294 m, respectively. Participants responded to approximately 77% of daily survey prompts and reported higher ratings of comfort, function, and satisfaction, lower inhibiting effects, and lower wear time, with the combined approach. No safety concerns were observed. The protocol was feasible, safe, and acceptable to participants, with minimal participation burden. The results support conducting a larger study to determine whether combining these devices improves clinical outcomes. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/47162/35016 How To Cite: Aljohani Y, Alamri A, Fiedler G. Feasibility of combining a sensorimotor foot orthosis with a prefabricated carbon-fiber ankle-foot orthosis: A pilot study. Can Prosthet Orthot J. 2026;9(1):8. https://doi.org/10.33137/cpoj.v9i1.47162 Corresponding Author: Yasir Aljohani, PO, MSPO Affiliations: 1) Department of Prosthetics and Orthotics, College of Medical Rehabilitation Sciences, Taibah University, Madinah, Saudi Arabia; 2) Department of Rehabilitation Science and Technology, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, USA.E-Mail: yaa54@pitt.eduORCID ID: https://orcid.org/0000-0002-6603-1526