Feasibility of combining a sensorimotor foot orthosis with a prefabricated carbon-fiber ankle-foot orthosis: A pilot study.

backgroundStroke, 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.

objectiveTo 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.

findingsThree 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.

conclusionThe 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.