Abstract

Background: Plantar fasciitis (PF) is a prevalent foot condition significantly impacting daily functioning. While customized foot orthoses (CFOs) are commonly recommended, limited objective research exists on their neuromuscular effects during gait. This first study investigates and directly compares the immediate effects of different CFO designs on lower-extremity muscle activity and gait parameters during stance in PF patients.
Methods: Forty-five participants with PF underwent gait analysis under four conditions: shod, CFOs without wedge, CFO W1 (dual rearfoot and forefoot posting), and CFO W2 (forefoot posting). Spatiotemporal gait parameters and lower-extremity muscle activity were assessed using an instrumented walkway and wireless electromyography (EMG). Comfort scores were reported at the end of each condition.
Results: Exploratory post-hoc analysis, based on the unadjusted result, indicated that all CFO conditions significantly increased comfort scores compared to shod conditions (p < 0.001). The CFO W1 notably increased stance phase duration (p < 0.05) and prolonged double support phase (p < 0.001). The CFO W1 design increased tibialis anterior (TA) activity and reduced biceps femoris (BF) activation compared to CFO W2 (both p < 0.05), indicating selective, limited changes in TA and BF peak activity.
Conclusion: Different CFO designs produced distinct immediate biomechanical modifications. The CFO W1 may reflect a more cautious gait pattern or altered temporal coordination, accompanied by selective changes in peak neuromuscular activity. While these results underscore the potential value of considering not just pain reduction but also specific functional biomechanical responses, clinical recommendations for individualized orthotic prescription require longitudinal evidence.