A pilot study of a crossover trial with randomized use of ankle-foot orthoses for people with Charcot–Marie–Tooth disease

OBJECTIVES: This was a pilot and feasibility study of a crossover trial with randomized use of ankle-foot orthoses by people with Charcot-Marie-tooth (CMT) disease, investigating the effects of these on gait parameters, practical aspects of use and achievement of goals. DESIGN: A randomized crossover trial. SETTING: The community and ambulatory care. PARTICIPANTS: Eight adults with CMT disease type 1 or 2. INTERVENTIONS: Ligaflex™, custom-made polypropylene and silicone ankle-foot orthoses worn in randomized order for three weeks each, with a washout week in-between; the orthoses of each participant's choice were then worn until 28 weeks. MAIN OUTCOME MEASURES: The primary outcome measure was gait velocity; other outcome measures included Goal Attainment Scaling; Likert scores, concerning aspects of orthosis use and gait analysis parameters. RESULTS: Gait velocity was greatest wearing polypropylene orthoses, median 0.96 (interquartile range (IQR) 0.75-1.18) ms(-1), compared with silicone orthoses, median 0.88 (0.71-1.12) ms(-1), and no orthosis, median 0.79 (0.56-0.84) ms(-1), P=0.006. The silicone orthoses met goals more successfully and scored more favourably for comfort, 5.0 (5.0-6.0), P=0.003 and pain, 5.5 (4.0-7.0), P=0.015. Future modifications to study methodology were identified, such as a longer period of wear and measurement of walking in different situations. CONCLUSIONS: This study confirmed the feasibility of a larger trial. It indicated differences in walking velocity and parameters concerning wear of the orthoses that could be explored further. A further crossover trial would require 27 participants in order to show a clinically meaningful difference in velocity of 0.13 ms(-1) with 90% power and alpha of 5%.