By Laura Fonda Hochnadel
Foot drop is a common presentation in people who have multiple sclerosis (MS). The inability to lift the forefoot off the ground adequately, such as to clear curbs and stairs, affects gait and increases fall risk. Ankle–foot orthoses (AFOs) and functional electrical stimulation (FES) are both used to treat foot drop. While AFO use is considered the usual form of treatment, a team of researchers from the United Kingdom found no previous studies comparing the effectiveness of the 2 devices in MS patients. Thus, they sought to compare the clinical and cost effectiveness of AFO and FES use over 12 months in this patient population.
Eighty-five people were randomly assigned to receive either an AFO or FES device; none had previously received either treatment. AFO prescription was based on recommendations made by the Best Practice Statement for AFO following stroke because no recommendations currently exist for AFO prescription in MS. The FES device used was the Odstock Dropped Foot Stimulator (ODFS) Pace.
Nine outcome measures were assessed, along with equipment and staff time costs of both interventions, at baseline and at 3, 6, and 12 months. Testing included 3 performance outcome measures and 5 patient-reported outcome measures (PROMs): the 5-minute self-selected walk test (primary), Timed 25 Foot Walk, oxygen cost of walking, Multiple Sclerosis Impact Scale-29, Multiple Sclerosis Walking Scale-12, Modified Fatigue Impact Scale, Euroqol 5-dimension 5-level questionnaire, Activities-specific Balance and Confidence Scale, and Psychological Impact of Assistive Devices Score (PIADS).
Regarding the performance-related outcome measures, the researchers noted that both groups walked faster with their device in the walking speed tests, although there were no significant differences between the groups at 12 months. Furthermore, although there was a significant change in oxygen cost over the 12 months, the groups also performed similarly in this measure. The FES group did, however, demonstrate a clinically significant ongoing orthotic effect for both walk tests, whereas the AFO group did not. These clinically significant effects are defined as ≥0.5m/s increase in walking speed.
The only difference between the groups’ PROMs was noted in the PIADS, which was administered at 12 months only. The FES group scored significantly higher for the competence, adaptability, and self-esteem subscales, which may be due to patients viewing FES as a more acceptable treatment. The study authors further speculated that this might explain the greater attrition rate among the AFO group over the 12 months and result in better device compliance with FES. The research team also found FES to be a cost-effective treatment for foot drop in MS and, despite its higher initial cost, noted that it offers a viable economic alternative to AFO.
The authors conclude that in all aspects examined—clinical measures, patient-reported outcome measures, and financial analysis—FES and AFOs have comparable positive effects and both should be considered as feasible treatment protocols in MS patients with foot drop.
Source: Renfrew LM, Paul L, McFadyen A, et al. The clinical- and cost-effectiveness of functional electrical stimulation and ankle-foot orthoses for foot drop in Multiple Sclerosis: a multicentre randomized trial. Clin Rehabil. 2019:33(7):1150-1162.