Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 14

J Rehabil Med 2019; 51: 11–17 ORIGINAL REPORT EFFECT OF LONG-TERM USE OF ANKLE-FOOT ORTHOSES ON TIBIALIS ANTERIOR MUSCLE ELECTROMYOGRAPHY IN PATIENTS WITH SUB-ACUTE STROKE: A RANDOMIZED CONTROLLED TRIAL Corien NIKAMP, MSc 1,2 , Jaap BUURKE, PhD, PT 1,3 , Leendert SCHAAKE, BSc 1 , Job VAN DER PALEN, PhD 4,5 , Johan RIETMAN, PhD, MD 1,2,6 and Hermie HERMENS, PhD 1,3 From the 1 Roessingh Research and Development, 2 Department of Biomechanical Engineering, TechMed Centre, University of Twente 3 Department of Biomedical Signals and Systems, TechMed Centre, University of Twente, 4 Medisch Spectrum Twente, Medical School Twente, 5 Department of Research Methodology, Measurement and Data Analysis, University of Twente, and 6 Roessingh Center for Rehabilitation, Enschede, The Netherlands Objective: To determine: (i) whether the use of ank- le-foot orthoses over a period of 26 weeks affects tibialis anterior muscle activity; (ii) whether the ti- ming of provision of ankle-foot orthoses (early or delayed) affects the results; (iii) whether the pro- vision of ankle-foot orthoses affects tibialis anterior muscle activity within a single measurement. Design: Randomized controlled trial. Subjects: Unilateral hemiparetic subjects, a maxi- mum of 6 weeks post-stroke. Methods: Subjects were assigned randomly to early (at inclusion; week 1) or delayed provision of ankle- foot orthoses (8 weeks later; week 9). Tibialis anteri- or electromyography was measured with and without ankle-foot orthoses, in study weeks 1, 9, 17 and 26. Results: A total of 26 subjects were analysed. In a single measurement, use of an ankle-foot orthosis significantly reduced the activity levels of the tibialis anterior muscle during the swing phase (p  = 0.041) compared with walking without an ankle-foot or­ thosis. During the 26-week follow-up, no changes were found in tibialis anterior muscle activity in the swing phase without an ankle-foot orthosis, both within-groups (p  = 0.420 early; p  = 0.282 delayed), and between-groups (p  = 0.987). After 26 weeks, no differences were found in tibialis anterior mus- cle activity between both groups in the swing pha- se, with (p  = 0.207) or without ankle-foot orthoses (p  = 0.310). Conclusion: Use of ankle-foot orthoses post-stroke reduced tibialis anterior muscle activity in the swing phase within one measurement; however, long-term use of ankle-foot orthoses for 26 weeks did not af- fect such activity. Early or delayed provision of ank- le-foot orthoses did not affect the findings. The re- sults indicate that there is no need to fear negative consequences on tibialis anterior-activity because of long-term AFO-use (early) after stroke. Key words: ankle-foot orthosis; stroke rehabilitation; muscle electromyography; tibialis anterior; long-term effects; timing of provision; randomized controlled trial. Accepted Sep 22, 2018; Epub ahead of print Oct 26, 2018 J Rehabil Med 2019; 51: 11–17 Correspondence address: Corien Nikamp, Roessingh Research and Development, Roessinghsbleekweg 33b, NL-7522 AH Enschede, The Netherlands. E-mail: [email protected] LAY ABSTRACT Ankle-foot orthoses (AFOs) are often used to improve walking after stroke. However, it is unknown whether early or later provision of AFOs affects muscle activity, and what are the effects of long-term AFO use after stroke. Some clinicians fear that early use of AFO af- ter stroke has negative effects on muscles around the ankle. Therefore, we studied the effect of AFO use on the tibialis anterior muscle in 26 subjects after stroke. Subjects were prescribed an AFO in week 1 of the study, or 8 weeks later. Muscle activity was measured 4 ti- mes over a period of 26 weeks. We found that AFO use reduced muscle activity levels compared with walking without an AFO within 1 measurement. However, long- term use of an AFO for a period of 26 weeks did not affect muscle activity. These effects were the same for the subjects provided with the AFO in week 1 or 8 weeks later. This study did not find any negative effects on ac- tivity of the tibialis anterior muscle with long-term use of an AFO early after stroke. W alking function is often impaired after stroke (1). Insufficient foot-clearance during the swing phase is an important alteration contributing to limited walking function post-stroke. Activity of the tibialis anterior (TA) muscle is important for foot-clearance. In healthy subjects, the TA becomes active just before foot-off in order to lift the foot during the swing phase, peaking during early swing (2). A second burst of acti- vity controls pre-positioning before initial contact and controls plantarflexion during the loading response. Ankle-foot orthoses (AFOs) are often provided post- stroke to improve foot-clearance in swing (3), although the optimal timing of provision after stroke is unclear (4). Some clinicians are reluctant to prescribe AFOs post-stroke as they fear AFOs may result in disuse of muscles, in particular the TA muscle (3, 5, 6). Several studies compared walking with and without AFOs (5–9). Within a single session a decrease in electro- myography (EMG) of the TA muscle was found during walking with AFOs (5–8). Only one study included a follow-up period (8). Geboers et al. (8) found im- mediate reduced activity of the ankle dorsiflexors of 7% in patients with peripheral paresis, calculated over the whole step cycle. Six weeks of AFO use, however, This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977 doi: 10.2340/16501977-2498