Orthotic effects of functional electrical stimulation (FES) on gait and dual-task ability in adult patients with upper motor neuron disease

Foot drop is a common impairment of patients with upper motor neuron disease [1]. Besides ankle foot orthoses functional electrical stimulation is used as an alternative treatment to lift the foot (Fig. 1). In comparison, FES shows the advantage of an active ankle dorsiflexion and less ankle joint restrictions while being more comfortable [2]. Even with minor biomechanical improvements, patients satisfaction can be high and superior to AFOs [3]. Fig. 1: Functional electrical stimulation to lift the foot during swing phase.Download : Download high-res image (110KB)Download : Download full-size image For a more targeted orthopedic care in the future, the objective of this study is to gain a deeper understanding of the effects of FES on biomechanics, dual-task ability, proprioception, and patients well-being. A prospective study will be performed on 30 adults with unilateral foot drop of central origin. At the beginning of the treatment (T1) and after twelve weeks (T3), functional and clinical outcomes will be captured. A 3D gait-analysis will be recorded with the FES-device OFF and ON. Relevant data includes kinematics, kinetics, electromyography, strength and spasticity. Additionally, during the twelve weeks (T2), the effects of FES on the patient’s daily-life will be evaluated via ambulatory assessments. Till now, two patients and two controls could be measured for T1. Immediate orthotic effects at T1 (FES OFF vs. FES ON) show an increase in walking speed during normal (3.2%, 2.7%) and dual-task walking (1.0%, 3.1%). Both patients show a decrease in step width in normal (-12.8%, -4.2%) and dual-task walking (-18.1%, -12.9%) and furthermore, both reduce their cognition rate with FES during dual-task walking (-9.7%, -5.9%). With FES, dorsiflexion range in swing could be increased by 3.9° and 1.1°. The effect of dual-task walking increases step width and additional FES then, leads to a decrease again. Early results of minor immediate orthotic effects of FES on foot lift and walking speed match the results of a local pilot study. In dual-task walking without FES, the increase of step width could be the patient’s goal to increase stability. The decrease of step width and the increase of walking speed with additional FES could then therefore be a sign of a more stable gait while doing the additional task with FES. The decrease in cognition rate might be due to the first use of FES and the patients still needed attention on the FES-device and the walking itself which might lead to less capacity for the additional cognitive task. To be able to perform dual-task abilities in daily-life is crucial to interact with the environment sufficiently and therefore decrease chances of falling. Further patients, the long-term comparison as well as the relation to the patient’s well-being during daily-life should show a more detailed understanding of the effects of FES.