The Power of Musification: Sensor‐Based Music Feedback Improves Arm Swing in Parkinson's Disease

BACKGROUND: Reduction of arm swing during gait is an early and common symptom in Parkinson's disease (PD). By using the technology of a mobile phone, acceleration of arm swing can be converted into a closed‐loop musical feedback (musification) to improve gait. OBJECTIVES: To assess arm swing in healthy subjects and the effects of musification on arm swing amplitude and other gait parameters in patients with PD. METHODS: Gait kinematics were analyzed in 30 patients during a 320 m walk in 3 different conditions comprising (1) normal walking; (2) focused swinging of the more affected arm; and (3) with musification of arm swing provided by the iPhone application CuraSwing. The acceleration of arm swing was converted into musical feedback. Arm swing range of motion and further gait kinematics were analyzed. In addition, arm swing in patients was compared to 32 healthy subjects walking at normal, slow, and fast speeds. RESULTS: Musification led to a large and bilateral increase of arm swing range of motion in patients. The increase was greater on the more affected side of the patient (+529.5% compared to baseline). In addition, symmetry of arm swing, sternum rotation, and stride length increased. With musical feedback patients with PD reached arm swing movements within or above the range of healthy subjects. CONCLUSIONS: Musification has an immediate effect on arm swing and other gait kinematics in PD. The results suggest that closed‐loop musical feedback is an effective technique to improve walking in patients with PD.