Intensive Conventional Rehabilitation for Reducing Upper Limb Co-contraction and Functional Improvement in Parkinson’s Disease: A Case Report

Upper limb dysfunction significantly impairs activities of daily living in patients with Parkinson's disease (PD). This dysfunction is partially attributable to abnormal muscle contraction. Although robot-assisted therapy improves upper limb function in patients with PD, these devices are expensive and not easily accessible in standard rehabilitation facilities. Non-robotic interventions, such as repetitive large-amplitude movements, improve upper-limb performance; however, whether these conventional exercises could improve co-contraction remains unclear. Herein, we present the case of a 70-year-old man with PD (Hoehn and Yahr Scale, stage 2) who presented with bradykinesia and difficulty moving his right arm. He underwent a two-week intensive rehabilitation program (1 h per day for five days a week) focusing on upper limb training. Following the intervention, the nine-hole peg test times and mean co-contraction index during reaching showed clinically significant improvements in both upper limbs, exceeding the minimal detectable change. This functional recovery was accompanied by a physiological reduction in muscle co-contraction. These results suggest that intensive conventional rehabilitation could be an effective and accessible alternative to robotic therapy for modulating muscle tone.