Fig. 1

Experimental setup. Subjects sit comfortably with their arms supported by a desk. The Electromyography (EMG) signal of a muscle was recorded with bipolar surface electrodes (label 1). EMGs and kinematic data were simultaneously recorded from one tremor-affected arm. Six muscles were: biceps brachii (Biceps), triceps brachii (Triceps), flexor carpi ulnaris (FCU), extensor carpi radialis (ECR), flexor digitorum superficialis (FDS) and extensor digitorum (ED). Arm movement was collected by the motion sensor (label 2) in a magnetic field. Seven degrees of freedom (DOFs) in joints were: wrist flexion/extension (Wr_F), wrist radial/ulnar flexion (Wr_R), forearm pronation/supination (FA_P), elbow flexion/extension (El_F), shoulder flexion/extension (Sh_F), shoulder rotation (Sh_R) and shoulder adduction/abduction (Sh_A). The electrodes of electrical stimulation (label 3) were placed on the dorsal skin of the hand along the distribution of the superficial radial nerve