Example segment (~100 s, loaded movements) of data recorded in one participant. (A) Hand trajectory (X-axis: medial/lateral; Y-axis: anterior/posterior; Z-axis: superior/inferior relative to shoulder). (B) Grip force and rectified and smoothed EMG signals from 12 muscles (abbreviations as used in Figure 1). Vertical dashed line indicates time at which subject grasped the load (1000 g). Scale bars for EMG signals represent muscle activation normalized to that recorded during a maximum voluntary contraction for each muscle.