This dataset includes the source data (csv table) for figures 4 and 5 published at the paper. They describe the response time and onset latencies of 8 trunk, neck, and shoulder muscles for 33 healthy subjects performing an arm reaching task requiring trunk flexion.

The EMG activity was recorded from 8 muscles on the left side of the body: sternocleidomastoid (SCM), middle deltoid (DEL), trapezius (TRA), pectoralis major (PECT), upper abdominal Th6 (ABD), and paraspinal muscles at cervical C3 (PC), thoracic T6 (PT), and lumbar L2 (PL) levels. Disposable adhesive surface electrodes (outer diameter 20 mm; Technomed) were attached over the muscle belly, and the EMG signals were collected using a ten-channel EMG system (Synergy, VIASYS Healthcare UK Ltd., 2005) at a sampling rate of 10 kHz. The ground electrode was placed on the left forearm. In addition, the artifact coming from the wired switch button was recorded with the same equipment, and this signal was used to calculated the response time, i.e., the time to complete the task (until button press). The study was conducted at the Institut Guttmann, Badalona, Spain. The protocol was approved by the Ethics Committee of the Institut Guttmann, and written informed consent was obtained from all the participants prior to the experiment. Research was carried out in accordance with the standards of the Declaration of Helsinki. During the experiments, subjects were sitting in a wheelchair facing a wall. The subjects’ task consisted of raising the left arm and, by tilting the trunk forward, press a switch button attached to the wall and return to their initial position as fast as possible. The switch was centred on the subject’s midline and the distance between the switch and the subject’s index fingertip when the left arm was fully extended horizontally was either 15 cm or 30 cm. Each participant repeated the same manoeuvre 20 times at each distance (15 and 30 cm). In five randomly selected trials, a startling auditory stimulus (SAS) was presented. Therefore, we had two different conditions: startling auditory stimulus (‘SAS’, 5 trials per subject), and baseline movement (‘non-SAS’, 15 trials per subject). The values reported in the dataset are the mean values per subject for each distance and condition.