Effects of neck muscle vibration on forearm muscle activity in young adults

The intervention will consist of experimentally induced, high-frequency, low-amplitude mechanical vibration applied to cervical muscles to transiently alter proprioceptive afferent input. Vibration will be delivered using portable mechanical vibration devices affixed to the skin over the right sternocleidomastoid muscle and left cervical extensor muscles using hypafix tape. Participants randomly assigned to the active intervention group will receive mechanical vibration at a frequency of 100 Hz with an amplitude of less than 1 mm for a single continuous period of 10 minutes. The intervention will be delivered once on a single study visit day, and is not personalized, titrated or adapted across participants. All participants receive identical stimulation parameters within their assigned group. The intervention will be delivered face-to-face on an individual basis in a controlled laboratory environment at a university research facility. The vibration will be applied by trained research personnel with experience in neuromuscular and neurophysiological experimental protocols. Intervention fidelity will be ensured by using identical vibration devices and standardized placement procedures across participants. Adherence is ensured by direct supervision of the intervention by research staff and completion of the full 10-minute vibration or sham period is confirmed for all participants.