Vermillion

Researchers are investigating the effects of two types of neck muscle strengthening exercises—isometric (static resistance without joint movement) and isotonic (dynamic movement with resistance)—on exercise-induced hypoalgesia (EIH), which is a reduction in pain after exercise. The study also explores how these exercises affect proprioception, the ability to sense body position in space. Both exercise types are commonly used in physical therapy, but no direct comparisons have been made to determine which might be more beneficial for pain relief and proprioceptive improvement. Participants will perform both exercise types in a crossover design with a 2-3 day gap between sessions. Odd-numbered participants start with isometric exercises followed by isotonic exercises on the second day, while even-numbered participants do the reverse. The isometric protocol involves holding a moderate intensity neck rotation contraction for timed intervals with rest periods, repeated on both sides. The isotonic protocol uses a neck strengthening device with resistance bands to perform controlled neck rotations through a full range of motion at a moderate effort level, also repeated on both sides. Before and after each exercise session, researchers measure pain pressure threshold (PPT) at specific neck muscles using a pressure algometer and assess proprioception through a joint position error (JPE) test involving head movements with a laser pointer. Demographic data such as age, gender, race, and handedness are collected at enrollment. The study spans two testing days per participant with baseline and post-exercise assessments to compare changes in pain sensitivity and proprioception between exercise types.