Weak muscle neurophysiology and chiropractic care

A registered chiropractor with at least five years of clinical experience will assess the cervical spine for vertebral dysfunction with the participant either standing or seated on a chiropractic table. The clinical indicators used to assess spinal function before spinal adjustment include evaluating joint tenderness to palpation, manually palpating for a restricted intersegmental range of motion, assessing for palpable asymmetric intervertebral muscle tension, and checking for any abnormal or restricted joint play and end-feel of the joints. Chiropractors use these biomechanical characteristics as clinical indicators of spinal dysfunction and vertebral subluxation. All spinal adjustments in this study will involve high-velocity, low-amplitude thrusts to the cervical spine, a standard adjusting technique used by chiropractors. This will be delivered while the participant is lying flat on their back on a chiropractic table. The mechanical properties of chiropractic adjustment have been investigated, and although the actual force applied depends on the chiropractor, the patient, and the spinal location of the subluxation, the general shape of the force-time history of spinal adjustments is very consistent, with the duration of the thrust always being less than 200 milliseconds. This type of adjustment has been specifically chosen because previous research has shown that reflex electromyographic activation observed after adjustments only occurred following high-velocity, low-amplitude adjustments, as opposed to lower-velocity mobilizations. This adjustment technique has also been used in studies investigating the neurophysiological effects of spinal adjustment. The neck assessment and chiropractic adjustment, which may take around 15 minutes in total, will be conducted in a single session.