Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain

• Published in: Experimental brain research Vol. 157; no. 1; pp. 43 - 48
• Main Authors: Falla, D., Jull, G., Hodges, P. W.
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.07.2004; Springer Nature B.V
• Subjects: Adult; Arm - innervation; Arm - physiology; Biological and medical sciences; Cervical Vertebrae - innervation; Cervical Vertebrae - physiology; Chronic Disease; Electromyography - statistics & numerical data; Feedback - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Middle Aged; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Movement - physiology; Muscle Contraction - physiology; Neck Muscles - innervation; Neck Muscles - physiopathology; Neck Pain - physiopathology; Posture - physiology; Proprioception - physiology; Reaction Time - physiology; Reflex - physiology; Vertebrates: nervous system and sense organs; Zygapophyseal Joint - innervation; Zygapophyseal Joint - physiology; Human; Force; Electrophysiology; Scalenus muscle; Striated muscle; Joint; Voluntary movement; Motor control; Osteoarticular system; Neck pain; Pain; Postural control; Body movement; Sternocleidomastoid muscle; Flexor muscle; Neck muscle; Electromyography; Neck; Feedforward; Cervical spine
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-003-1814-9

The objective of this study was to compare onset of deep and superficial cervical flexor muscle activity during rapid, unilateral arm movements between ten patients with chronic neck pain and 12 control subjects. Deep cervical flexor (DCF) electromyographic activity (EMG) was recorded with custom electrodes inserted via the nose and fixed by suction to the posterior mucosa of the oropharynx. Surface electrodes were placed over the sternocleidomastoid (SCM) and anterior scalene (AS) muscles. While standing, subjects flexed and extended the right arm in response to a visual stimulus. For the control group, activation of DCF, SCM and AS muscles occurred less than 50 ms after the onset of deltoid activity, which is consistent with feedforward control of the neck during arm flexion and extension. When subjects with a history of neck pain flexed the arm, the onsets of DCF and contralateral SCM and AS muscles were significantly delayed ( p<0.05). It is concluded that the delay in neck muscle activity associated with movement of the arm in patients with neck pain indicates a significant deficit in the automatic feedforward control of the cervical spine. As the deep cervical muscles are fundamentally important for support of the cervical lordosis and the cervical joints, change in the feedforward response may leave the cervical spine vulnerable to reactive forces from arm movement.