Feedforward activity of the cervical flexor muscles during voluntary arm movements is delayed in chronic neck pain
- 1.7k Downloads
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.
KeywordsNeck muscle Electromyography Neck pain Postural control
This study was supported by a University of Queensland Small Grant and grants received from the Centre of National Research on Disability and Rehabilitation Medicine (CONROD; Australia) and Suncorp Metway General Insurance. Paul Hodges was supported by the NHMRC of Australia.
- Bouisset S, Zattara M (1981) A sequence of postural adjustments precedes voluntary movement. Neurosci Lett 22:263–270Google Scholar
- Falla D, Jull G, Hodges P (2004a) Neck pain patients demonstrate reduced activation of the deep neck flexor muscles during performance of the cranio-cervical flexion test. Spine (in press)Google Scholar
- Falla D, Rainoldi A, Merletti R, Jull G (2004b) Spatio-temporal evaluation of neck muscle activation during postural perturbations. J Electromyogr Kinesiol (in press)Google Scholar
- Hodges PW, Richardson CA (1997b) Relationship between limb movement speed and associated contraction of the trunk muscles. Ergonomics 40:1220–1230Google Scholar
- Jull GA (2000) Deep cervical flexor muscle dysfunction in whiplash. J Musculoskel Pain 8:143–154Google Scholar
- Lang J (1993) Clinical anatomy of the cervical spine. Thieme Medical, New YorkGoogle Scholar
- Nannucci L, Merlo A, Merletti R, Rainoldi A, Bergamo R, Melchiorri G, Lucchetti D, Caruso I, Falla D, Jull G (2002) Atlas of the innervation zones of upper and lower extremity muscles. In: Proceedings of XIV Congress of the International Society of Electrophysiology and Kinesiology, Vienna, pp 353–354Google Scholar
- Winters JM, Peles JD (1990) Neck muscle activity and 3D head kinematics during quasistatic and dynamic tracking movements. In: Winters JM, Woo SL-Y (eds) Multiple muscle systems: biomechanics and movement organisation. Springer-Verlag, Berlin Heidelberg New York, pp 461–480Google Scholar