We investigated whether vibratory stimulation of the dorsal neck muscles activates fusimotor neurons of lower limb muscles in relaxed human subjects.
Methods: The triceps surae (TS) muscles of seated subjects (n = 15) were conditioned to leave their muscle spindles in either an insensitive (hold-long) or sensitive (hold-short) state. A vibrator (80 HZ) was applied to the dorsal neck muscles for 10 seconds. The tendon jerk was evoked from the right TS immediately before (during) or 5 seconds after (interposed) the offset of vibration.
Results: The size of the reflex after hold-long muscle conditioning and after neck vibration was significantly smaller than the control hold-short reflex (P < 0.001). However, after hold-short conditioning, neck vibration significantly increased tendon jerk amplitude, both during (P = 0.001) and interposed (P = 0.026).
Conclusion: Dorsal neck vibration increases spinal reflex excitability of the TS in relaxed and seated subjects, but not through fusimotor excitation. Muscle Nerve, 2012
Grant Value: $14,970
Chief Investigator: Dr Barbara Polus
Status: Complete
Publications:
- Muscle and Nerve, Volume 45, Issue 3, March 2012, Pages 376 – 384.
Sasaki H and Polus BI (2012) Can neck muscle spindle afferents activate the fusimotor neurons of the limb in the relaxed and seated human? - Chiropractic journal of Australia, Volume 37, Issue 1, March 2007, Pages 30-37.
K, Kumar, DK and Polus BI (2007) The reliability and validity of lumbar paraspinal SEMG during unsupported sitting.
- Chiropractic Journal of Australia, Volume 34, Issue 1, March 2004, Pages 19-22
Walsh MJ, Polus BI, Webb MN. (2004) The role of the cervical spine in balance and risk of falling in the elderly.
- Journal of Neuromusculoskeletal System, Volume 9, Issue 3, September 2001, Pages 82-87
Polus BI and Walsh MJ (2001) “The effect of longitudinal whole body rotation against a steady head on changes in lower motoneuron excitability – a study in humans”
Presentations:
- 5th Interdisciplinary World Congress on Low Back and Pelvic Pain. November 2004. Melbourne, Australia
Kamei K, Kumar DD and Polus BI (2004) The reliability and validity of surface electromyography (SEMG) to study activity patterns of lumbar paraspinal muscles during the execution of simple static postures. - World Federation of Chiropractic’s Biennial Congress, May 2003. Orlando, Florida, USA
Walsh MJ, Polus BI, Webb MN (2003) A pilot study of the association between frequency of positive clinical findings in the cervical spine and clinical measures used to predict the risk of falling in the aged - World Federation of Chiropractic’s Biennial Congress, May 2003. Orlando, Florida, USA
Polus BI, Fernandes K and Walsh MJ (2003) The role of neck proprioceptors in modifying the tonic activation of limb muscles in awake humans - Proceedings of the Australian Physiological and Pharmacological Society, November 2000. Melbourne, Victoria, Australia
Polus BI and Walsh MJ (2000) “The impact of changes in proprioceptive input from the neck on lower limb motoneuron excitability” ” vol 31(2); 109P
Posters:
- Proceedings of the first world congress on Chinese Medicine, November 2003. Beijing, China.
Polus BI Evans BS and Budgell BS (2003) The effect of paraspinal stimulation of the neck on the autonomic regulation of cardiovascular function. p.121 - Proceedings of the Eighth Australian and New Zealand Intelligent Information Systems Conference, December 2003. Sydney, Australia
Ragupathy SC, Kumar DK, Kamei K, Polus BI (2003) Multiple regression and statistical analysis on SEMG of lumbar muscles. PPS 35-40 - Proceedings of the eighth Australian and New Zealand Intelligent Information Systems Conference, December 2003. Sydney, Australia
Djuwari D, Kumar, DK, Ragupathy SC, Polus BI (2003) Multistep independent component analysis for removing ECG artefacts from back SEMG signals.pps 439-444