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



  • 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