The effects of a cervical mobilisation technique on sympathetic outflow to the upper limb in normal subjects

Manipulative therapy techniques are commonly used by physiotherapists in the management of spinal pain syndromes. Although manipulative therapy is widely adopted, the mechanisms by which it exerts its analgesic effects and the physiological effects it produces are poorly understood and inadequately researched. The aim of this study was to evaluate the effect of a commonly utilised cervical mobilisation technique on sympathetic function in the upper limb of normal, pain-free volunteers. The manipulative therapy technique produced a significantly greater increase in skin conductance (SC) than either the placebo or control conditions during the treatment period and the subsequent monitoring period. Central vertebral pressure also produced a reduction in skin temperature, although this effect was of lesser magnitude than the change in SC.The results of this study indicate that a grade III central vertebral pressure technique applied to C5 causes increased sympathetic efferent activity in the upper limb. This finding is important because it provides objective evidence to indicate that manipulative therapy techniques are capable of exerting physiological effects in normal, pain-free individuals and also because it has implications for further investigations of the neurophysiological mechanisms underlying manipulation-induced analgesia (MIA).