University of Queensland physiotherapists have proved that manual therapy triggers pain relief mechanisms controlled by the nervous system.
They say their research is a breakthrough in understanding manual therapy and its involvement in the management of musculoskeletal problems.
Results dismiss the accepted theory that manual therapy only treats the joints or peripheral structures of the body to relieve pain.
Manual therapy involves using the hands to mobilise or manipulate joints or other structures to produce a desired movement or therapeutic effect in part of the body.
The study, led by Dr Tony Wright of the Physiotherapy Department, used tennis elbow as a model to understand manual therapy.
Team members include lecturer Bill Vicenzino, former masters student Josephine Smith and PhD student Tina Souvlis, all from the Physiotherapy Department.
'The nervous system has its own mechanisms for controlling pain and we have evidence that manual therapy techniques can activate those mechanisms,' Dr Wright said.
He said manual therapy could produce pain relief within minutes. For example, positive results were produced after three 30 second sets of mobilising the neck to treat tennis elbow.
Manual therapy was generally risk free, except for patients with osteoporosis, and when applying manipulation to the upper part of the spine, he said.
The treatment has evolved over thousands of years across several cultures and has become widely used and studied by physiotherapists in the past 30 years.
'Despite its long history we haven't understood how it worked. It was thought the treatment worked on the joints but now we know it influences the nervous system,' Dr Wright said.
The researchers surveyed more than 50 adults who had tennis elbow pain for more than six weeks.
Tennis elbow, or lateral epicondylitis, results from excessive strain on the forearm extensor muscles and tendons attached to the outside point of the elbow. Those affected include keyboard users, tennis players, golfers and those who engage in repetitive tasks.
Researchers found that about one quarter of those with tennis elbow pain surveyed were very sensitive to cold stimulation.
'This usually indicates some involvement of the sympathetic nervous system which controls the blood vessels and blood supply to muscles and skin,' Dr Wright said.
'There may be some abnormality in the sensitivity of blood vessels to the chemicals released by the nerves or some alteration in the way the nervous system functions.
'This could affect the function of the muscles and increase the likelihood of pain.'
In collaboration with Dr Jim O'Callaghan, senior visiting medical officer of the Royal Brisbane Hospital Pain Clinic, the team tested the drug Guanethidine, generally used for patients with severe pain.
'The drug effectively blocks the activity of the sympathetic nervous system and our study demonstrated that it selectively reverses the sensitivity to cold stimulation. It may be a potential treatment for tennis elbow pain in those with cold sensitivity,' Dr Wright said.
For more information, contact Dr Wright (telephone 07 3365 2779).
