Mechanisms for chronic muscular pain
Research project
Contact persons: Ann L. Persson; Bengt H. Sjölund
The pathophysiological mechanisms of chronic muscle pain are only
partially understood. Injury, inflammation and changes in muscle
blood flow causing peripheral sensitization of nociceptors and
hyperreflexia are possible precipitating factors. Alterations of
oxidative metabolism and capillarisation in some muscle fibres are
associated with the presence of tender points. In addition,
bilateral increases of Pressure Pain Thresholds after strenuous
muscle activity indicate that the involvement of a central pain
regulating mechanism is important for sensory function both in
healthy humans and in persons with musculoskeletal pain (1), such
as torture victims.
A model of muscle pain from blunt repeated minimal trauma is under
development (2).
In a recent analysis of women with chronic trapezius myalgia (3),
we found three clusters of different properties, highlighting the
multifactorial mechanisms responsible.
1. Persson AL, Hansson G-Å, Kalliomäki J, Sjölund BH. Increases in
local pressure pain thresholds after muscle exertion in women with
chronic shoulder pain. Archives of Physical Medicine and
Rehabilitation 2003;84:1515-1522.
2. Sjölund BH, Persson AL. Pressure pain threshold changes after
repeated mechano-nociceptive stimulation of the trapezius muscle:
possible influence of previous pain experience. Journal of Pain
2007;8:355-62.
3. Persson AL, Sjölund BH, Larsson B. Three clusters of different
properties characterize women with chronic trapezius myalgia.
Journal of Musculoskeletal Pain 2008;16:289-299.