When we try and help to fix the underlying causes of your aches and pains or other symptoms, we often find imbalances in your muscle strength. These weakness patterns seem to contribute to patterns of tension in the joints and muscles or areas of instability and injury, which both can contribute to your feeling of pain. Your muscles are switched on by your nerves and each nerve going to one of your muscles has at least 19 different kinds of inputs acting to either turn on or turn off your muscles. One of these inputs is from the organs in your body.
The question is why do some of your muscles sometimes seem to go weak in response to a problem with one of your internal organs? What pathways exist which might contribute to these muscles usually weakening in pairs?
Take for example the extreme case of someone suffering from early stage acute appendicitis. Pain signals from the appendix and enter into the T10 segment of the spinal cord. Connections with Autonomic Tract Fibres convey information to organ control areas in the brainstem, which is relayed to a part of the brain called the hypothalamus and to areas involved in emotion and motivation system. Stimulation of the nociceptive tract related to the appendix often results in referred pain to the umbilical region. This happens because the T10 area of the spinal cord receives sensory information from the skin, organs such as the appendix and various skeletal muscles. Due to this convergence of wiring the brain may misinterpret the discomfort as arising from skeletal muscle. Part of the automatic nervous system controlling the gut function acts to slow down the flow of the gut and also constrict blood vessels. The pain sensing nerves cause a reflex contraction of the muscles related to that segment (the abdominal muscles).
We can postulate a similar set of events occurring in the less severe event of visceral muscle contraction stimulating the nociceptive tracts. Why might particular muscle weakness patterns occur in relation to visceral dysfunction? The triggering of somatic efferents will cause contraction of related muscles. Muscles that are receiving too little activation or too much activation cannot do work so may appear weak on manual testing. Related muscles (synergists etc.) will be activated by Renshaw Cell bias. Alternatively the antagonist muscle may be involved through Reciprocal Inhibition. Agonist, antagonist, synergist and reactive muscle groups may help explain some of the more bizarre organ-somatic muscle weakness relationships.
What mechanisms might contribute to muscle weaknesses related to visceral issues occurring bilaterally? The current most probable plausible pathway is through the higher brain centres. As well as convergence in the spinal cord, the somatosensory and parietal cortices, thalamus, basal ganglia, and cerebellum, are activated by both visceral and cutaneous painful stimuli. The spinothalamic, spinoreticular, and spinomesencephalic tracts all contain neurons that respond to both somatic and visceral stimuli. Visceral but not cutaneous pain activates bilaterally the inferior primary somatosensory cortex, bilateral primary motor cortex, and a more anterior locus within anterior cingulate cortex. Multifocal and bilateral cerebellar activation has also been evoked by visceral and cutaneous pain.
Whether you are experiencing back pain, neck pain, headaches, joint aches and pains, aches and pains in your muscles, arm pain (shoulder pain, elbow pain, wrist pain, hand pain) and leg pain (hip pain, knee pain, ankle pain, foot pain); the Preston Chiropractor and Preston Massage Team at Back-in-Action can help you find pain relief and root out the underlying causes contributing to your problem.
From the Preston Chiropractor Team
Getting You Back in Action & Enjoying Your Life Again
Serving the people of Preston and surrounding areas including Southport and Lytham St Annes