So how does massage reduce pain? – Part 1
I said in a previous post that scientists are interested in finding out how massage works. So if we accept that massage reduces muscle pain, that leaves the question, “How does massage reduce muscle pain?”.
In 1965, Ronald Melzack and Patrick Wall outlined a scientific theory about psychological influence on pain perception; the ‘gate control theory’. According to the gate control theory, pain signals are not free to reach the brain as soon as they are generated at the injured tissues or sites. They need to encounter certain ‘neurological gates’ at the spinal cord level and these gates determine whether the pain signals should reach the brain or not. In other words, pain is perceived when the gate gives way to the pain signals and it is less intense or not at all perceived when the gate closes for the signals to pass through.
Cutaneous mechano-receptors are stimulated by touch (massage) and transmit information within large never fibres to the spinal cord. These impulses block the passage of painful stimuli entering the same spinal segment along small, slowly conducting neurons.
This theory gives the explanation for why someone finds relief by rubbing or massaging an injured or a painful area. For example, the pain gate theory explains “how” a child feels better after mum or dad intuitively rub their knee when they have fallen over.
In summary massage produces short term pain relief by being a particularly effective trigger for the pain gate process.
References
Melzack R, & Wall PD (1965). Pain mechanisms: a new theory. Science (New York, N.Y.), 150 (3699), 971-9
Moayedi M, & Davis KD (2013). Theories of pain: from specificity to gate control. Journal of neurophysiology, 109 (1), 5-12
Jacobs M. (1960) Massage for the relief of pain: anatomical and physiological considerations. Physical Therapy Review, 40: 93-8
Melzack R, Wall PD. Pain mechanisms: a new theory. Science. 1965 Nov 19;150(3699):971–979.
Wells PE, Frampton V, Bowsher D. (1988) Pain: Management and Control in Physiotherapy. Heinemann Medical. Chapter 13.
Watson J. (1982) Pain mechanisms: a review. 1. Characteristics of the peripheral receptors. Australian Journal of Physiotherapy. 27:135-43
Related Posts
Reflexology and Pain Management – Part 3
In previous posts in this series I have discussed the nature of pain, and how is evidence for the reflexology can be used for acute pain. In this article I want to discuss reflexology and chronic pain, as back pain is the most common chronic pain and it effects 8 out of 10 people in their lifetime, I will focus on studies that have looked at chronic lower back pain. An initial pilot study was carried out entitle Reflexology in the management of low back pain: a pilot randomised controlled trial by F Quinn, CM Hughes and GD Baxter. the results of which was published (see Complement Ther Med. 2008 Feb;16(1):3-8. doi: 10.1016/j.ctim.2007.05.001. Epub 2007 Jun 27.) Participants suffering from non-specific lower back pain were recurited and randomly assigned to a reflexology or sham group. Each patient received either a 40 minute reflexology treatment or a sham treatment according to which group they were in once per week for 6 consecutive weeks. The key measure of success was the measurement of pain on the visual analogue scale supplemented by the McGill pain questionnaire, Roland-Morris disability questionnaire, and SF-36 health survey. Outcome measures were performed at baseline, week 6, week 12 and week 18. The results incidicated that reflexology may have a positive effect on Lower Back Pain. This initial trail was followed up by a more comprehensive study of times were nurses were the patients, nursing is in the top ten professions for high incidence of lower back pain. Again this study was a double bind trial, and the same measurements of pain were used as in the trail. The study recruited 50 male and 50 female nurses with chronic lower back pain to take part in the trail. 40 minute sessions of reflexology or sham treatements were performed three times a week for two weeks. The study concluded Reflexology can be effective in reducing the severity of chronic back pain, i.e. it is able to reduce pain from moderate to mild. (see The Irainian Journal of Nursing Times (reference Iran J Nurs Midwifery Res. 2012 Mar-Apr; 17(3): 239–243.), focused on back pain in nurses) In conclusion it is clear that while the number and size of the studies are small there is a clear trend which demonstrates the effectiveness of Reflexology in helping to reduce pain levels especially in cases of lower back pain. Remember I offer a 15 minute taster Reflexology session for anyone who would like to try reflexology.
Are acupressure points the same as trigger points?
In last week's article entitled Why do your muscles hurt? I explained what trigger points were. In this article I want to explain the difference between acupressure points and trigger points. Acupressure points (are the same points used by Acupuncturists) are situated on the meridians. With acupressure they are stimulated by the application of pressure from the fingers & elbows to relieve
- pain
- muscular tension
- headaches
What happens to your muscles when you sit?
Chair sitting is unique in that Gluteus maximi are totally relaxed at the same time as having an upright torso, and they are therefore not able to contribute to lumbar extension and back stabilization as they usually do. Without the help of the Gluteal muscles, the Erector Spinae muscles above become tired and painful in a very short time, and give up fighting to maintain the correct "hollow" in the lumbar spine.
The diagram on the left indicates what happens to three key muscles when you spend long periods of time sitting.
The Hamstrings (H) are shortened by sitting. Also, during sitting, the Gluteus Maximus (GM) is relaxed and unable to tension the lumbosacral fascia. This means the Errector Spinae (ES) muscle group must therefore perform the entire lumber extension workload.
This article discusses the link between lower back pain and the following muscle problems:-
- Shortening of the hamstring muscle.
- Overworking of the Erector Spinae muscle group and the development of trigger points.
- Overworking of the Iliopsoas muscle group and the development of trigger points.
- Diffuse achy - type pain radiating out from the groin area to the lower back, and possibly around to the side of the hip and the butt area. If the trigger points in the groin are not pressed, the pain is not sharp or stabbing.
- Relief of pain is often experienced by sitting down.
- Worse upon lengthening the iliopsoas, i.e. when one stands up, or straightens the hip joint.
- Worse for doing situps.
- Worsened by externally rotating the hip (i.e. making the knee cap look outward) when the hip joint is fully extended.
- In patients with sciatic nerve pain, lying flat on one's back with the legs out straight causes the trigger point tightened iliopsoas to compress the lumbar vertebrae together, with the result that the nerve roots of the sciatic nerve are compressed too.
- When lying flat on one's back, doing a straight leg raise reveals weakness on the affected side.
- In patients with sciatic nerve pain due to nerve root compression, lying flat on one's back with legs out straight stretches that trigger point tightened iliopsoas. The result is that the iliopsoas compresses the lumbar vertebrae together, and the the nerve roots of the sciatic nerve are compressed at the same time.
