Tuesday 6th February 2018

The presence and treatment of myofascial trigger points in chronic shoulder pain

Summary

The authors of two pieces of research state that although myofascial trigger points (MTPs) are well accepted as a source of pain they are barely considered when  diagnosing or treating shoulder pain.  To investigate their involvement the researchers first examined the shoulder muscles of 72 subjects with chronic non-specific shoulder pain, finding a high prevalence of MTPs.  They then conducted a randomised control trial where the treatment group received 12 weekly sessions each consisting of multiple forms of trigger point therapy.  After the 12 weeks the number of trigger points, plus pain and disability scores had reduced to about half. There was no indication of whether these effects lasted after treatment stopped.

From this we can conclude that MTPs are heavily involved in non-specific shoulder pain, and their treatment is a must.  However, as 12 extended weekly sessions produced only what could be described as “temporarily half fixed”, treatment of MTPs using professional therapists alone may be so expensive and time consuming as to be unpractical.   We investigate a solution to supplement professional care making it practical and affordable to treat this major cause of pain.

Introduction

Two pieces of research by C Bron et.al. point the way to successfully treating shoulder and other musculoskeletal pain syndromes.  The first investigates the prevalence of myofascial trigger points (MTPs) in patients with chronic shoulder pain.  The second is a trial investigating the treatment of these.
In their discussion of previous research the authors state that according to medical literature the most common cause of shoulder pain is subacromial impingement, which causes inflammation and degeneration of the subacromial bursae and tendons.  This is believed in spite of the following facts.

  • Calcifications, acromion spurs, subacromail fluid and signs of tendon degeneration are equally prevalent in healthy subjects as in patients with shoulder pain.
  • Scientific evidence from randomised controlled trials (RCTs) and systemic reviews of the effectiveness of multimodal rehabilitation,  injection therapy, physical therapy, or the application of other therapies in patients with shoulder pain are either conflicting or lacking.

On the other hand the authors state that the involvement of MTPs in musculoskeletal pain is becoming increasingly accepted. The referral of pain by active MTPs is well understood.  Although latent (pain free) trigger points are not an immediate source of pain they may elicit pain when stimulated, such as with sustained or repeated contractions.   In addition, latent MTRs may disturb normal motor recruitment patterns and movement efficiency resulting in joint dysfunction, which places abnormal stress on the joint tissues and increases the risk of injury.
Despite this evidence the authors state that the treatment of MTPs is rarely included in systematic reviews of the effectiveness of conservative interventions in patients with shoulder pain.

The trials

For the investigation of the prevalence of MTPs, 72 subjects were chosen from patients with non-specific shoulder pain aged between 18 and 65 referred to a primary care practice that specialises in neck and shoulder pain.
For each subject, all 17 muscles known to produce shoulder pain or shoulder dysfunction were examined for MTPs.  Muscles containing active MTRs were found in all 72 subjects, while muscles containing latent MTPs were found in 67 subjects.  The median number of active MTRs per subject was 6.   The most common muscles where active trigger points were found were infraspinatus (56 subjects) and upper trapezius (42 subjects).
In the investigation of treatment of MTPs the same 72 subjects were randomly divided into control and treatment groups. The treatment group had their MTPs treated by a therapist.  The outcome was measured by counting the number of MTPs remaining, and by the use of a detailed questionnaire that focused on physical function, pain and other symptoms (DASH).
At the end of the trial those in the treatment group had significantly less MTPs and showed significant reduction in pain and disability as measured by the DASH questionnaire.  Moreover, the number of trigger points and the DASH questionnaire were correlated: ie, as the trigger points disappeared the pain and disability reduced. 

Major issues raised in the “fine print”

The “fine print” of the research shows up a huge issue.   Detailed reading of the research shows that patients were treated on a weekly basis for 12 weeks.  Each treatment included:

  • multiple applications of ischaemic compression for each trigger point
  • massage
  • cryotherapy
  • specialised stretching, and
  • hold and relax techniques.

These multiple treatments would constitute a very extensive or extended consultation each session.  If done professionally the cost and time involved for 12 sessions sessions would be very considerable.   For this considerable outlay in time and expense the improvement in pain and disability (DASH score) was significant, but certainly not complete.  The mean number of muscles with MTPs went from 7.4 active and 4.2 latent to 4.8 active and 4.7 latent.  It’s an improvement, but there were still over half the trigger points still present. 
In addition, there was no measure of the residual effects after treatment was discontinued.  We do not know whether the MTPs and symptoms gradually returned

Clinical implications

The two pieces of research show clearly that MTPs are heavily implicated in chronic non-specific shoulder pain, and that their treatment should be part of a management plan.  However, 12 extensive sessions of therapy over 12 weeks produced results that of might well be described as “half fixed”.  Also, and the authors discuss the need for further investigation of perpetuating factors, while others suggest that MTPs have microscopic muscle damage, which would cause them to continually redevelop.  Taking this to it’s logical conclusion it would take considerably more than the 12 visits “fix” the problem, then further ongoing therapy indefinitely to deal with the MTPs as they re-occur due to perpetuating factors and microscopic muscle damage.


From clinical experience though that is realistic.  MTPs can be extremely stubborn.   A small number of treatments may de-activate a MTP having it revert from active back to being latent, therefore providing welcome relief.  However, as the research shows they most likely persist, causing dysfunction and so forth until re-aggravated causing pain again.


If the course of treatments as provided in the trial was extended until more complete resolution was obtained, then continued on a maintenance basis to prevent re-occurrence the results would be very worthwhile. However, this would be extremely time-consuming and expensive: something very few patients would commit to


In summary, the trial results clearly show the treatment of MTPs for non-specific shoulder pain to be a necessity.  However, having it done entirely by therapists as per the trial would be incredibly time consuming and expensive.  Most patients would not agree to this, hence it must be considered impractical.  How do we make it practical? 

A possible solution

To solve this issue we need to look at what MTRs are and how they are treated.  There is a large amount of theoretical discussion and numerous theories about what MTPs are, how they form and how they perpetuate.
MTPs are identified as having a nodule within a taut band of muscle.  When these nodules are irritated or pressed upon they exhibit a characteristic pain referral, and sometimes cause the muscle to twitch.  To simplify the theories, the nodule appears to be a hyper-contracted section of muscle with reduced microcirculation, hypoxia and a build up of neurotransmitters and other chemicals.  There also appears to be positive feedback loops involving both the local chemicals/hypoxia and the muscle proprioceptors.  The tautness appears to be due to the hyper-contracted section of the muscle shortening, hence pulling on the other parts of the fibres.

There are numerous therapies used to treat MTPs.  Each appears to target part of the complex entity to help break the feedback loops.  Dry needling and massage are thought to increase local microcirculation, thereby relieving hypoxia and removing excess chemicals.  Various stretching protocols, plus or minus the use of ice or cold sprays are thought to help break the neurological feedback loop.  Ischaemic compression where (painful) pressure is applied to the trigger point and held was originally thought to help squash the contracted sarcomeres forcing them to elongate.  However, it is speculated that it affects circulation, and the painful stimuli affects the neurological feedback loop.  Each of these therapies has achieved a moderate amount of success in clinical trials.   Note that the original researchers used multiple therapies, probably with a view of disrupting as many aspects of the feedback loops as possible.
Localised vibration massage is used extensively in practice to treat MTRs.  At this author’s college the student clinic had a stand mounted G5 vibration massager which was used very successfully.  However, no clinical trials that used this modality to treat MTPs were found.  To shed a scientific light on the use of vibration massage there are many trials showing that it 1) increases localised circulation, and 2) acts on muscle proprioceptors to cause relaxation.  These are the two components speculated to help treat MTRs and break the positive feedback loop.  Vibration massage also has the advantage of being easy to use, non-invasive, and does not cause the stress on a practitioner’s body manual massage and ischaemic compression do. All that is needed is to hold the massager head over the MTP allowing the vibrations to penetrate.
It is these aspects that were behind the development of the DrGraeme massagers.  The need was seen for something that “dissolved” MTPs like the G5 in student clinic, but in a package that was smaller, easier to use and a lot less expensive.  At the time the time the scientific research was saying that the smaller easy to use home type units were not effective and not recommended by professionals.  It was decided there was a need for a serious one to be built.
There are two ways DrGraeme massagers help make it practical for patients to receive the copious amounts of therapy needed to successfully treat conditions involving MTPs.

  • They make treatment by practitioners in clinic easier, more convenient and less stressful on one’s body.
  • Being easy to use and affordable, patients can use a massager at home under professional advice.  This allows professionals to add practically unlimited quality massage to a patients management plan.  It has the added advantage of freeing up time during a consultation.  For example, as patients are able to do much of the mundane repetitive soft tissue therapy themselves at home the time otherwise spent doing soft tissue therapy might be spent dealing other things, such as addressing biomechanical, ergonomic or other perpetuating factors.

Samples and practitioner orders

We happily supply sample massagers to degree qualified practitioners who deal with musculoskeletal complaints, on a one per clinic basis.  Please email us directly on graeme@drgraeme.com for samples or practitioner/wholesale supply.

References

Bron et. al High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain BMC Musculoskeletal Disorders201112:139https://bmcmusculoskeletdisord.biomedcentral.com/articles/10.1186/1471-2474-12-139
Bron et. al. Treatment of myofascial trigger points in patients with chronic shoulder pain: a randomized, controlled trial BMC Medicine 2011, 9:8https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-9-8
M. Saleet Jafri, “Mechanisms of Myofascial Pain,” International Scholarly Research Notices, vol. 2014, Article ID 523924, 16 pages, 2014. doi:10.1155/2014/523924
https://www.hindawi.com/journals/isrn/2014/523924/
Xiaoqiang, Z Review article Understanding of myofascial trigger points Chinese Medical Journal 2014;127 (24)
https://www.researchgate.net/profile/Qiang_Min_Huang/publication/269999790_Understanding_of_myofascial_trigger_points/links/54f05c900cf2495330e614a5/Understanding-of-myofascial-trigger-points.pdf
McDonagh D. et al Good vibrations: Do electric therapeutic massagers work? Ergonomics Vol. 48, Iss 6  2005
https://s3.amazonaws.com/academia.edu.documents/42325110/Good_vibrations_do_electrical_therapeuti20160207-26192-g2jw75.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1517551941&Signature=FUVnD2%2BaEVoH8sgc0Hbprnkd82c%3D&response-content-dispositi

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About Dr Graeme

Several years ago Dr Graeme, a Chiropractor practicing in Victoria, Australia was looking for a serious hand held massager his patients could use at home to get the extra quality massage they needed. The ones he found in the shops and on-line for home use looked nice but were not serious, and ... read more