Friday 2nd August, 2019
  Categories: Practitioners

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 and found 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 had reduced, and there was a corresponding decrease in the pain and disability scores. From this we can conclude that MTPs are heavily involved in non-specific shoulder pain, and their treatment is a must.

However, after the 12 extended weekly therapy some pain and disability was still present. More importantly, examination showed that about 2/3 of the trigger points remained, although many had reverted to their latent (pain free) form. Simply, only about one third of trigger points had actually been eliminated. Further, the authors state that due to microscopic damage an the presence of causative and aggravating factors the trigger points may redevelop. The complete elimination of trigger points therefore would take a much larger number of applications of therapy, plus some sort of ongoing maintenance. This would be economically prohibitive if relying on professional therapy alone.

Challenging the conventional diagnosis of shoulder pain

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. They point out that the following facts contradict this.

  • Calcifications, acromion spurs, subacromial 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. They are said to contribute to shoulder pain the following ways.

  • 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.
  • 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

Subjects

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.

Trial one: prevalence

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).

Trial two: treatment

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).

Treatment

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, plus hold and relax techniques.

Results

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. A summary of the results follows.

  • Average MTPs at start: 7.4 active and 4.2 latent
  • Average MTPs after 12 weeks: 4.8 active and 4.7 latent
  • 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

Correct diagnosis and treatment of shoulder pain

The results of these trials contradict the common diagnosis and treatment of shoulder pain. Instead, it strongly implicates MTPs a major cause, and points to their treatment as a major priority.

The requirements of care

There is a discussion of the treatment of MTPs elsewhere on this website. However, 12 extensive sessions of therapy over 12 weeks produced results that of might well be described as “half fixed”, and the authors suggest that factors may cause it to continually redevelop. Taking this to it’s logical conclusion it would take considerably more than the 12 visits then further ongoing care to “fix” the problem. If done by professionals alone this would be prohibitively expensive for most people. A solution would be supplementary home massage using a DrGraeme massager under professional advice. 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 Disorders 201112:139

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

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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