Research Review By Dr. Jeff Muir©

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Date Posted:

May 2021

Study Title:

Effect of Manual Therapy Interventions on Range of Motion Among Individuals with Myofascial Trigger Points: A Systematic Review and Meta-Analysis

Authors:

Guzman-Pavón MJ, Cavero-Redondo I, Martinez-Vizcaíno V et al.

Author's Affiliations:

Faculty of Physiotherapy and Nursing, Universidad de Castilla-La Mancha, Toledo, Spain; Health and Social Research Center, Universidad de Castilla-La Mancha, Cuenca, Spain; Rehabilitation in Health Research Center (CIRES), Universidad de las Americas, Santiago, Chile; Facultad de Ciencias de la Salud, Universidad Autonoma de Chile, Talca, Chile; Universidad Politecnica y Artıstica del Paraguay, Asuncion, Paraguay

Publication Information:

Pain Medicine 2022; 23(1): 137–143.

Background Information:

Myofascial pain is a significant cause of musculoskeletal pain and is among the most common causes of healthcare visits and disability (1, 2). Myofascial pain is typically characterized by myofascial trigger points (MTP) – hyperirritable regions within the bands of skeletal muscle. MTPs are often associated with predictable patterns of pain referral and are characterized by increased muscle tension and shortening, muscle weakness/fatigue and decreased mobility (3, 4). MTPs are diagnosed on physical examination, one of the key components of which is evaluation of range of motion (ROM). Although there is little evidence to support a cause-effect relationship between ROM changes and MTPs, evidence noting that alterations in ROM are present in myofascial pain patients is available (5). The objective nature of ROM also makes it a potentially valuable tool in diagnosis and treatment evaluation.

Treatment for MTPs includes manual therapies, which are popular due to their non-invasive, non-pharmacological nature and their low cost and safety characteristics. Relevant manual therapies range from ischemic compression (6) and stretching (7) to manual release techniques to soft tissue mobilization techniques (8, 9).

Manual techniques are well-accepted for the general treatment of MTPs, although the evidence specifically in support of these treatments for the impaired ROM associated with MTPs is scarce. The goal of this study, therefore, was to systematically review and meta-analyze the evidence for manual therapies as a method for increasing ROM in patients with MTPs.

Pertinent Results:

Eligible Studies:
Initial searches identified 15 158 studies, of which 26 underwent full-text review. 13 RCTs (including a total of 768 participants) were subsequently identified as eligible for this review/meta-analysis. Of the eligible studies, 1 focused only on male participants and 1 focused only on women; the remaining studies included mixed populations. The average age of participants ranged from 15.9 to 46.9 yrs.

Study Characteristics:
5 studies addressed active MTPs while 10 studies focused on latent MTPs. The specific manual therapies employed across the studies varied widely. Pressure release was the most commonly used, followed in descending order of commonality by: ischemic compression, stretching, post-isometric relaxation, strain-counterstrain, positional release, massage techniques, muscle inhibition and manipulation. Frequency of treatment for the manual therapies ranged from 1-3 sessions/week and treatment plans ranged from 1-3 weeks in duration.

Risk of Bias Assessment:
Risk of bias concerns were noted in all studies. Randomization was rated as low risk for 92.4% of studies, 0% showed deviations from intended interventions, 100% showed bias in missing outcome data, 84.7% showed bias in the measurement of results and 100% showed bias due to selection of the reported results and missing outcome data.

Efficacy of Manual Therapy on ROM:
The pooled effect size for manual therapies on ROM was 0.52 (95% CI: 0.42-0.63) – this is a medium effect size. Heterogeneity was low across eligible studies (I2 = 16.0%).

When evaluated based on the specific manual therapy used, the effect size for compression techniques was 0.58 (95% CI: 0.39–0.76) while that for stretching techniques was 0.57 (95% CI: 0.39–0.76). In studies reporting ROM in centimetres, the effect size was 0.36 (95% CI: 0.14–0.59), and for those reporting ROM in degrees, the effect size was 0.57 (95% CI: 0.47–0.68).

A stepwise sensitivity analysis showed no significantly modified results. No publication bias was found using Egger’s test assessment (p = 0.187).

Clinical Application & Conclusions:

The evidence indicates that manual therapies may be effective in increasing ROM in patients with MTPs. The treatment method utilized does not seem to influence the outcome and treatment success, as adequate mobility is a necessary element for functional movements. The authors suggest that future studies should include the effect of manual therapies on joint mobility in patients with MTPs, as well as determine the most effective manual therapy for MTPs.

EDITOR’S COMMENT: notwithstanding the ongoing controversy about the mere existence of MTPs (for the record, I think some patients are prone to ‘having’ them, while others simply aren’t), this paper tells us that: 1) we still need more work in this area; and 2) that almost any manual therapy technique will have some effect on ROM in patients that (seem to) have MTPs. If you find hyperirratible ‘spots’ in your patients’ musculature – it is reasonable to spend a few minutes trying to reduce this sensitivity via some sort of manual, hands-on technique, acupuncture, or something else. In my experience, this helps the rest of your treatment (SMT, for example), have a greater clinical impact.

Study Methods:

Searched databases included: PubMed, Scopus, Cochrane, Web of Science (WoS), and Clinical Trials.gov from their inception to May of 2021. Search terms included those related to: MTPs, clinical trials, manual therapy and ROM. Two reviewers independently searched databases, with a third reviewer available to resolve potential disagreements.

Study Characteristics for Inclusion:
Studies were eligible based on: study design (RCTs only), participants (patients with MTPs), type of intervention (manual therapy, any type), comparison (control group) and outcome (ROM).

Data Extraction:
Two reviewers extracted the following data: author/date of publication, type of MTP and location, sample size/sex distribution/mean age, intervention, and measured outcomes.

Risk of Bias:
Two reviewers assessed risk of bias using the Cochrane Collaboration’s tool for assessing risk of bias (RoB2) (10). The tool contains 5 domains: randomization process, deviations from planned interventions, missing outcome data, measurement of the outcome and selection of the reported results. Each domain is scored as having a low, moderate or high risk of bias.

Data Synthesis and Analysis:
For ROM outcomes, the effect size and 95% confidence interval were calculated using the DerSimonian-Laird random effects model (11). Effect size was interpreted as: 0.2 indicates a small effect, 0.5 indicates a medium effect and 0.8 indicates a large effect. Heterogeneity was assessed using the I2 statistic. Subgroup analyses were performed with stratifications based on: manual therapy intervention type and measurement method (cm vs. deg). Sensitivity analysis was performed in a step-wise manner and publication bias was estimated using Egger’s test.

Study Strengths / Weaknesses:

Strengths:

• Broad but relevant search criteria.
• Clinically relevant research question and reasonable, useful conclusions.
• Followed PRISMA guidelines and pooled eligible data based on specific criteria to assess heterogeneity.

Weaknesses:

• Diagnosis of MTPs was somewhat inconsistent in the literature and did not always follow Travell and Simons’ criteria (3).
• The number of eligible studies was relatively small
• Follow-up was relatively short and comorbidities were not considered as confounding variables

Additional References:

1. Gerwin R. Diagnosis of myofascial pain syndrome. Phys Med Rehabil Clin N Am 2014; 25(2): 341–55.
2. Fleckenstein J, Zaps D, Ruger LJ, et al. Discrepancy between prevalence and perceived effectiveness of treatment methods in myofascial pain syndrome: Results of a cross-sectional, nationwide survey. BMC Musculoskelet Disord 2010; 11(1) :32.
3. Simons D, Travell J, Simons L. Travell Simons myofascial pain and dysfunction. In: The Trigger Point Manual. Volume 1. Upper Half of Body. 2nd ed. London: Lippincott Williams & Wilkins; 1999.
4. Lucas KR, Rich PA, Polus BI. Muscle activation patterns in the scapular positioning muscles during loaded scapular plane elevation: The effects of latent myofascial trigger points. Clin Biomech 2010; 25(8): 765–70.
5. Mayoral del Moral O, Torres Lacomba M, Russell IJ et al. Validity and reliability of clinical examination in the diagnosis of myofascial pain syndrome and myofascial trigger points in upper quarter muscles. Pain Med 2018; 19(10): 2039–50.
6. Aguilera FJ, Martın DP, Masanet RA, et al. Immediate effect of ultrasound and ischemic compression techniques for the treatment of trapezius latent myofascial trigger points in healthy subjects: A randomized controlled study. J Manipulative Physiol Ther 2009; 32(7): 515–20.
7. Grieve R, Cranston A, Henderson A, et al. The immediate effect of triceps surae myofascial trigger point therapy on restricted active ankle joint dorsiflexion in recreational runners: A crossover randomised controlled trial. J Bodyw Mov Ther 2013; 17(4): 453–61.
8. Kojidi MM, Okhovatian F, Rahimi A et al. Comparison between the effects of passive and active soft tissue therapies on latent trigger points of upper trapezius muscle in women: Single-blind, randomized clinical trial. J Chiropr Med 2016; 15(4): 235–42.
9. Gemmell H, Miller P, Nordstrom H. Immediate effect of ischaemic compression and trigger point pressure release on neck pain and upper trapezius trigger points: A randomised controlled trial. Clin Chiropr 2008; 11(1): 30–6.
10. Higgings P, Savovic H, Page M, Sterne J. Revised Cochrane risk of bias tool for randomized trials (RoB 2). 2019. Available at: https://methods.cochrane.org/bias/resources/rob-2-revisedcochrane-risk-bias-tool-randomized-trials (accessed September 20, 2020).
11. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials 1986; 7(3): 177–88.