Research Review By Dr. Jeff Muir©


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Date Posted:

September 2022

Study Title:

Exercise rehabilitation for neurogenic thoracic outlet syndrome: a scoping review


Luu D, Seto R & Deoraj K

Author's Affiliations:

Division of Research and Innovation, Canadian Memorial Chiropractic College, Toronto, ON; School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada

Publication Information:

Journal of the Canadian Chiropractic Association 2022; 66(1): 43-60.

Background Information:

Thoracic outlet syndrome (TOS) has historically described a compromise of blood vessels or brachial plexus fibers between the base of the neck and shoulder. Several variants have been identified, including vascular, arterial and neurogenic, with the latter (NTOS) referring specifically to compression of the brachial plexus that results in pain in the neck/arm and paresthesia in the fingers (1). NTOS can exist as a “true” version, where pain is accompanied by objective findings, and a “disputed” version, where pain lacks corroborating objective findings (2-4). As a result, some consider the condition over-diagnosed, with estimates of 2-3 cases/100,000 people/year (1). Complicating this is a lack of consensus regarding diagnostic criteria.

NTOS treatment generally entails conservative management via manual therapies, hot/cold therapy, electrical modalities and strapping as needed (5). Exercise therapy is a cornerstone of this conservative approach to treatment, despite a lack of reviews of specific exercise protocols and their efficacy. The authors therefore sought to conduct a scoping review of exercise programs for NTOS, with a secondary goal of reviewing the rationale behind specific exercise programs.

Pertinent Results:

Eligible Studies:
47 articles met the inclusion criteria, the majority of which were narrative or literature reviews (n = 26), with the remainder consisting of retrospective reviews (n = 5), prospective studies (n = 3), non-randomized trials (n = 3), case series (n = 3), case studies (n = 5) and clinical commentaries (n = 2).

Exercise Alone vs. Exercise with Other Treatment Modalities

Peet’s Protocol:
Peet’s protocol dates to 1956 and focuses on combining strengthening of the levator scapulae and pectoralis minor stretching with postural correction exercises. The clinical rationale is restoration of muscle balance and postural correction through strengthening of muscles that help to open the thoracic outlet by raising the shoulder girdle and stretching the muscles that close the thoracic outlet. There is disagreement; however, on which muscles need strengthening versus stretching (5) and little beyond anecdotal evidence is available to support the protocol.

Britt’s Method:
Britt’s method borrows from Peet’s protocol but adds shoulder girdle exercises via a strapping device that elevates the shoulders (6). Cervical retraction, shoulder girdle stretching, resisted shoulder exercises and shoulder girdle/pectoral strengthening exercises are also keys to Britt’s method. Exercises are recommended 5-10 times/day. Limited evidence supports this protocol.

Scapular Mechanics:
Shoulder girdle depression can accompany NTOS and lead to altered scapular mechanics, which can traction the brachial plexus. Exercises in this approach are designed to elevate the shoulder girdle (7). Initially, normal muscle recruitment is addressed, followed by movement and load management to maintain scapular control. Exercises focus on shoulder abduction and flexion, with a goal of improving muscle firing, although the objective evidence supporting this approach is limited, with the majority of evidence in the form of narrative reviews.

Nerve Gliding Exercises:
The use of tendon and nerve gliding exercises can be combined with range of motion, pendulum, stretching and strengthening exercises, with a goal of decreasing intraneural pressure and reducing intrinsic irritation of the surrounding tissues (8). Nerve gliding exercises are generally designed to improve neural mobility while also increasing shoulder girdle strength. Some protocols limit exercise focus to the brachial plexus while others extend exercises to include median and radial nerve gliding at the elbow and wrist. Duration varies but 4-6 months of exercise has been recommended in many cases. Again, clinical experience is offered as support of this protocol in most cases.

Restoration of Breathing Mechanics:
Aerobic conditioning such as walking or diaphragmatic breathing were suggested in several articles to be combined with stretching and strengthening exercises. Encouraging rib depression during breathing is recommended to discourage overuse of the paraspinal and neck musculature. Several studies of varying levels of evidence provide support for this exercise approach.

Exercise dosage:
Recommendations on dosage (frequency, sets, repetitions) varied broadly across studies. Recommendations generally involved multiple sets of exercise multiple times per day (Peet’s protocol, Britt’s method, scapular focused protocol) while others recommended strengthening exercises once or twice daily for up to six months (8,9). At a minimum, exercises methods such as scapular mobility have been recommended as little as once per week for up to 12 weeks (10).

Clinical Application & Conclusions:

While the authors were able to identify 47 articles describing exercise protocols for NTOS treatment, the vast majority of these were low level studies or clinical opinion, with no randomized controlled trials found. As such, the majority of evidence is anecdotal and widely varies, evidenced by the variety of dosage recommendations for exercise programs. Randomized trials are needed to determine which if any form of exercise is superior as well as to determine appropriate exercise dosage.

As we await more evidence in this space, conservative therapy remains the front-line approach for this condition. The combination of conservative interventions like exercise and manual therapy (applied to the thoracic, cervical spine and upper ribs) should be the basis of an initial treatment plan.

Study Methods:

The scoping review was conducted per the methodology of Levac et al. (6). Pubmed searches up to March 2021 included English language articles of any level of evidence (from narrative reviews and clinical opinion to systematic reviews of randomized controlled trials). Articles including diagnoses of true or disputed NTOS were eligible for inclusion while those including arterial or vascular TOS, cadaveric studies or those with poorly described exercise protocols were excluded. Two reviewers completed the searches while 1 other reviewer was available to settle disagreements. Two authors extracted relevant data from eligible articles. Common themes were determined based on exercise program and rationale and exercises were categorized based on biomechanics or properties.

Study Strengths / Weaknesses:

  • Conformed to previously published guidelines for scoping reviews.
  • A comprehensive search strategy was used.
  • Broad and/or open-ended search criteria increased the likelihood of finding eligible articles.
  • Non-English language studies and those describing post-operative rehabilitation were not included.
  • The broad definition of what constituted “sufficient detail” in the description of exercise programs caused disagreement between reviewers and could have resulted in some articles being overlooked, and
  • Only Pubmed was searched for relevant articles.

Additional References:

  1. Illig KA, Rodriguez-Zoppi E, Bland T, Muftah M, Jospitre E. The incidence of thoracic outlet syndrome. Ann Vasc Surg 2021; 70: 263-272.
  2. Wilbourn AJ. Thoracic outlet syndromes: a plea for conservatism. Neurosurgery Clin North Am 1991; 2(1): 235–245.
  3. Wilbourn AJ. The thoracic outlet syndrome is overdiagnosed. Arch Neurol 1990; 47(3): 328–330.
  4. Mailis A, Papagapiou M, Vanderlinden RG, Campbell V, Taylor A. Thoracic outlet syndrome after motor vehicle accidents in a Canadian pain clinic population. Clin J Pain 1995; 11(4): 316–324.
  5. Lo CC, Bukry SA, Alsuleman S, Simon JV. Systematic review: The effectiveness of physical treatments on thoracic outlet syndrome in reducing clinical symptoms. Hong Kong Physiother J 2011; 29(2): 53–63.
  6. Levac D, Colquhoun H, O’Brien KK. Scoping studies: advancing the methodology. Implementation Sci 2010; 5: 69.
  7. Watson LA, Pizzari T, Balster S. Thoracic outlet syndrome part 2: conservative management of thoracic outlet. Man Ther 2010; 15(4): 305-314.
  8. Hanif S, Tassadaq N, Rathore MF, Rashid P, Ahmed N, Niazi F. Role of therapeutic exercises in neurogenic thoracic outlet syndrome. J Ayub Med Coll Abbottabad 2007; 19(4): 85-88.
  9. Robey JH, Boyle KL. Bilateral functional thoracic outlet syndrome in a collegiate football player. N Am J Sports Phys Ther 2009; 4(4): 170-181.
  10. Pesser N, Goeteyn J, van der Sanden L, et al. Feasibility and outcomes of a multidisciplinary care pathway for neurogenic thoracic outlet syndrome: a prospective observational cohort study. Eur J Vasc Endovasc Surg 2021; 61(6): 1017-1024.

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