Research Review By Dr. Robert Rodine©


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Date Posted:

November 2010

Study Title:

Thoracic Outlet Syndrome Part 2: Conservative management of thoracic outlet


Author's Affiliations:

LifeCare Praham Sports Medicine Centre, Praham, Australia & the Musculoskeletal Research Centre, La Trobe University, Bundoora, Australia

Publication Information:

Manual Therapy 2010; 15: 305-314.

Background Information:

Within this 2 part series, Watson et al. attempt to clarify some misunderstandings regarding TOS and help guide clinicians in its diagnosis and management. In part 1, the authors provided a brief overview of the presentation, clinical manifestations, differential diagnoses and clinical examination for TOS (See link below for Part 1 which was also reviewed).

Part two of the series addresses a rehabilitative model which can be utilized subsequent to reaching a diagnosis of TOS.

Recall how part one classified TOS into categories of vascular or neurological, and then into several sub-types from there. The purpose of doing so is to have an advantage of understanding the mechanism which produces symptoms and then further developing a treatment plan tailored to that individual’s needs.

The authors of the current paper state that the majority of patients with TOS fall under the category of symptomatic TOS (sTOS). The authors state the sTOS is often due to repetitive use or overhead activities and is associated with many activities which lead to intermittent compression of the neurovascular bundle. The authors continue to postulate that there is a strong postural contribution to the development of symptoms and as such, propose the correction of scapular mechanics as part of the treatment plan.

(EDITOR’S NOTE: I would add that addressing upper thoracic mobility, cervical spine soft tissue restrictions and joint restrictions and any additional shoulder movement disorders can also be very helpful).

While manual therapists will inherently argue that there are many approaches that can be taken in the treatment of TOS, the authors of the present paper focus on a single interventional strategy which aims to address the graded restoration of scapular control.

Pertinent Results:

To start, the authors state that a position of a dropped shoulder is predominant in sTOS patients, that being a depressed scapula with possible components of downward rotation and/or anterior tilting (1). It is felt that this positional abnormality produces tractional stress upon the structures of the thoracic outlet.

Scapular malposition is identified through movements such as shoulder abduction and flexion. During these movements, patients are likely to demonstrate either delayed or insufficient upward rotation of the scapula compared to the non-symptomatic side (or to normal subjects). Scapular delay is most notable during abduction, whereas flexion is most likely to demonstrate positions of scapular winging.

(EDITOR’S NOTE: readers should review the 2 part review on the Disabled Throwing Shoulder which includes an explanation of SICK Scapula syndrome and scapular dyskinesis – links below)

The authors postulate that poor muscle recruitment patterns are responsible for poor scapular motion, though no EMG research in a TOS population exists to support this theory. The authors propose the use of muscle testing in order to determine areas of decreased strength/function. Based on the clinical experience of the authors, they submit a consistent pattern of weakness within the upper and middle trapezius on the affected side. This is often followed, they contest, with increased recruitment within the pectoralis minor, levator scapulae and rhomboids major/minor.

Once dysfunctional patterns have been identified, the authors propose a final test of manual scapular correction (involving elevation and upward rotation) to observe symptom response. If symptoms resolve, then biomechanical correction will likely sustain symptom.

(EDITOR’S NOTE: we also review a paper on the Scapular Repositioning Test – link below).

The authors propose a multi-step process in order to properly rehabilitate patients through scapular dysfunction.
  • Scapular Setting and Control - This step is where their program begins…with the patient focusing on maintaining normal scapular muscle recruitment and position while at rest. The aim of the scapular control work is to place the scapula in a normal position via therapist feedback on muscle recruitment and positioning. Once achieved, the patient will progress through the lower ranges of flexion and abduction. This stage of rehabilitation is pivotal as it sets the stage for subsequent progressions.
  • Initial Phase - The aim of the initial phase is to control scapular positioning during early abduction (up to 30°). The authors state with clinical experience that many TOS patients with depressed scapulae require assistance in rotating the scapula upward during this initial phase via a mild shoulder shrug at approximately 20-30° of abduction (EDITOR’S NOTE: I might disagree with this point if the person had a Type 3 Scapular Dyskinesis [see Disabled Throwing Shoulder reviews] – in which case scapular stability via the lower trapezius and serratus anterior would be a focus in this phase). The authors also point that during this stage of the rehabilitation, the patient’s humeral head positioning must be assessed as insufficient rotator cuff recruitment strategies may present.
  • 45-90° of Abduction - The aim of this phase is to control the scapular positioning above 45° of abduction; centralizing the humeral head position during the movements; and to load muscles which display weakness. It is important to recognize that this phase of care allows for the introduction of rubber tubing type resistance. As the patient is able to control the scapula to 45° of abduction, they should be progressed to 70°, and then 90°. Once here, strengthening drills should be added for the middle and lower trapezius. This is achieved with prone horizontal extension maneuvers while maintaining scapular control. These maneuvers are also highly effective at strengthening the posterior deltoid, supraspinatus, infraspinatus and teres minor (again, see Related Reviews for more information).
  • Flexion Control - At this stage, scapular control during arm flexion should be reassessed. It is most likely that the patient will exhibit scapular winging and therefore serratus anterior weakness. The authors recommend against using exercises such as the ‘wall push-up’ for serratus strengthening as it tends to excessively activate pectoralis minor (EDITOR’S NOTE: the literature suggests that “push-up with a plus” and “dynamic hugs” would be good options to activate SA). Therefore, the authors recommend recruiting the serratus by setting the scapula and maintaining this control while externally rotating the humerus and moving the arm through a functional abduction range.
  • 90° of Abduction and Functional Progressions - This stage of rehabilitation follows the same principles previously outlined, however is primarily relevant in patients which require higher ranges of overhead strength. Proceed carefully however at this stage however as the authors caution that if progressed to early, some patients may have their symptoms provoked.
With respect to expected outcomes, the authors present that their clinical experience has shown improvement in resting scapular positioning by 6 weeks of rehabilitation, and through active ranges through an additional 12 weeks of rehabilitation (total rehabilitation duration ranging from 12 weeks to 6 months).

Clinical Application & Conclusions:

Watson et al. have done an excellent job of presenting a clinical review series relating to TOS. While there is a paucity of relevant EMG research and outcomes studies, the hypothesis is reasonably sound and offers clinicians further insight into treating this difficult condition.

It is most important for clinicians/therapists to focus heavily on scapular control/setting early in the rehabilitation program.

(EDITOR’S NOTE: keeping the sparse nature of the existing TOS literature in mind - this recommendation is, of course, in addition to all other treatment modalities being employed – soft tissue therapy, manipulation, acupuncture are all reasonable options).

From here, patients should be progressed accordingly.

Study Methods:

Similar to part one of this series, the study’s design is that of a narrative review. No search strategy, inclusion/exclusion criteria or search results are offered. Instead the authors present literature as it pertains to supporting their hypothesis.

Despite this flaw, the authors present their theory in a linear and clinically relevant manner which enables the reader to easily follow and adapt their clinical thinking.

Study Strengths / Weaknesses:

Similar to part one of the series, the most prominent limitation of this manuscript is reflected in its narrative design and reliance on the authors’ clinical experience.

As in the presentation of a single-case design, the authors use the existing literature in a manner which supports their hypothesis. While this is a limitation, it is in no way a flaw of the presentation. Manuscripts such as this are the starting point for interventional theory, and an opportunity for clinical discussion. If we can look past this bias and reflect upon the content, we are likely to gain insight and knowledge into an alternative approach for our patients.

Therefore, while we should read everything with a grain of salt, we should equally reflect upon an entire document prior to assessing its value to our practice.

Additional References:

  1. Moore KL and Dalley AF. Clinically oriented anatomy, 5th ed. 2006. Lippincott Williams & Wilkins.
  2. Upton AR, McComas AJ. The double crush in nerve entrapment syndromes. Lancet 1973; 2(7825): 359-62.
  3. Aligne C, Barral X. Rehabilitation of patients with thoracic outlet syndrome. Ann Vasc Surg 1927; 85(6): 839-57.
  4. Barkhordarian S. First rib resection in thoracic outlet syndrome. J Hand Surg 2007; 32(4): 565-70.
  5. Novak et al. Outcome following conservative management of thoracic outlet syndrome. J Hand Surg 1995; 20(4): 542-8.
  6. Ryan GM. Thoracic outlet syndrome. J Shoulder and Elbow Surg 1998; 7(4): 440-51.
  7. Ranney D. Thoracic outlet: an anatomical redefinition that makes clinical sense. Clin Anat 1996; 9(1): 50-2.
  8. Lindgren KA. Conservative treatment of thoracic outlet syndrome: a 2 year follow-up. Arch Phys Med Rehab 1997; 78(4): 373-8.