Research Review by Dr. Shawn Thistle©

Date:

May 2007

Study Title:

The effect of anterior versus posterior glide joint mobilization on external rotation range of motion in patients with shoulder adhesive capsulitis

Authors:

Johnson AJ et al.

Publication Information:

Journal of Orthopaedic & Sports Physical Therapy 2007; 37(3): 88-99.

Summary:

Primary adhesive capsulitis, or frozen shoulder, is an oft diagnosed condition describing insidious painful stiffness in the glenohumeral joint. Secondary adhesive capsulitis is associated with a known condition in the shoulder, such as previous fractures, dislocations, avascular necrosis, arthritis, stroke, etc. The primary form is relatively common, thought to affect 2-3% of the general population. In fact, it is the main cause of shoulder pain in patients aged 40-70.

This condition can have a profound impact on patient quality of life, work and athletic capacity, sleep, and general daily function. It also presents a unique and sometimes frustrating problem to deal with clinically. Even though the condition is considered to be self-limiting, the typical 2-3 year timeframe for recovery is often unacceptable to patients, which explains why many of them seek manual and conservative care.

Although the exact pathology of adhesive capsulitis has not been determined, most experts agree that inflammation of the joint capsule and synovium is a facilitating event, leading to the formation of adhesions in the capsule itself. These adhesions essentially cause a "contracted capsule" that severely limits glenohumeral mobility, holding it tightly against the glenoid fossa. As such, the capsule is not actually "stuck" to the humeral head as the term “adhesive capsulitis†suggests.

Clinically, adhesive capsulitis presents as globally restricted active and passive ROM of the shoulder, with external rotation most severely affected. It can also be extremely painful. The literature to date has been unable to provide a universally accepted regimen of therapy, despite the variety of techniques and modalities that are commonly utilized.

There is some evidence to suggest that joint mobilization can reduce the rotational deficit seen with this condition, however the optimal direction of mobilization has not been determined. This randomized clinical trial compared the effectiveness of anterior versus posterior glide mobilizations for improving glenohumeral external rotation in a group of patients with adhesive capsulitis. Twenty consecutive patients presenting with a specific external rotation deficit (see below) were randomized to receive 6 therapy sessions involving either anterior or posterior joint mobilizations.

Patients were included if they met the following criteria:
  • no history of diabetes, thyroid problems, or cervical spine injuries
  • no previous treatment for the condition
  • diagnosis was primary adhesive capsulitis
  • age 25-80
  • radiographic examinations within the previous 12 months were read as normal
  • no previous shoulder surgery
  • external rotation deficit - external rotation deficit had to worsen (i.e. external rotation decreased) as the arm was abducted (the authors based this on previous clinical and anatomical studies - this pattern is thought to suggest capsular versus muscular restriction)
  • if external rotation was equally limited as the arm was abducted, the patient was not included in the study
Each of the six therapy sessions (performed over 2-3 weeks) began with 10 minutes of ultrasound (1MHz for the posterior capsule in the group receiving posterior mobilizations and 3MHz for the anterior capsule in the other group). Directly following the ultrasound, the mobilization procedures were administered (see below).

Patients were also advised to avoid resisted shoulder motions (ex. pushing, opening/closing stiff doors etc.), and no home exercise program was given. The mobilization procedures were performed as stretch mobilizations, loading the restricted tissue at a slow rate, maintaining low load over a long period (no oscillatory motions). The mobilizations were performed as follows:
  • Anterior Mobilization - with the patient supine, the therapist maintained lateral humeral distraction in midrange position while an anterior mobilization was performed at the end range of abduction and external rotation. Patients were progressed to a prone position (with the force applied from the posterior aspect) as they could tolerate further stretch.
  • Posterior Mobilization - with the patient supine, the therapist maintained lateral humeral distraction while the posterior stretch mobilization was performed at the end range of abduction and external rotation. Patients were progressed to posterior mobilization in end range of flexion and external rotation as tolerated.
  • stretch/mobilization positions were held for a total of 15 minutes in each treatment session
Outcome measures in this study included external rotation (measured at full available abduction). Subjects also completed a shoulder questionnaire, focusing on impairments generally seen with adhesive capsulitis.

Pertinent Results:

  • there was no significant difference in external rotation ROM between groups prior to the treatment
  • 2 patients (10%) left the study before completing the 6 treatment sessions
  • patients in the posterior mobilization (PM) group increased their external rotation ROM by 31.3° on average (standard deviation 7.4°, p<0.001) while the anterior mobilization (AM) group only increased by an average of 3° (SD 10.8°, p=0.40)
  • this difference was significant, and was evident by the third treatment
  • the largest improvement in the AM group (18°) was less than the smallest improvement in the PM group (22°)
  • both groups showed a significant decrease in pain levels by the end of the treatment sessions

Conclusions & Practical Application:

This study, despite its small study group, provided strong statistical evidence that a posterior glide mobilization/stretch applied after ultrasound was superior to an anterior maneuver for increasing the external rotation deficit seen with primary adhesive capsulitis. These findings are in agreement with previous studies.

The authors recommend careful evaluation of these patients for signs of muscular restriction causing decreased external rotation. If external rotation ROM increases with progressive arm abduction, they suggest assessing and treating the subscapularis muscle (those that practice ART® or any other soft tissue technique would likely second this recommendation).

On the other hand, external rotation ROM that becomes less with arm abduction may suggest capsular tightness, which may explain why the posterior glide mobilization used in this study was successful. In patients with restricted shoulder ROM, prudent assessment and treatment of the subscapularis should be performed, and may prevent an erroneous diagnosis of adhesive capsulitis in some cases.

Although unlikely, the slightly different application of ultrasound in the treatment groups may have had an influence on the results of this study. Future studies should attempt to identify which patients would benefit most from mobilization or soft tissue therapy, as well as the importance of applying ultrasound before the procedures, and which settings are most beneficial.