Rotator Cuff Rehab Manual Centering
Manual centring the humeral head during rotator cuff exercises.
Optimal glenohumeral kinematics are dependent on an accurate location of the centre of rotation in the glenohumeral joint, which is important to balance external loads and to balance internal muscle forces (1). Obligatory translations and joint centre migration does occur during physiological movement of the upper limb but needs to be controlled. An interruption in this optimal glenohumeral kinematics can lead to increased translations of the humeral head.
A novel approach to rotator cuff rehab.
Symptomatic shoulders exhibit small, but significantly greater, translation in the anterior and posterior direction when compared to asymptomatic shoulders (2). Superior migration of the humeral head is considered to have a space reducing effect on the subacromial space. In fact, patients with rotator cuff tendinopathy, but not full tears, have been noted to have excess anterior superior translation of the humeral head when doing active arm elevation by up to as much as 3mm in the anterior direction (2–5), and between 1.0mm and 1.5mm in the superior direction(3,4).
The force couple between the deltoid and the rotator cuff controls humeral centring in the glenoid. Muscle peak isometric concentric and eccentric torque has be shown to be impaired in patients with rotator cuff tendinopathy compared to asymptomatic patients (6–8).
However, in some patients despite targeted cuff rehab they fail to regain the correct muscle length tension relationship in the cuff and restore normal mechano-sensory function and hence centring of the humeral head in the glenoid. The patient responds well to rehab but reports to episodic periods of 'pain’ and/or ‘movement’ and/or ‘clicking or crunching ‘in the shoulder. In these patients this approach to of rehab is most useful. In these cases I combined cuff rehab/cuff timing/cuff control type exercises while manually centring the humeral head. While maintain this centred HOH the patient then does the required cuff exercise. The direction of the HOH relocation differs between patients and sometimes a combination of glides in a few planes is necessary. You will know you have the correct HOH relocation when during the exercise you eliminate the 'pain or ‘click’ or sensation of 'movement'’. See vidoes below.
If the humeral head is suspected to be migrating superiorly stimulation of the latissimus muscle and the subscapularis muscle can lead to a dynamic centring of the humeral head during cuff rehab. See videos below.
References1. Berthonnaud E, Herzberg G, Morrow D, An K-N, Dimnet J. In vivo location of joint canters of the shoulder system gleno-humeral and scapulo-thoracic joints between two postures describing the arm elevation in the plane of scapula using techniques based upon biplanar radiography. Journal of Mechanics in Medicine & Biology. 2006 Dec;6(4):385–97.
2. Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Physical Therapy. 2000 Mar;80(3):276–91.
3. Deutsch A, Altchek DW, Schwartz E, Otis JC, Warren RF. Radiologic measurement of superior displacement of the humeral head in the impingement syndrome. Journal of Shoulder and Elbow Surgery. 1996 May;5(3):186–93.
4. Hallstrom. Shoulder rhythm in patients with impingement and in controls [Internet]. 2009 [cited 2012 Aug 6]. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2823181/?tool=pmcentrez
5. Paletta Jr. GA, Warner JJ., Warren RF, Deutsch A, Altchek DW. Shoulder kinematics with two-plane x-ray evaluation in patients with anterior instability or rotator cuff tearing. Journal of Shoulder and Elbow Surgery. 1997 Nov;6(6):516–27.
6. MacDermid. Validation of a new test that assesses functional performance of the upper extremity and neck (FIT-HaNSA) in patients with shoulder pathology [Internet]. [cited 2012 Aug 6]. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892014/?tool=pmcentrez
7. Tyler TF, Cuoco A, Schachter AK, Thomas GC, McHugh MP. The Effect of Scapular-Retractor Fatigue on External and Internal Rotation in Patients With Internal Impingement. Journal of Sport Rehabilitation. 2009 May;18(2):229–39.
8. Warner W, Lj M, Le A, J K, R K. Scapulothoracic motion in normal shoulders and shoulders with glenohumeral instability and impingement syndrome. A study using Moire topographic analysis. Clinical orthopaedics and related research. 1992 Dec;(285):191.