SUPRASPINATUS (NOT SHOWN)

SUBSCAPULARIS (SHADED)

INFRASPINATUS

TERES MINOR

PECTORALIS MAJOR

PECTORALIS MINOR (LIES BENEATH PECTORALIS MAJOR

TERES MAJOR

LONG HEAD OF TRICEPS

LONG HEAD OF BICEPS

© Primal Pictures 2010 Figure 1: The muscles of the rotator cuff The accessory muscles of the scapula (trapezius,

serratus anterior and posterior and levator scapulae) stabilise, rotate, protract and retract the scapula on the chest wall to maintain full GH contact. Thus a deficient RC allows the prime mover muscles to cause mal-articulation and this in turn be a cause of secondary impingement.

If the stabilisers don’t work effectively, the prime movers either work inefficiently or may attempt to take on the role of the stabilisers. This invariably leads to pain and reduction of movement, which compounds the initial problem.

+ A good practitioner will familiarise themselves with all the

muscles outlined above along with their attachments, to fully understand their actions, both concentrically and eccentrically.

EXAMINATION A good history and examination will often help locate the source of the shoulder ‘problem’.

Pain from the true shoulder (GH joint) is mostly felt in the lateral upper arm, but can travel down to the thumb. Myofascial pain from the scapula muscles will travel down the C6/7 dermatomes (1). I favour an approach that involves look, move and feel.

The order is more ‘physio-like’ to encourage the full range of movement (FROM) possible before one causes pain by palpation. Firstly the patient undresses down to skin/bra.

Look n Observe the height of the shoulder (often the injured/ dominant one is held higher) n Then ask the patient to raise each arm with thumb up (ie. full external rotation) to full abduction/flexion, slowly observe the scapula-thoracic motion (should be a smooth glide with no hitching or catching) and then lower the arm again. A painful arc will present at 60-90 degrees if there is a rotator cuff problem, above 135 degrees is more likely to indicate an AC problem. Look for muscle atrophy and pseudo-winging of

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Video 2: Normal abduction

KEY POINT: As we’ll see throughout this series of articles, a recurring theme is that the stabilising muscles have to work effectively before the prime movers can work efficiently.

the scapula (often due to trapezius weakness).

Move n External rotation - I stand behind the patient, elbows at their side, 90 degrees flexion, neutral supination/pronation, I hold the elbows to their side and ask them to push their hands as far apart as possible. This assesses the gleno- humeral joint, the first movement affected by an intra-articular problem. Note that abduction then flexion is affected in that order - this is the capsular pattern of the shoulder. Usually a female patient can get to 90 degrees of external rotation, a male often can on only get to 75 degrees - the key is equality between each shoulder i.e. on both the left and right sides. Decreased external rotation indicates a GH problem2

.

n Internal rotation - I then ask the patient to move their hands up their back towards a real or imaginary back of bra (internal rotation). Measure internal rotation by landmarks reached (e.g. back pocket, posterior sacroiliac spine (PSIS), lower edge scapular, spine of scapular) limitation usually indicates a rotator cuff problem. Treatment can then be accurately applied.

See videos 2, 3 and 4 for normal abduction, external rotation and internal rotation respectively. Then you need to assess power:

n I stand behind the patient then pin their elbows down with Figure 2: The muscles that act as primary movers of the shoulder

LATISSIMUS DORSI

DELTOID

LATERAL HEAD OF TRICEPS

sportEX medicine 2010;44(Apr):9-12