Prevention and treatment of shoulder impingement

Physiotherapist and author of Postural Correction Jane Johnson has created a short video description of prevention and treatment of shoulder impingement.

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Jane sums up the overall treatment approach and provides ideas for non-invasive treatment.

The book Jane refers to in this video is Postural Correction, specifically, pages 188-190.

What is Shoulder impingement?

Shoulder impingement involves soft tissues getting ‘stuck’ in the shoulder joint and can occur in various places within the joint. For example, where the tendon of the supraspinatus muscle gets trapped beneath the acromion, the overhanging section of the shoulder blade at the top of the shoulder. Or, the tendon of the long head of the biceps brachii muscle as it creeps deep into the shoulder joint to attach to a part of the shoulder blade called the glenoid fossa. For this reason, the term ‘subacromial impingement syndromes’ is used. Sometimes, compression of the acromioclavicular (AC) joint at the top of the shoulder is included as an impingement condition too.

Why do some people experience shoulder impingement whilst others do not?

One reason could be due differences in the bony anatomy of the shoulder. Where there is a downward pointing acromion there is less space within the shoulder joint. Additionally, bony spurs on the underside of the acromion can impinge on soft tissue structures beneath it. Another reason may be poor posture, where the shoulder blades are protracted (brought around the rib cage) causing the arm bone to rest in a position of inward (internal) rotation (A). In this position, the humerus rotates inwardly around its long axis and a bony prominence at the head of the humerus called the greater tubercle, which would normally not affect shoulder function detrimentally, now catches on the acromion when the arm is moved above chest height.

Prevention and treatment of shoulder impingement

What are the symptoms of shoulder impingement?

Clients with impingement at the shoulder often get a painful ‘arc’ of movement when they attempt to take their arm above chest height. If the arc of pain is experienced when the arm is raised in front of the body to chest height and above, this is more likely to be impingement of the biceps brachii tendon. Impingement of the supraspinatus tendon can give rise to pain in a mid-range arc when the arm is abducted. Problems with the AC joint tend to give rise to pain when the arm is above the head, by the ear, as in this position the AC joint is compressed. Often soreness is felt on the front of the shoulder.

Test yourself

Where impingement is the result of poor posture, a person may stand with their shoulders protracted and their arms internally rotated. You can test for this by observing the position of a colleague’s hands. In standing, our hands normally rest with the palms facing the thigh but with increasing inward rotation of the arm, the palms begin to face backwards; the position of the elbow changes. Observe the elbows of the subject in photo (B). Her left arm is inwardly rotated. If it were not, the left elbow would be more visible, as it is on the right.

Internal rotation is also assessed using muscle length tests.

When a client has pain at the anterior shoulder region it is important to rule out other causes. There could be many, including a strain of the anterior fibres of the deltoid muscle or the upper aspect of the biceps brachii muscle or its tendons.

How is shoulder impingement treated?

Shoulder decompression surgery can be performed. Jane is working on a future post with a video demonstrating this. Prophylactically and unless the condition is considerably advanced, non-invasive treatments are a useful first intervention. An overall four-step approach is helpful:

Rest

An obvious, first step in treatment is to eliminate arm movements that bring on symptoms. The video that accompanies this blog was made in response to a question asked by a therapist treating a client who regularly performs weight training. It can be challenging for clients who are used to exercising regularly to abstain or modify their regime, but this is essential.

Overhead weight training, throwing and racket sports are obvious examples of activities likely to aggravate symptoms of shoulder impingement. Impingement syndromes do not only affect sportspersons. Anyone whose occupation or hobby involves the likelihood of increased protraction of the scapula combined with internal rotation of the humerus could be at risk of developing this condition and modification of tasks is always the first important step. Aggravating factors associated with everyday activities might include prolonged driving with the arms outstretched, gardening activities such as reaching up to prune plants or painting and decorating.

Posture

The second step in treatment could be to change thoracic posture. Kyphotic postures aggravate shoulder impingement syndromes because it is in this posture that the scapulae protract around the rib cage, bringing with them the internally rotated humerus. Clients need to be encouraged to practice thoracic extension in order to maintain a more neutral, upright thoracic spine. There are a great many exercises to achieve this and these will be explained in detail in a future post. A neutral thoracic position facilitates the third step.

Positioning

A third step is for the client to adopt a position in which the scapulae rest neutrally as opposed to in a protracted position. The rationale for this is that in a more neutral position, the humerus is permitted to hang naturally, rather than in an inward rotation. This is achieved by strengthening the lower fibres of the trapezius muscle in conjunction with rhomboids: practising depression and retraction of the scapulae.

The fourth step sometimes gets overlooked, therefore most noteworthy. It is to reduce internal rotation of the humerus. This is explained in detail below.

Treatments to correct internal rotation of the arm

Techniques therapists can do include gentle traction of the shoulder joint (C). Anterior-posterior glides of the shoulder joint (D) to stretch the soft tissues on the front of the joint providing this does not cause pain. Gentle passive external rotation of the shoulder in sitting (E) or supine (F) positions. These will result in passively stretching internal rotator muscles. Taping of the shoulder can also be useful (G).

C – Gentle traction of the shoulder joint

D – stretching the soft tissues on the front of the joint

E – Sitting passive external rotation

F – Supine passive external rotation

G – Taping

Techniques a client can do

Clients with a shoulder impingement should note and avoid any postures or arm movements that increase symptoms and passively stretch the internal rotators of the arm. This could be as simple as resting with the injured arm on pillows if the degree of rotation is severe (H) or performing any one of a large number of stretches for the front of the shoulder and arm (I). One of the most important aspects of self-care is strengthening the muscles of external arm rotation. Exercises can be performed in a variety of positions such as with the arm at the side (J) or abducted (K) or using resistance bands (L). External rotation exercises are ineffective when the scapulae are protracted around the ribcage as in kyphotic postures and so external rotation exercises should only be started once the thorax is in a more neutral position.

H – In severe cases a client may only be able to rest the injured arm on pillows

I – Stretching the front of the shoulder and arm

J – External arm rotation, using a resistance band

K – Another example of how to use resistance bands

L – Seated external rotation

These examples and photographs provided here for both therapist interventions and client self-care are only a small selection of many possible variations. As a result, each would need to be modified to suit an individual with shoulder impingement. There is no preferred order or number of exercises.