Shoulder instability is usually to the anterior (front) aspect of the joint however it can also occur in other directions with posterior (back) being the next most common. Instability of the shoulder can be managed both conservatively or through surgery. The ideal perception is that surgery should only be done if your do not want to re-dislocate the glenohumeral joint however there are many factors that need to be considered including:
- How frequently the joint dislocates
- How long the joint is out of position for
- What sport or activities the person participates in
- Any previous surgery
It has been found that in individuals 35yrs or older, 65% also have full thickness rotator cuff tears when they dislocate their shoulder anteriorly. Therefore the management approach will also depend on what tears are also present. Repeated dislocations also tend to lead to osteoarthritis in the joint later in life. Surgery at the time may reduce the osteoarthritis in the early years but 10yrs on the levels of osteoarthritis are likely to be similar. Research has also shown that alcoholics with repeat shoulder dislocations are likely to experience a greater amount of osteoarthritis (Dr Rod Whiteley – Physio Network Masterclass 2020). Reduction of the dislocation needs to be done by an appropriately trained medical professional.
When taking the conservative approach to management and rehabilitation after a shoulder dislocation there are a few things that it is important to remember. Firstly, you need to learn to control the activation of pec major and learn to switch it off as this muscle provides the strong anterior pull that often results in the dislocation. The role of the rotator cuff muscles, particularly those fibres that are at the posterior aspect of the joint, is a compressive one. They hold the head of the humerus against the glenoid cavity, therefore holding the arm in position.
Scapular (shoulder blade) positioning is important. If we hold the scapula back during movement then we are reducing the range of motion available at the shoulder joint. During activity we actually want the scapula to rotate upwards and out so that it clears the chest wall and ribs. This then allows for forward and backwards movement of the shoulder joint.
Dr Rod Whiteley recommends perturbation based training where the arm is raised into a position of risk. External forces are then applied one at a time from different directions, obviously gently in the early stages of rehab. This trains the muscles to react correctly to the force. An alternative to this is shown by Heath Williams, of Principle Four Osteopathy, at https://principlefourosteopathy.com.au/shoulder-stability-training-pertubation/. Heath demonstrates perturbation training using a stiff arm at 90 degrees of flexion and then using a power band to challenge the stability of the shoulder joint. Traditional strength training is not as effective in stability training as it is not reactive to forces.
Falling training is also beneficial in the rehab program post shoulder dislocation, particularly if the injury occurred through a fall. As with any exercise it should be progressed from least stress to most so you would start with falling onto 2 arms with towels under the chest. This allows for compression of the landing surface if the shoulder does feel unstable. You can then progress to 1 arm landing and then to landing on the back of the shoulder as you roll.
Myotherapy can help you with switching off pec major and determining the right level of activity and exercise to improve the stability of your shoulder joint to allow you to return to your normal activities. Book now.