THE SHOULDER GIRDLE, sometimes referred to as the shoulder complex, is a very versatile and mobile structure made up of more than one joint. Shoulder injuries in yoga are common and are more likely to build up over time rather than happen without warning.
Both the shoulder and hip are ‘ball-and-socket’ joints but when you compare the structures, the hip joint socket is more profound, enclosing the femur, which makes it more stable but less mobile than the shoulder joint. The shoulder socket is a looser structure that allows greater mobility but can also make the shoulder joint less stable and more prone to injury and dislocation.
The shoulder joint is stabilised by muscles, tendons and ligaments which allow an incredible range of motion.
The hip joint is designed to be a weight-bearing joint, while the shoulder isn’t. Bearing weight through the shoulders can strengthen the upper muscles and improve bone density in the arms and spine, but it is not designed to handle prolonged or repetitive weight-bearing activities. So lengthy Sun Salutation sequences that include Downward dog – Chaturanga – Upward dog will challenge its design since throughout it you are asking your shoulder joint to repetitively work between flexion, extension, internal and external rotation, all while bearing weight.
This can lead to rotator cuff injury, for example, when the tendon of the supraspinatus muscle gets sandwiched between the bones of the shoulder blade and the arm. Supraspinatus is one of four rotator cuff muscles that assist in lifting the arm and stabilizing the shoulder joint.
Supraspinatus impingement usually happens due to mechanical impingement or repetitive microtrauma. For example, a mechanical impingement could be caused if you were to fall and break the fall with your arm. The head of the humerus will forcefully press into the joint and pinch the tendon(s).
Repetitive microtrauma happens because of overuse in the overhead position. There is a combination of inherent joint instability, muscular imbalance, and significant repetitive stress on the static and dynamic shoulder stabilisers.
If you have loose shoulders and sit at a desk all day, your shoulders internally rotate, causing muscular imbalance. If you were to then do a power yoga class and start loading up your shoulder joints with repetitive Sun Salutations, it could make your shoulders vulnerable. Do it enough times and you’ve got yourself some shoulder pain, at the very least.
If your shoulder joints are not that loose to begin with, you are more likely to have difficulty with maintaining proper form, which requires external rotation of the shoulders, causing repetitive misalignment that can also lead to a shoulder injury.
If you want to put even more stress on your shoulders then throw in some prolonged weight-bearing moves that place too many movements involving the same joint in a row, causing cumulative stress
In the above sequence, both your shoulders and your wrists are prone to strain. By weight-bearing in one pose after another without any break in between, instead of strengthening the muscles – which was probably your original intention – you are stressing and destabilizing your joints.
Cumulative stress is usually a combination of repetitive tasks, mechanical compression and sustained/awkward positions – all of which occur in the sequence above. If you are repeating the sequence several times, you are asking the joint to support most of your body weight, sustaining this awkward position (by our everyday movement standards) for quite some time. The possible results include:
- Dislocation – the head of the humerus pops out of the shoulder socket
- Bursitis – inflammation of the bursa (a fluid-filled sack that serves as a cushion between two rubbing surfaces)
- Tendonitis – irritation of the tendons
- Impingement of the tendons (which we discussed earlier)
These injuries are common in young athletes who use their arms overhead for swimming, baseball, and tennis; and those who do repetitive lifting or overhead activities, such as construction or painting. Now yoga practitioners can join the ranks!
You should not stop doing Sun Salutations or Side Planks (unless you already have shoulder pain – then you should stop them!) but you should limit the cumulative stress that you place them under.
The phrase ‘prevention is better than cure’ is a fundamental principle of yoga. Therefore, it makes sense to prevent shoulder injuries rather than heal them later.
