Many Yoga poses and flows involve large movements at the shoulder joint. Some of these movements have the potential to create shoulder impingement when improper technique and movement lines are applied. If this shoulder impingement continues over time, chronic injury can form leading to pain and disfunction.
What is Shoulder Impingment?
Shoulder impingement is caused when the arm is lifted above the line of the shoulder. The head of the arm bone (humerus) lifts and rotates into a portion of the shoulder blade (acromion on the scapula). Covering the head of the arm bone are the 4 rotator cuff muscles: the supraspinatus, the infraspinatus, the subscapularis, and the teres minor. Acting as cushioning against pressure and friction, there are bursa sacs that lie between the muscular capsule and the acromion.
When the arm is lifted high over the level of the shoulder, the head of the humerus presses into the acromion. This pressure and friction can develop into inflammation of the bursa (bursitis) or the tendons the muscles (tendonitis). This inflammation can worsen due to repeated impinging actions that can eventually lead to increased pain and limited movement.
Where can Shoulder Impingement Occur in a Yoga Practice?
Shoulder impingement can occur in variety of Yoga postures and flows. Here is list of common yoga postures that set the arm bone above the line of the shoulder and can generate damaging frictional forces in the shoulder joint if one is not mindful:
*Sun Salutations-the motion raising the arms outwards in Mountain pose prior to folding into  Uttanasana often incorporates a large sweeping motion of the arms over the head that draws the humerus into the acromion.
*Extended Side Angle Pose (Parsvottanasana)
*Extended arms in Child’s Pose (Balasana)
*Half Moon Side Stretch Pose
*Gate Pose (Parighasana)
How Reduce the Incidence of Shoulder Impingement in Yoga Poses?
The first method in reducing the pressure caused by shoulder impingement is to eliminate arm transitions that move the arm bone through large sweeping motions. In Sun Salutations, consider keeping arms in the forward plane, instead of lifting arms out to the side, back, up and then over head. By lifting the arms forward instead, there is less pressure being created against the head of the humerus as the arm bone moves back and up. Â Overall, consider the path of movement when taking the arms into key yoga postures/transitions and avoid excessive circling motions that pull the arm fully back, around, and then overhead.
The greatest amount of pressure tends to occur where the arm is situated high above the shoulder line with the arm bone back in line with the neck and the arm bone rotated internally (medially) so the palm faces forward.
If the yoga posture requires the arm to be overhead and in line with the neck (like Extended Side Angle Pose), take extra note of the position of the hand. The hand should be turned inwards towards the body creating an external rotation of the arm bone. This external rotation has a tendency to draw the head of the humerus down from the acromion and scapular structures. This outwards rotation of the arm bone offers secondary benefits as it encourages the shoulder blades to draw down away from the ears, thus bringing more integrity to the shoulder girdle and freedom to the trapezius and neck regions.
If you are ever experiencing regular pain in the shoulders, consult a health care professional to have your condition properly diagnosed and treated. Continue to acknowledge that Yoga poses are a means to create expansion and vitality. With mindful alignment and awareness to joint positioning, you can maintain space and energy flow through the shoulders and readily avoid impinging movements.
Kreg Weiss 