Explore the Anatomy and Correct Alignment of Headstand Pose

Our wonderful shoulders are the most mobile joints in the body and, for anyone who has done any amount of Hatha Yoga flow, we can appreciate how much the shoulders are engaged and challenged in our practices.  Given how frequently we load and stress the shoulders in yoga, it is ideal to move the shoulders with intelligence, mindfulness, and attentive care. One aspect of mindful movement and engagement is reducing the onset of shoulder impingement.

Our shoulder joints are made from a ‘ball and socket’ design. The upper arm bone (humerus) has defined structures at its proximal end (closest point to the center of the body).  At the proximal end of the shaft, we see that the humerus has boney processes (called tubercles where tendons attach). Moving towards the shoulder joint, the humerus has a neck that transitions into a ‘head’ or the ball portion of the joint.  The humeral head inserts into the socket (glenoid fossa or cavity) forming this highly moveable joint.  The socket is part of the shoulder blade (scapula bone).  There is another part of the shoulder blade with a boney projection called the acromion process which is positioned above the humerus. You call feel the acromion process on yourself by taking one hand over and to the back of the shoulder blade. Run your fingers along the shoulder blade to find a horizontal line of bone – this the spine of the scapula. Run your fingers all the way to the end into your shoulder  – where this ends is your acromion process.

Between the acromion process and the tubercle region of the humerus is the ‘subacromial space.’ This is where our attention goes regarding shoulder impingement considerations. Deep above the spine of the scapula runs one of your rotator cuff muscles (supraspinatus muscle), which has its tendon traveling through the subacromial space and attaching onto the greater tubercle of the humerus. To offer some protection to this tendon, there is a small sac of fluid (bursa sac) between the tendon and the acromion process.

When we stand in Mountain pose (arms relaxed), there is ample space in the subacromial space for the supraspinatus tendon and the bursa sac. When we lift our upper arm bone outwards (abduction) or towards certain angles of significant forward movement (flexion), the humerus closes into the subacromial space. For some people, due to bone structure and reduced subacromial space, they are more prone to having the tendon and/or bursa sac being compressed and stressed (aka shoulder impingement). With frequent compression, the tendon and/or bursa sac may develop conditions of inflammation. As with any acute or chronic development of shoulder impingement conditions, you will want to consult a qualified health professional for proper assessment and therapeutic treatment.