Yoga Anatomy: Reducing Shoulder Impingement
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.
TRY THESE TECHNIQUES
Knowing the potential for shoulder impingement, we can apply a couple of movement techniques to retain more subacromial space and reduce compression and stress going into the tendon and bursa sac.
The first movement application is external rotation of the humerus, when you abduct and/or deeply flex the shoulder joint. When the upper arm bone internally rotates during abduction and/or flexion, the greater tubercle moves more closely into the subacromial space thus increasing the potential for impingement. When we externally rotate the upper arm bone, it shifts this boney process somewhat away leaving more space for the supraspinatus tendon and bursa sac.
The second movement we can employ is scapular upwards rotation. The shoulder blade can be taken through 6 movements – one of them is an upwards rotation. When we significantly abduct or flex the shoulder joint, we want the shoulder blade to move with the upper arm bone (this is called scapulohumeral rhythm). Besides sustaining more fluid joint congruency and connection during these arm movements, maintaining this joint rhythm reduces the onset of shoulder impingement. Upwards rotation of the scapula is similar to a spinning movement of the shoulder blades away from the spine causing the socket and acromion process (all connected as one bone) to tilt upwards. The upwards lift of the acromion retains space in the subacromial space as the arm bone lifts through abduction or flexion.
When we combine external rotation of the shoulder with upwards scapular abduction, this becomes a movement of integrity and beauty for the shoulder joint – retaining space while enhancing stability. Consider all the yoga postures and transitions where you can take advantage of this movement combination: sun salutation arm circles; downward facing dog; tree pose; crescent lunge/warrior 1; half moon; and other reaching side bends.
Play with these movements in the shoulder and shoulder girdle. Keep in mind that bone structure can be highly variable, therefore some people benefit more from these movement applications than others. Also examine with these movements how the rest of the body (and kinetic chain of other joints involved like the elbow and wrist) is affected. Rarely in yoga are movements tightly isolated in one joint region. As you find your way into postures, maintain ease and playfulness (versus rigidity) as this will greatly increase your capacity to explore these techniques towards spaciousness and integrity.
What Really Happens in Hip Openers
One of the most common requests heard in a yoga class is hip openers today please. This request is usually followed by the other half of the class groaning. We love to hate hip openers yet our bodies crave them and often feel lighter and more open after — for good reason. The majority of us sit for most of our days, shortening the hip flexors at the front of the hip (psoas, rectus femoris, sartorius) and tightening the hip rotators (piriformis, obturator internus, gamellus, to name a few).
A Look Inside the Hip
The hip joint itself is a ball and socket type joint with the head of the femur (thigh bone) sitting in the acetabulum or socket of the pelvis. A variety of muscles attach into the femur starting from the pelvis itself, the lumbar spine, the sacrum, or other parts of the femur. Hip openers could affect any of the muscles surrounding the hip depending on the position of the joint at the time of the pose.
In general when we stretch or open a muscle we are lengthening its position, moving the two attachment points away from each other. This is easy to assess with linear muscles like the psoas which attaches from the front of the lumbar spine, crosses through the pelvis and attaches to the head of the femur. If we flex the hip forward we are shortening the psoas, bringing the two attachments of the muscle closer together. If we extend the hip backwards (such as in the back leg of Pigeon pose we are opening and lengthening the psoas. The effect becomes greater in King Pigeon pose if we assume an upright posture with our spine so that we lengthen the upper attachment more. In this example we can also rethink our definition of hip openers. Suddenly, poses with a bent knee where we rotate the hip are not the only way to open our hips. If the psoas attaches into the femur, and a shortened psoas tightens our hip (not to mention the affect it has on our low back) then poses like Warrior / Virabhadrasana or Half Moon / Ardha Chandrasana become hip openers too.
Rotate to Open a Rotator
The rule of how to open a muscle becomes less clear with the hip rotators where the angle of the joint actually affects the action of the muscle. For example, the piriformis muscle attaches from the front of the sacrum to the back of the femur. It acts as an external or outward rotator of the hip. Except if the hip is flexed, then it assists in abduction or sideways movement of the hip. So to follow the rule of opening we would want to internally rotate the femur, flex the hip and adduct or bring the femur towards midline. This can be achieved with the top leg in Marichyasana (sit with your left leg extended, bend your right knee and step the foot across your left thigh so that the femur is flexed, adducted toward midline, and gently internally rotated.) Other hip openers don’t seem to follow the rule of opening. We often externally rotate the hip to stretch the external rotators of the hip. Huh? The reason this works is because we typically flex the hip at the same time.
Use Your X-Ray Vision
To understand how hip openers work we have to picture the position of the muscle. Let’s picture the obturator internus muscle, a close friend of piriformis. It attaches from our sitting bone or ischial tuberosity to the greater trochanter of the femur, a bony outcropping on the side of the hip. We can feel both of these pieces of bony anatomy. Our ischial tuberosities can be felt when sitting, they are the bony bits under the flesh of our buttocks. Our greater trochanter can be felt by first finding the top of our pelvis by by placing our hands at our waist, firmly pressing in and down until we feel a ledge. This is our iliac crest. Slide your hands down and with your thumb you will feel a bony prominence that is the femur. You can feel it move by slowing rotating the hip in and out. So now we can feel the attachment points for the obturator internus, between the ischial tuberosity or sitting bone, and our femur. From this observation we can see that in a neutral position the muscle wraps around the hip. So if were to flex the hip, the ischial tuberosity scoops under thus increasing the space between the two attachment points and increasing the wrapping distance of the muscle – hence lengthening the muscle. This is why a simple squat (using the term simple lightly) can stretch our hip rotators and can be one of the reasons Westerners find it so challenging to achieve.
Opening Our Hips to Open to Possibility
Since there are many muscles in the hip with many functions depending on the demands we place on our body, keeping these muscles supple can help us in ways that may not seem obvious at first. Hip openers may help us attain a standing pose we’ve been struggling with, or they may help us get down on the ground easily to play with our kids or our kitten. Traditional yogic thought attributes many healing properties to hip openers from organ issues to sexual dysfunction. So if you are one of the groaners when hip openers are suggested, perhaps pause to wonder if they could be helping you in ways you weren’t even aware.