The Rotator Cuff - Subscapularis
The subscapularis is one of the four muscles that make up the rotator cuff group. The rotator cuffs are group of muscles that, along with their tendons, pretty much act to stabilise the shoulder. Of the four muscles that make up the rotator cuff group, the subscapularis is the most powerful.
The muscle itself originates from the inside of the scapula (shoulder blade) and then inserts itself on a small bump (lesser tuberosity) on the front of the arm (humerus). You can see this by viewing the image above.
The job of this rotator cuff is internal rotation (to turn the arm inwards). Problems and tightness in this muscle restricts shoulder function and can play a role in shoulder pain and discomfort although out of the four rotator cuffs it is the least likely to get injured. However just to be safe, its best to stretch and strengthen this muscle on both sides.
If the arm turns inwards when contracting, we need to turn it away (external rotation) to stretch it. The pose that springs to mind is Gomukhasana arms. I have used an image from Ray Long's website below to give you a better look at what your subscapularis does when in Gomukhasana arms. From the image below you can see that adequate pectoral and lat flexibility is also required for the pose. So if you cannot do this pose, it doesn't necessarily mean your subscapularis is tight. Maybe the other surrounding muscles are also restricting your movement. That is why yoga anatomy can be so frustrating and confusing. Everything is theory and nothing is really that straight forward. However let’s assume that your lats and pecs are not "tight'. In that case Gomukhasana should not only stretch your subscapularis on the side where your arm is reaching overhead, but also potentially strengthen the subscapularis on the other arm that has to internally rotate so you can reach for your finger tips behind your back.
Are you still there? 😏
Anytime you reach behind you by bringing the hand over head, you go into EXTERNAL rotation of the shoulder. This is the movement required to stretch the subcapularis. Think King Pigeon Pose and Dancer (image of Iyengar below) as other examples.
The subscapularis is also an important muscle in stabilising your shoulder. In downward facing dog, the susbcapularis moves the shoulder blades away from the middle (abduction) allowing them to "flatten" rather that stick up.
In conclusion, a healthy and balanced group of rotator cuffs will keep your shoulders mobile, and assist in keeping your shoulders stable in a number of yoga asanas. Strong, stable shoulders are the key to a number of static poses where the shoulders play a key role. Think downward dog, chatarunga, arm balances and even your headstand.
Zahir Akram has a number of qualifications in Human Biomechanics (the understanding of human movement) and Anatomy & Phsysiology. Zahir will be teaching various modules of our yoga teacher training programme beginning in May 2017 and is available for 121 bookings. For more information contact Zahir on 07577 422132.