I’ve noticed before that some yoga poses are easier to do on certain sides of my body. However, I never really investigated further. Since starting my yoga teacher training program, I’ve dived into a quest for knowledge. Having a side by side image of my arms in Cow Face Pose (Gomukhasana) gave me a clearer vision on the difference between the tightness on the left vs right side of my body.

After further research and with the help of my doctor (3 months until med school graduation) husband – we figured out the difference is not in my “up” arm but the “down” arm; the parts that creates extension in my shoulder and full internal rotation. [more info after picture]

This Yoga Journal article explains further  – “The muscles that limit movement into this position are those that perform external rotation and flexion of the shoulder. The muscle primarily responsible for shoulder flexion is the deltoid (the shield-shaped muscle that forms the “cap” over the shoulder), assisted by the clavicular (originating on the collarbone) part of the pectoralis major, and the biceps brachii and coracobrachialis (both are muscles of the front of the upper arm). The prime movers in external rotation are the teres minor and infraspinatus. Both originate on the scapula, cross the back of the shoulder joint, and insert on the upper outer humerus.”

Possible causes for the tightness in my shoulders/arms:

• Carrying my purse everyday my left shoulder – “we maintain our bags on our shoulders by lifting our shoulders to keep our bags from falling down our arm. Over time, the muscles of the shoulder develop tightness from over contraction or being used for too long.” (source – Kip Yates, LMT)
  
• Stronger/tenser muscles in my left (dominant) arm especially in the pectoralis, deltoid and biceps

Possible solutions/life modifications:

• Alternate to carrying my purse on my right shoulder
• Pectoral Stretch at the wall exercise (more info here)
• Stretch and lengthen the shoulder flexors and external rotators – “Spend one minute twice a day with your forearms stacked behind your back and your hands reaching toward your elbows. Keep your chest lifted and open, and breathe into your upper chest and front shoulders. As the stacked-forearm position becomes more comfortable, start to work one hand up your back, gradually moving it up between the shoulder blades. Again, keep your chest lifted and your shoulders back and down. Once you can get your hand up between your blades, you have a shot at catching the fingers with the “up” arm.”