Xiaopeng Troubleshooting: Shoulder External Rotation

I was having trouble with Xiaopengs forward and backward, both with the thumb maintained parallel to the ground, and pointed to the ground when in extension (as I understood Coach Sommers' advice to be). Among the problems are that when my right arm is transitioning from directly overhead to extension during a forward Xiaopeng, or extending during the backward Xiaopeng, I get a little bit of pain in the right shoulder, and some clicking/popping beneath the scapula/in the ribs. And in general, even unweighted I found my shoulders were getting a bit sore though I had a form check done and my form was ok. Part of that may have been overtraining, so I've cut back. The clicking seems to be evidence of a deficit though.

I sought out a local physiotherapist, not sure if she is correct but she suggested that the problem was stemming from:

• weakness in external rotators of the shoulder
• tightness in the right pectoral
• tightness in the thoracic spine

Interested in any general feedback on the problem and/or her thoughts, but also on whether there are exercises in GB that specifically address shoulder external rotator strength which I could start (I'm still on PE1), or other exercises for shoulder external rotators anyone might suggest. If anyone with expertise has alternative suggestions I am very interested as well. I do the stretch series, including thoracic bridge, so hopefully that plus some rolling will help the pec and thoracic tightness. 

Thanks for any insight.

HI MIke actually there are a good number of exercises in the Foundations 3 for hollowbackpress and also a good stretches for chest. Actually the biggest obstacle in your case it is the presence of tight internal rotator, if you do not release them you will never have a decent amount of benefits on external rotator training. for resume your spine and pec mobility I suggest thoracic spine stretch course.

Thanks Alessandro -- I'm still doing PE1 in F1, and hesitate to buy F3 until I've made more progress. Are the F3 exercises not a bit advanced in any case? As I understand it, doing additional PE>iMs is recommended, but we are supposed to limit our progress in the PEs themselves to the prescribed sequence. 

What are the best ways to release tight internal rotators?