First, I have to say that the GST Fundamentals course is far and away the best program that I have done, huge thank you Coach Sommer and the GST Team!
A bit of background, I am a former NCAA DI and national level athlete (softball, Canada). My background in softball has given me pretty good range of motion and strength in the shoulders, but I have had, and continue to have, very limited range of motion and mobility in the hips. I haven't been able to sit cross-legged on the ground comfortably since I was about 5 (see photos for current ability). I had an MRI done last year and was diagnosed with the very broad SI Joint Dysfunction (no impingements, or arthritis detected), for the past 18-24 months my glut. med. on the left side has felt more like an old, tight, leather belt than a supple soft tissue. Sitting is not good for it, so I am doing the best I can to avoid sitting for long periods of time, I have a standing desk, and am on my feet quite a bit at work. Physiotherapy, acupuncture, and massage only provided short-term relief so I decided to start from the beginning and give GST a try to see if I could correct a movement pattern or position.
I have completed the Fundamentals course and have gone back through it over the past 3 months to improve positions, but the hip mobility remains quite restricted. There have been great improvements in hamstring, calf, ankle, and wrist flexibility, core strength, and thoracic mobility, I am very happy about the progress overall! I don't expect changes overnight, but would be sincerely appreciative of any advice/insights/comments in general or in reference to the attached photos.
Many thanks.

