To effectively treat the shoulder. You must know the anatomy of it.
Neck Muscle Anatomy - Health, Medicine and Anatomy Reference Pictures
neck muscles anatomy - Google Search
Neck Muscle anatomy
Forward Head and Neck Muscle Imbalance
Neck Muscles Anatomy - Anterior Triangle - Part 1
Muscles of the Face (Facial Muscles) - Medical Illustration, Human ...
Da Vinci's anatomy sketches love em