As the answers have said above, I do agree that this is a multi faceted pathology. I’m leaning towards The Proximal Long Head of Biceps Tendon for the below reasons. 1: The pain & discomfort is located within the anterior aspect of the shoulder. 2: The Hand to Head impact leads me to think that the Trauma to The Biceps Tendon has not only compressed and Jarred the whole region from Shoulder/Scap/Delts/Biceps/Triceps through the velocity of the punch that would effect the hand, wrist & forearm as well. This also has the potential to Sublux or Dislocate The Biceps Tendon out of The Bicipital Groove which can come with worst case ramifications of surgical intervention that can change the whole anatomical structure. 3: Aggravating factors: Hand To Head punch with high velocity & power = Abduction & Flexion most likely to create engagement in The Bicipital Groove. Hand behind back: I’d like to know if the SubScap Liftoff Test was positive or negative for pain and or loss of strength. Pressing: This will allow the tendon to activate if possible depending on how severe the injury is which I would need further testing to see if this person could even begin this movement safely. Driving through: Again creates stress to the Biceps Tendon & as above I would need further testing to see if this movement is safe for this person to do in the first place which depends on the damage sustained. I will try not to get too in depth with this next part as it begins to over complicate the situation, however I believe that it is still relevant to this scenario. On the other side of this rationale brings me to the Rotator Cuff that will be involved in not only Biomechanics but the whole Musculoskeletal Region & allow for the factor of compensation that will be happening out of protection. As far as treatment goes, I would be treating the Biceps, Triceps, Deltoids, Shoulder, Scap, Trap, Lat etc as I’m now bringing in the whole Shoulder Girdle or Pectoral Girdle that brings all four joints in to play - SC, AC, ST & GH remembering that this may well have had an impact on the Manubrium of the Sternum.