The biceps brachii is probably the most known muscle there is, it's the muscle we flex for the girls or we activate to bring another sip of beer to our lips. It typically consists of two separate heads (in some individuals may be three - wild), the long and short heads. Today we're gonna focus on the long head, it's tendon, and what to do if said tendon slips. The long head arises from the supragenoid tubercle of the scapula where the tendon travels laterally through the glenohumeral joint, enclosed in a synovial sheath, curves in an inferolateral direction to travel along the intertuberculus sulcus (it is held in sulcus by transverse humeral ligament, so ligament interlink should be checked if recurrent) and the muscle attaches to the radial tuberosity of the humerus in conjunction with the short head. It flexes and supinates the forearm, and even forms a mechanical link with the supraspinatus when the arm is in aBduction. The scapular attachment is what makes it a huge player in shoulder injuries. Now for the fun stuff- muscle test and treatment- all of which are in the video above! For the muscle test, we have the patient flex arm to 90 degrees and external rotate to THEIR extent, it varies from person to person. The doctor extends the arm through the sagital plane to se if patient can hold that position. If they can't, you can challenge the long head tendon either medial to lateral or lateral to medial to see if theirs tendon involvement, if any of these strengthen the muscle test we know we have to reset the tendon. I like the modified kocher maneuver for this. This is best achieved with the patient against the wall. We start by holding up the shoulder at the elbow with our OUTSIDE hand, making sure the patient gives us all their weight. Then we externally rotate to their maximum (no need to dislocate their shoulder) and bring the shoulder across the body and into internal rotation - don't let that shoulder move. We then traction the arm down to the side of the body, cover the AC joint and bring it up. Congratulations the shoulder is now reset- remember to always recheck your work via muscle testing and enjoy! :)