Background: So, most recently in the past few months I've gradually developed this minor niggling ache in my racket shoulder after playing. Since it didn't hurt when playing and I could still play all my shots, I thought it was just overuse and did what most people would do... ignore it. I'm a high intermediate level player playing 2-3x per week for the past 3 years more seriously, and I've played on and off for the past 30 years, but I think my age of 46 years is slowly starting to catch up to me. Then, 2-3 weeks ago, I was going for a big fat juicy midcourt "cha-siu" smash that I was gonna drill into the mat, but ... (you know this part is coming) ... unfortunately I mistimed it and missed it completely. The forces of the swing were transferred back up into my shoulder and I immediately felt a sharp pain inside the shoulder below the AC joint. Needless to say, I couldn't continue playing that night. Despite icing and taking anti-inflammatory meds, the sharp pain continued to show itself whenever I cleared or smashed hard over 70%. Drives, drops, lifts were fine. Completely stopping badminton for a while was being considered, but I just couldn't stop for even 1 week! So, after a lot of googling and consulting with a physio friend, I came to the conclusion: shoulder impingement syndrome of the supraspinatus tendon. What's happening is the supraspinatus tendon (labelled rotator cuff tendon above) was getting overused and irritated under the AC joint, but the final blow was when I missed the smash and threw my shoulder forward forcefully and wrenched it. Apparently, this is a common injury in throwing sports (eg. baseball, football), and activities requiring much overhead arm motion (eg. swimmers, tennis players, painters). In badminton, it is due to our mostly forehand strokes. These actions cause our shoulder joint to move forward during the activity, and can even gradually cause the shoulder joint to migrate forward at rest due to the higher tone of the front shoulder and chest muscles overpowering the weaker underused rear back and scapular muscles. Additionally, most of our work and hobbies involve working with our arms in front of us (like typing on Badminton Central!) and with our bad habits of slouching our shoulders, there is even more tendency of the shoulder to migrate forward. The problem is that our shoulders and its respective tendons were not designed to function well for long in the forward position. The AC space becomes narrower and tendons swell and get impinged more, leading to the impingement syndrome. Simple diagnostic tests: Hawkins' test: Neer's test: Unspecified test, but I thought my arm was going to fall off when I attempted this! Some exercises: As one would expect, the goal of all the rehab exercises for this condition would be to cause the shoulder to go backwards into its more functional position, by stretching and loosening the chest and front shoulder muscles, and by strengthening the rear back and scapular muscles. Some links that were helpful to me: http://www.badmintoncentral.com/forums/showthread.php/14072-General-guide-to-arm-and-shoulder-injury-and-prevention by bigredlemon http://www.badmintoncentral.com/forums/showthread.php/82337-Recurring-shoulder-pain by blindaim http://www.pinnacle-ortho.com/what_hurts_specific.php?id=29 And various posts by Gollum, Fidget, and others.