Overhead lifts

"Another common mistake is lifting weights higher than shoulder level or bringing weights behind the the plane of the body." P. 188 Complete Conditioning for Tennis, E. Paul Roetert & Todd S. Ellenbecker.

This is a quote from a book on tennis. But the similarity in movements between tennis and longsword are relevant . This is also common advice for baseball pitchers.So, for longsword guys the overhead lifts are a potential problem. Due to the high stress on the shoulder from doing overhead sport actions the overhead lifts should be avoided. This is also common advice for baseball pitchers.

So do an incline press instead of the shoulder press (and do a vertical pull exercise as well e.g. lat pulldown, pull-ups, dips etc.). And only do cleans for Olympic lifts, not the snatch or jerk.

To explain, a little anatomy first: the head of the humerus rests in a socket, the glenoid cavity. Above the socket is the acromion, a projection off the scapula. In between these two is the subacromial space, which has to fit tendons, muscle and bursa.

Lifting the humerus above about 90* tends to compress the subacromial space. This can be lessened by strengthening the rotator cuff muscles. Healthy, strong rotator cuff muscles will help the head of the humerus move correctly, so that it doesn't impinge.

However, strengthening the muscles that pull the humerus upward will not reduce the upward compression of the humerus against the arcomion.

Overhead work, like house painting, and overhead sports, like pitchers and tennis, involve much more upward movement of the humerus. Most people bodies can't tolerate a large amount of overhead movement of the arm. There is variation in this characteristic; differences in acromion shape, glenoid cavity health, rotator cuff health and strength, and history of injury will all effect the likelihood of developing impingement.

Motion at the edge of a range of motion increases the likelihood of chronic injury. So overhead athletes have a much higher likelihood of impingement. Even with correct form for pitching or serves in tennis, the stress is still high. Professional athletes frequently subject themselves to predictable injury because of their drive to compete.

This blog post also does a reasonable job of discussing it.

To produce the same strengthening of as an overhead press you can do an upright row and a shoulder shrug. Same muscles, used the same way, but each avoids excess abduction of the humerus.