Heavy side laterals tend to overstimulate the supraspinatus muscle.
A hypetrophied supraspinatus will reduce the amount of space directly beneath the acromion and above the shoulder joint ( subacromial space. )
The muscle will rub against the acromion, resulting in inflammation, swelling and, in the long term, muscle tear
The symptoms generally include a sharp pain, deep inside the trapezius muscle.

