This is internal shoulder rotation and should be avoided in any sport
Internal shoulder rotation causes shoulder impingement injuries
Finish any reaching, throwing, or hitting motion with your hand little finger down
For swimmers this means:
FREESTYLE
Hands are vertical, little finger down, throughout the stroke. Hands and forearms are close to your long-axis throughout the stroke. This keeps your shoulders in a natural position.
Do not rotate your arm down and under your body. This is also internal shoulder rotation. This forces your shoulder into an unnatural position.
Freestyle is an arms in front of you stroke, not an arms under you stroke.
BACKSTROKE
Thumb leads the recovery, hands enter the water vertical, thumb first, close to your long-axis. This keeps your shoulders in a natural position. Then rotate your hips vertical as you set the catch, hand horizontal, little finger down.
BUTTERFLY
Hands exit the water little finger first. Palms lead the low recovery. Hands enter the water vertical, little finger first, not thumb first.
This keeps your shoulders in a natural position. Of all the strokes, butterfly has the most potential for shoulder injury, so swim fly this way.
Hands enter the water vertical, little finger first.
• Internal shoulder rotation, anywhere in any stroke, is harmful.
• It causes shoulder impingement injuries (rotator cuff tendinitis or shoulder bursitis).
• Keep your shoulders in a natural position.
Many swimmers rotate their arms not their hips, which is a mistake
