1. Crossing the midline of the body on entry
The swimmer is entering their left arm into the water and crossing an imaginary midline of the body. Most swimmers who do this do not even realize it. Those who cross the midline of the body upon entry risk shoulder injury and are less efficient.
2. Elbow dropping on entry
The swimmer is seen with the elbow dropping well below the wrist
The fix: Swimmers should think about aiming deeper into the water rather than for the surface. Fingertips should always be below the wrist, wrist below the elbow, and elbow below the shoulder. Also, be sure not to over-rotate which drops the shoulder too deep into the water and can cause the hand to rise above the elbow.
3. Windmill the arms
The swimmer is seen starting the pull too soon and their arms are moving exactly opposite of each other like a fan or a windmill. The fix: The catch-up drill is great for fixing this mistake. It
The swimmer should practice keeping one arm straight out in streamline until the other hand catches up to meet it before initiating the next stroke. The catch-up drill can also be done as a one-arm-only drill where the swimmer keeps one arm stationary in streamline and uses only the other to swim across the pool.
4. Pushing the water to the side
The swimmer in this picture is entering the water then internally rotating their arm to push the water to the side instead of pulling it back. Fingertips should enter reaching straight ahead in streamline with the palm facing down. Then, the fingers should point directly to the bottom of the pool as the elbow bends in the catch and pull phases of the stroke.
The fix: The swimmer should imagine pulling themselves to move in front of the water rather than pushing the water behind them. In other words, imagine your hand, with fingers to the floor, anchored into place while you engage your back muscles to hurl the body in front of the hand. This will yield stronger, faster results than using weaker arm and shoulder muscles to push the water back.
5. No early vertical forearm
This swimmer has a straight, long arm during the pull phase of the stroke as though he is reaching for the bottom of the pool. This slows the swimmer by creating drag. In addition, the swimmer is missing out on power generated by using strong muscles in the back.
The fix: Imagine swimming in very shallow water with lots of seaweed at the bottom. If you don’t want to touch the seaweed, you need to bend the elbows at 90 degrees. Do this early in the stroke for a stronger pull. In other words, maintain an early vertical forearm.