Freestyle Pulling Motion: Correcting the In Sweep
In the freestyle pull, because of the anatomy of the shoulder joint, there will always be some in sweep of the hand as it moves backward past the shoulder. The question is how much should the hand in sweep?
We know that whenever the hand turns inward or outward during the pull, the forces get directed more in or out and less backward. As a result of this increase in lateral force, swimmers lose propulsion. The answer to the above question should be in sweep with the hand as little as possible, with the hand passing just barely under the edge of the body. We often see swimmers’ hands pass way under the body during the pull, particularly when taking a breath to the opposite side.
When we tested Olympian Artyom Machekin using Smart Paddle technology, we compared the lateral forces from an exaggerated in-sweeping motion with the lateral forces from his normal freestyle sprint technique. We found that his lateral inward forces were almost exactly the same with either technique. In other words, he is in-sweeping too much with his normal technique and more with his left hand than with his right hand.
Except for a couple of strokes, Artyom’s in sweep is stronger with his left hand (yellow peaks above the zero line above)
With his normal sprint technique, just past his shoulder, Artyom begins a big in sweep with the left hand, causing an increase in his lateral force (graph above right red curve at green line) and a drop in his propulsive force (graph below red curve at green line)
The propulsive impulse represents the propulsion generated by the swimmer through the entire pull of each stroke. It is an indication of how well the swimmer ‘holds water’ during the pull. While the peak propulsion is consistently higher for Artyom’s left arm, because he in-sweeps more with that hand, the impulse is not much greater for the left arm compared to the right arm
When working on their freestyle pulling motion, swimmers should try to not allow either pulling hand to sweep very far beneath their body line, particularly on the breath stroke. Doing so leads to a loss of propulsion and swimming speed. It may also increase the risk of shoulder injury.
Yours in Swimming,