by Marty Hull

Increasing Flexibility

Great Breaststroke Kick: The Ins & Outs

Legs are very powerful and efficient on land. In the water, legs don't workas well. Even the best swimmers are able to transfer only a small percentageof their leg power to the water efficiently. Slower swimmers transfer evenless.

How Does Kicking Work?

Kicking involves pressing surfaces of the feet against the water at angles that will push us forward. Swimmers who have excellent joint range of motion are able to orient the surfaces of their feet so their kicking movements provide good propulsion. Swimmers with less joint flexibility produce less propulsion from similar movements while exerting equal force. They go slower.

If you improve your joint range of motion, you can:

  1. Increase the effective surface area of the foot so you have more surface to push against the water.
  2. Increase the safety of the movement so you can use higher muscle force without worrying about causing groin or knee damage.
  3. Increase the distance that the foot travels in each propulsive movement so the foot surfaces can push against the water for a longer period of time.
  4. Keep the foot surface more effectively oriented throughout the kicking movement so each kicking movement produces more propulsion.

All of the above can be accomplished safely if you learn about and carefully do stretching exercises to increase range of motion in the feet, lower leg and hips, and supplement these with strengthening exercises to allow faster, more powerful movements. We start with some definitions.

A. Leg Adduction: The drawing to-gether of the legs by contraction of the adductor muscles. A major aspect of the breaststroke kick.

B. Leg Extension: The straightening of the leg at the knee by contraction of the quadriceps muscle. The most powerful movement in the body.

C. Medial Rotation of the Leg: The rolling inward of the knee by a contraction of the groin muscles. If the leg is bent at the knee, medial rotation of the upper leg rotates the lower leg and foot out to the side. Seeillustration 1.

D. Lateral Rotation of the Foot: When sitting in a chair with the feet onthe floor, the right foot rotates clockwise around an axis running through the knee and the heel. The left foot rotates counterclockwise. SeeIllustration 2.

Increased Foot Surface Area

Most swimmers use the surfaces on the inside of the foot and inside of the lower leg to transfer power to the water when doing breaststroke kick. Youcan further increase the useable foot surface area by rolling the outsideedge of the foot over and pushing on the water with the underside of thefoot. To do this, you must be able to roll your foot over as demonstrated in photo 1.

Stretch 1. To stretch the foot, sit in a chair, grab your foot firmly withboth hands and twist the foot as shown in photo 2. Apply moderate force forone to one and a half minutes. Stretch both feet two or three times.Gradually increase force levels over a period of several weeks.

To strengthen this movement, forcefully contract the muscles that roll overthe outside edge of the foot. Hold the contraction for three to four secondsand then relax the muscles. Do this 10 to 15 times with each foot. Do thesestretches and strengthening exercises three to five times per week.

Safer Kicking

Butterfly kick and flutter kick are very safe movements. We can do thesekicks as hard as we want to without injury. The breaststroke kick powermovement is a combination of adduction (drawing together) and extension(straightening) of the legs. For most swimmers, the adduction component makesa larger contribution than the extension component. Leg adduction places great stresses on the groin and on the inside of the knee and is the sourceof most injuries in breaststroke. Most swimmers do not have access to an effective alternative movement so they must use an adduction-basedbreaststroke kick and intuitively control muscle force levels to avoid injury.

If we change the mechanics of the kick_increasing the leg extensioncomponent and decreasing the adduction component the breaststroke kick becomes, in essence, a straightening of the leg. This is a safer and much more powerful movement. These changes also allow the foot to move along a slightly longer path. When more force is applied along a greater distance,the result is more distance per kick.

To make these changes, both hip joints must be stretched to allow more medial rotation.

Stretch 2. Medial rotation: Stand on your left leg. Support yourself with your left hand. Bend the right leg at the knee and pull the knee forward.Reach the hand over the foot and grasp the instep.

Firmly hold the foot in this position as shown in photo 3. Look at this picture very carefully and have someone else compare your position with the picture so you do the stretch safely and correctly. To stretch, move or press the knee back. The farther you move the knee back, the more you will stretch the area. (See photo 4.) Maintain pressure for one to 1-1/2 minutes. Use light pressure at first. After you become familiar with the stretch, use moreforce for longer. Do each leg three to four times per week. Done correctly, this stretch will forcefully rotate the upper leg at the hip joint, increasing hip range of motion without stressing the knee joint.

Strengthening Exercises

To strengthen this movement, stand on your left foot, bend the right leg atthe knee so the right foot is behind you. Attach a thick piece of surgical tubing to the wall to your left. Run the tubing behind your left leg and loopit over your right foot (See illustration 1). To exercise, keep the right knee stationary and rotate the upper leg medially. This will rotate the lowerleg and foot counterclockwise against the resistance of the tubing. Exercise both legs. Do in sets of 30 to 50 repetitions three to five times per week.As strengthening occurs, increase size of tubing or distance from tubing.

All Solved? Not Yet!

The medial rotation of the leg causes the feet to rotate inward. At this orientation, the foot surfaces no longer effectively engage the water. More adjustments are necessary. The lower leg must be stretched to allow the foot to rotate out farther. Then it works.

Stretch 3. Lower leg outward rotation: Sit in a chair, reach the right armunder the left leg and then grasp the instep of the foot with the hand, asshown in the pictures (Photos 5 & 6). To stretch, press the right elbow forward and pull the right hand back. This causes the foot to rotate outwardand stretches the structures in the lower leg. Stretch each leg for one to1-1/2 minutes three to four times per week.

Caution: This is an extremely powerful stretch. The arm works as a very powerful lever to rotate the foot. If you push too hard, you may severely damage your knee, so be very careful.

If you begin with light forces, and carefully increase force levels over a period of several months, the knee joint apparatus will gradually strengthen.As this occurs, you will be able to safely increase force. The structures of the lower leg will stretch and greater outward foot rotation will be possible.

Strengthen this outward rotation movement by sitting in a chair with your feet on the floor. Forcefully contract the muscles that rotate the feet outward. Hold the contraction for three to four seconds. Do this 20 to 30 times, several times per week.

Now Just Add Water

Begin by doing some breaststroke kicking on your back. When you recover the legs, keep the knees about an inch apart and do not allow them to break the surface of the water. This will force you to recover the legs correctly. (Seeillustrations 3-6). From this position, rotate the feet outward so they engage the water. As they engage, begin to straighten the legs (start thekick). As the legs begin to straighten, medially rotate the legs (roll both knees inward). This causes the feet to sweep out along a longer path. Watch the kick as you are doing it. Did you do it?

Once you are able to get the feet to sweep out a little wider, try to rollover the outside edge of the foot to engage the water with the bottom of the foot. If you feel water pressure on the bottom of your foot, you are doing itcorrectly.

After you perfect this drill on your back, try doing some kicking on yourfront. Remember to keep the knees closely together, approximately the same width as your hips, and try to get the feet to sweep out wider than the knees. Don't use a kickboard. Use a small, hand sculling movement to support your front end. Then try swimming.

These stretches and exercises will eventually allow you to use positions and movements to which you formerly did not have access. It will take time. Youmay become frustrated. Keep working on the stretches and as range of motion increases, your movements will gradually begin to change because this is whatyou look for: a more efficient way to swim.

Marty Hull is a top Masters swimmer and a consultant to the Stanford University Swim Team.

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