The front crawl, sometimes called the freestyle, is the fastest stroke. When performing this stroke, your body is prone and straight. The front crawl uses much body roll. Body roll is a rotating movement around the midline, an imaginary line from head to feet that divides the body equally into left and right parts. With body roll, the whole body rotates, not just the shoulders.
It results from three movements: (1) the high recovery of one arm, (2) the downsweep of the other arm, and (3) the sideways force of the kicks as the legs roll with the rest of the body.
Body roll is important for almost all aspects of the front crawl. It helps you use a relaxed and high elbow recovery and improves arm propulsion. Body roll helps you breathe rhythmically and keep an overall rhythm in your stroke.
Your head position is an important part of overall body position. Most swimmers keep the water line between the eyebrows and hairline, depending on their buoyancy. Someone with little buoyancy may have to lower the head a little to raise the hips to best level.
Head movement is critical and it is commonly said, “where the head goes, the body follow.” If your head moves from side to side, as often happens, your body will move laterally. If your head bobs up and down, your hips will do the same. In both cases, the resulting body motion slows you down.
Finally, your legs also affect body position. Poor body position can cause a poor kick, and a poor kick can cause poor body position. In a correct kick, your heels just break the surface of the water. Your legs roll with the rest of your body.
To begin the power phase, your hand enters the water in front of your shoulder, index finger first. Since you keep the elbow partly flexed, the point of entry is about ¾ as far as you could reach with your arm straight. Use a smooth entry, with your elbow higher than the rest of your arm and entering the water last. Your hand is angled out and down as you extend your arm fully under water to start the catch. It is called the catch because you feel as if you have grabbed a semi solid mass of water and are about to push it.
The power phase (S – shaped pattern) starts with the catch. With your arm extending and your wrist slightly flexed, you sweep you hand down and slightly out to just outside the shoulder (top of the S shape). If the arm made a good entry, your elbow will be higher than your hand at the start of the pull and will stay higher throughout. The catch feels like a natural motion to make to move forward. It happens automatically if you hand is pitched correctly and you let your shoulder roll properly. You feel tension in your wrist and pressure on your palm.
As the power phase continues, your elbow bends to a maximum of 90 degrees and your hand and arm sweep back toward your feet and up toward your chest. (This is the diagonal part of the S shape) Your hand should not cross the midline of your body. In this sweep, pitch your hand in instead of out and keep your wrist nearly flat. This is the deepest point of the stroke (the end of the catch or S shape pattern)
The recovery puts your hand in a position to pull again. The most important point is that the recovery should be relaxed. While your arm recovers to the starting position, its muscles can rest. If you do not let your arm, hand and fingers relax, they do not benefit from this brief rest, and you will tire more quickly.
Make a smooth transition from the finish of the power phase to the beginning of the recovery. In the recovery, lift your elbow high out of the water. Turn your palm toward you leg so that your nad exits the water little finger first. Your body roll is at it’s maximum. Lift your elbow high and relax your arm with the forearm hanging down. As your hand passes your shoulder, let it lead the rest of your arm until it enters the water. Your arms at this point are not completely opposite each other. Instead, the recovering arm starts to catch up with the stroking arm.
Most swimmers breathe each arm cycle (e.g., each time their right arm recovers) or every 1 ½ arm cycles (alternating side on which they breathe). Either method is correct, although most people learn this stroke by breathing every cycle. Coordinate your breathing so that you do not pause in the stroke to breathe. You do not need to inhale a large amount of air with each breath because the next breath is coming soon.
Start turning your head to the side as that arm starts its pull. Your mouth clears the water at the end of the pull, and you in hale just as the recovery starts. Body roll makes it easier to turn your head to the side. Look to the side and slightly higher than your chin. The opposite ear stays in the water. In this way you breathe in a trough made by your head as it moves through the water. After inhaling, return your face to the water.
Proper head motion for breathing lets you keep your head low in the water, which helps you keep good body position. Return your face to the water as you move your arm forward. Exhale slowly through your mouth and nose between breaths. Exhale completely underwater so you are ready to inhale at the next breath.
The propulsion from the kick (called a flutter kick) is less than from the arms, but the kick is still important. In fact, without a good kick you won’t have proper stroke mechanics.
The way you hold your ankles is essential in this kick. They must be relaxed and “floppy” to be effective. Even if you have perfect mechanics, the kick will be ineffective if your ankles are either still (with toes pointed) or flexed. On the other hand, if your ankles are loose and relaxed, you have a moderately effective kick even if other aspects of your kick need work.
The power part of the kick is the downbeat. The motion starts at the hip, with your thigh starting downward even while your calf and food are still moving upward. For most of the downbeat, keep your knee slightly flexed.
The propulsion occurs when you straighten your leg. This motion continues through the whole leg, and the feet follow through. The feet are turned slightly inward (pigeon-toed). Your food snaps downward, completing the motion, as though you were kicking a ball.
In the upbeat (recovery), raise your leg straight toward the surface with little or no flexion in your knee, until heel just breaks the surface. A common error is to bend the knee and thus pull the heel toward the buttocks. Your leg must stay straight in the recovery. Your knee is flexed for most of the power phase, and extends forcefully at the end of the kick.
The size of the flutter kick, the distance the leg moves up and down, is not great. Depending on how tall you are, it ranges from about 12 to 15 inches.
Information taken from “The American National Red Cross – Swimming & Diving” 2004