Swimming Technology Research

 

 

FAQs from our swimming technique clinics

 

 

These are questions frequently asked at our clinics with Dr. Havriluk's answers.

 

How do swimmers with obvious technique problems still swim very fast?

Fast swimming is determined by a number of factors - physiological, psychological, biomechanical, etc. A swimmer may be so gifted in one attribute (e.g. strength, lung function, pain tolerance) that it offsets his/her technique limitations. A swimmer with a high maximum oxygen uptake (75 ml/kg/min) or a high peak hand force (60 lbs) can have substantial technique limitations and still swim very fast.

 

Which fast swimmer has perfect technique?

Faster swimmers have more effective technique than slower swimmers. (See Havriluk, 2003) However, even the fastest swimmers have limiting factors. (See Havriluk, 2006a) If you copy the technique of an Olympian, you risk adopting their limiting factors as well as their positive technique elements.

 

What about the __________(characteristic technique element) of __________(Olympic champion)?
A characteristic technique element of an Olympian may be obvious, but not necessarily helping him/her swim faster. It's vital to differentiate between characteristic technique and effective technique, especially in Olympians.

 

What is the most important factor in swimming propulsion?
Hand force is the single most important factor in swimming propulsion. It is directly related to swimming speed. If you increase your hand force, you will swim faster. (See Havriluk, 2004)

 

How do you increase hand force?

Most swimmers can increase hand force by increasing the hand speed throughout the stroke cycle. Bilateral symmetry is necessary to maximize hand force. (See Havriluk, 2007b) Avoiding wasted motion and force losses will also increase total force on each stroke. (See Havriluk, 2006a)

 

How do hand force values vary within a stroke cycle?
The arm can move into stronger and stronger positions at faster and faster speeds throughout the stroke cycle. Hand force peaks about halfway into the push phase (after the arm passes the shoulders) for freestyle, butterfly and backstroke. The force value on the push phase is typically twice as much as on the pull phase. (See Havriluk, 2008)

 

What is the most important part of the freestyle stroke?
The entire stroke cycle is important. Most swimmers don't take full advantage of the push phase because the arm exits prematurely. Maintaining the elbow below the surface can increase hand force on the push. A swimmer who does not double the force from the pull to the push has a major technique limitation. (See Havriluk, 2008)

 

What causes shoulder injuries?

Three contributing factors to shoulder injuries are: overuse (excessive training distance), ineffective technique, and inadequate strength training. Any single factor can cause injury, but a combination is often responsible. A decrease in training distance, a change in technique to decrease stress on the shoulder, and strength training that targets muscular imbalances are all necessary to recover from a shoulder injury. (See Becker & Havriluk, 2006 and Stroke Test)

 

Can hip rotation increase hand force in freestyle?

No. In freestyle, the torso rotates about the polar axis (a reference axis through the center of the body from head to feet). The arm motion is perpendicular to the torso rotation and the hand force cannot be increased by the force of hip rotation. Summation of forces (See Chapter 4) requires that successive body segments (torso, upper arm, lower arm, hand) rotate in the same direction (as in throwing). Although the timing of the push phase in freestyle is usually simultaneous with torso rotation, rotating the hips harder or faster will not increase hand force.

 

When is gliding recommended?

It is appropriate to glide when the body is moving faster than swimming speed. For example, when the body enters the water after a start or leaves the wall after a turn, it is moving faster than swimming speed and gliding is appropriate. There is one other time when gliding may be appropriate. During breaststroke, for a fraction of a second after the kick, the body may be moving faster than swimming speed. When this is the case, it is counterproductive to immediately begin the arm motion.

 

Is there a glide phase in freestyle?

No. Gliding in freestyle (usually associated with "catch-up stroke") is counterproductive. During a glide phase, there is no propulsion from either hand. The body slows down and requires considerable energy to speed up. The energy cost of speeding up on every stroke is greater than maintaining a relatively constant speed. Gliding in freestyle is biomechanically ineffective, physiologically inefficient, and anatomically stressful. (See Havriluk, 2007, page 5)

 

What is the most important factor in swimming resistance?

Reducing the body cross-section (the area perpendicular to the direction of body motion) is the most important factor in swimming resistance. Keeping the hips and legs directly behind the shoulders minimizes the cross-section. (See Havriluk, 2005)

 

What's the best measure of swimming technique?

Counting strokes is the easiest way to measure technique, but not the best. A decrease in stroke count does not always indicate a more effective technique. An increase in stroke count does not always indicate a less effective technique. The active drag coefficient is the most accurate measure of swimming technique. (See Havriluk, 2003; Havriluk, 2006b; and Havriluk, 2007a)

 

What's the best way to control technique changes?
Skills must be learned at a slow swimming speed. Once a swimmer has learned to control his/her movements at a slow speed, gradually increasing the stroke rate will help a swimmer maintain control at faster speeds. Individual instructional sessions and regular analysis sessions expedite the learning process. (See Havriluk, 2006b and Havriluk, 2007c)

 

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