Thứ Hai, 15 tháng 8, 2016

leg kick in the freestyle stroke

triathletes - you're not looking for propulsion
Our swimming animation Mr Smooth demonstrates an effective 6-beat kick. Kick from the hip with a relatively straight leg.
Here at Swim Smooth we have a different viewpoint on kicking for amateur swimmers and triathletes.
This may come as a surprise, but you're not looking to get much or any propulsion from your leg kick. Elite freestyle swimmers with world class kicks only get a small fraction of their propulsion from their legs (about 10-15%). Most triathletes and amateur swimmers get next to no propulsion from their kick.
Our conclusion is that you shouldn't be looking to get propulsion from your kick. For most triathletes it's simply not realistic.
so, i ignore my kick?
No, far from it. You still need to work on your kick technique. That's because there's more to kicking than propulsion, you still need an 'effective' kick. What does 'effective kick' mean? :
- Your kick should lift your legs up to give you a good body position.
- Your kick should be low drag.
- Your kick timing should drive your rotation, not hinder it.
- Your kick should be low effort so it minimises energy use.
Most triathletes don't have effective kick technique. Making your kick more effective will reduce the effort required to swim and boost your speed by reducing your drag.
what will give me an effective kick? there are 4 key technique elements:
1. Kick from the hip
Many swimmers bend their knees too much whilst kicking - we call this kicking from the knee. This creates large amounts of drag and is probably the number one reason for a swimmer's legs to sink low in the water. Instead of kicking from the knee you should kick from the hip with a relatively straight leg. See the animated clips:
Don't: Kick from the knee, it creates loads of drag.
Do: Kick from the hip with a relatively straight leg.
Triathletes can have a real problem here. Cycling and running involve developing power from the knee and it's easy to carry this habit across into the water. As soon as you bend your knee you present your thigh as a blunt object to the water and you push the water against the flow.

Kicking from the knee is very naughty.
With good kicking technique, you can bend your knee a little on the down stroke but this shouldn't be a ‘driven' movement, it's just a slight movement from a relaxed knee. As described in the tips below it's best not to think about bending your knee at all, instead think about kicking from the hip with a straight leg – a very slight knee bend will happen naturally.
2. Plantar flexed feet (Pointing Your Toes)
Plantar flexion is technical jargon for pointing your toes. When you swim you should always have your toes pointed, this presents a much lower profile to the water. Not pointing your toes will push water forwards when you kick, slowing you dramatically.
Dorsi Flexed Feet
Dorsi Flexion - bad technique and instant loss of speed.
3. Ankle Flexibility

A flexible foot that can bend beyond straight. Great for kicking with. Mmmmm.
Many triathletes have poor ankle flexibility limiting how much they can point their toes. In an ideal world you want to be able to flex your feet beyond straight.
If you have a background in cycling or running (especially running) then you're likely to have stiff ankles such that you can't achieve a straight foot. This will be hurting your kick technique and slowing you down when you swim. See our tips below to develop a bit more flexibility in your feet.
The video of Charles below shows the amount of flexibility in elite swimmers' ankles.
Charles has very flexible elite-swimmer's ankles. As a triathlete you don't need feet this flexible, it could lead to running injury.
Becoming as flexible as Charles is not advisable for triathletes as it reduces ankle stability which can lead to running injuries. However, improving your ankle flexibility a little so you can point your foot straight is achievable. It's very desirable because it will reduce your drag and you'll slip through the water much faster.
4. Timing
The timing of the kick is something that we don't normally think about much as swimmers. We have a variety of kicking speeds open to us as we'll describe below – 2, 4 or 6 beats. The key to good timing is that when the hand enters the water at the front of the stroke, the opposite leg should kick. In 2 beat kick this is the only kick, in 4 and 6 beats there are other kicks in between but the kick on opposite hand entry is the important one for timing.
If your timing is wrong you won't be helping your body rotationwith your kick – you could even be counteracting it. For more information on this important swimming technique, see the Advanced Level Mr Smooth Presentation.
Most swimmers kick with the correct timing naturally, unless you know you have a problem don't be too concerned about timing – focus instead on pointing your toes and kicking from the hip, this is much more likely to be holding you back.
more about kicking – 2, 4 or 6 beats?
In 2-beat, you kick twice for every cycle (a cycle is 2 arms strokes counting both arms). This is a slow kick speed that many distance swimmers and skilled triathletes use.
Paul demonstrates a 2-beat leg kick.
A 6-beat kick is 6 kicks per cycle. This is a traditional flutter kick technique that most swimmers use. The power in the kick can be varied dramatically, you can use a very light flutter to distance swim economically or increase the power dramatically to sprint.
Paul demonstrates a 6-beat leg kick.
The 4 beat kick is a hybrid that some swimmers employ. It tends to happen naturally for some swimmers doing 'just what feels right for them'.
Which kick technique should you use? For novices and most intermediates we suggest you do whatever comes naturally and not be too concerned with the kick speed. For you it's more productive to focus on kicking from the hip and pointing your toes than worrying about timing and how many beats you are using. Don't try and change your natural kick speed until you are sure you a kicking from the hip and pointing your toes.
For strong intermediates and advanced swimmers you can experiment with different timing to see what suits you best. For distance swimming and triathlon a 2 beat kick is the most energy efficient once the frantic swim start has died down. However, a 2 beat kick is not for everyone, many women and shorter men find it hard to make a 2 beat kick technique work for them – it just feels too slow. If a 2 beat kick doesn't feel right for you, don't try and change to one.
A two beat kick is particularly suited to the Swinger Swim Type. Our Development Guide for Swingers includes the techniques and drills you require to develop your two beat style.
scissor kicks
scissor kick
Scissor kicks, cut them out and you'll go a *hole* lot faster. (Taxi for SS!)
A scissor kick is a very large opening of the legs, normally when a swimmer goes to take a breath.
They hurt you because of the enormous amount of drag they generate – it's a bit like opening up a parachute behind you.
Scissor kicks normally come about in your stroke technique due to a problem with your balance in the water. We're land mammals and it's instinctive for us to move our legs and feet to keep our balance. We do the same thing in the water - scissor kicks are a natural unconscious reaction to keep your balance in the water, most of the time swimmers don't even know they're doing it.
Note. Some Scissor Kicks come about when a swimmer is trying to developan overly long stroke.
An overly long stroke is one that's too long and slow. Because the swimmer's stroke rate is so slow there's a long time between strokes which makes it hard to balance in the water.
This balancing act often causes scissor kicks. For these swimmers, increasing their stroke rate (ideally with a Wetronome) often removes the scissor kick – even if they didn't know they had one!
See an example of this when Simon uses a
Wetronome
.
our 4 top tips to develop an effective kick technique
1. Stretch Your Ankles
If you feel you have stiff ankles, you can perform some gentle ankle stretches to improve your flexibility. Do not force these. Do them little and often and gradually your flexibility will increase.
Perhaps the best way to stretch your ankles is to use fins (flippers) regularly. They force you into using a plantar flexed (pointed toes) position and provide some stretching force to your ankles. Over a period of time they will develop and maintain your ankle flexibility.
You can use fins for kick sets, drills and the occasional fast swimming set. You don't want to use them too much but wearing them little and often will improve your kick by stretching your ankles.
If you are buying fins, we recommend you get something mid-length and floppy, like these Finis Floating Fins.
ankle stretch
Progressively stretch your ankles over many months. Treat it as a long term project, developing some flexibility little by little.
2. Point your toes whilst you swim
Simple really, focus on holding your foot gently pointed whilst you swim. This should be a gentle hold, your foot and calf should be mostly relaxed or you risk cramp and muscle ache.
3. Kick from your hips
A good way to think about kicking from your hips is to squeeze your bum when you kick. It's a bit crude, but imagine you have a large coin between your butt cheeks and you're trying to hold it there whilst you swim. Keep your knees relaxed and drive the kick from the hips.
4. Use the Kick Off The Wall Drill
Use the kick off the wall drill to develop your kick technique.
Use this technique to re-program your kicking action:
Simply perform a torpedo push off from the wall but keep your arms out in front of you and your face in the water, kicking vigorously for about 15m or until you run out of air. Then stop and swim gently back to the wall.
When you are kicking off the wall you need to focus on the following things:
1) Point your toes as in tip 2.
2) Kick from the hip as in tip 3. Focus on your imaginary coin and keep your knees relaxed.
3) Point your toes slightly inwards so that your big toes almost brush together.

Perform this drill 3 or 4 times in a row, kicking vigorously off the wall focusing on those three things. Then try a lap of steady freestyle swimming – not thinking too much about your kicking technique except just tapping your big toes lightly together. You should find that the kicking action you've just tried sticks for a while. Remember, you're not looking to feel extra propulsion, you're looking to feel higher in the water with less drag – a sensation of slipping through the water with less effort. If you're used to kicking hard this will feel very easy.
Resource: swimsmooth.com

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