Butterfly Kick
The dolphin kick is the fastest way to swim from point A to point B, but with great velocity comes great difficulty. Many novice swimmers are incapable of performing this motion for several reasons. This article will discuss the proper movement of the dolphin kick, most common limiting factors seen in swimmers, most notably Master's swimmers and simple steps to improve dolphin kick.
The dolphin kick has an interesting history as butterfly is the youngest of all the strokes dating back to the 1930s. The butterfly arm motion started when a few swimmers realized this of passive recovery through the air was superior to recovering the arms through the water. At this time the butterfly kick developed, but the potential of the kick was not utilized until the 90s when a few Olympians began swimming whole laps underwater. This form of swimming so quick FINA had to adjust the rules (similar to any issues facing FINA today...)to which they are today, allowing only 15 meters off each wall underwater. This hindered a few athletes, but underwater kicking 15 meters off each wall is still advantageous to swimming the first 15 meters.
The motion of butterfly kick is described as an undulation or mathematically as a sine wave. This motion is initiated in the upper abdominals and thoracic spine. During the upkick, the lower paraspinal muscles contract which extend the thoracic and lumbar spine, posteriorly rotating the pelvis, extending the hips, flexing the knees, and upkicking the feet towards the surface. The down kick is comprised of the opposite motion, contracting the abdominals which flex the thoracic and lumbar spine, anteriorly rotating the pelvic, flexing the hips, extending the knees, and kicking down. This rhythmic motion is done fluidly throughout the entire butterfly stroke, which is a topic for another day.
Many swimmers who have difficulty with the buttefly kick only perform the last two steps, flexing and extending the knee and kicking up and down with the feet. These two steps only generate minimal propulsion in the water. For example if you have a whip which uses only the last 2 inches of an 8 inch whip, the force generated is much lower than if you held the whip from the handle and used the whole damn whip! The most commonly problem I see with swimmers (anecdotal, not researched based) is the lack of hip and pelvis movement. In our society everyone is sitting excessively, computer, television, video games, etc. This increased sitting leads to tightened musculature and immobility. Moreover, we all have poor posture, think as your reading this who isn't hunched over rounding their shoulders with their lower back shoved into the chair. This positioning leads to poor mobility, sometimes pain, and impedes butterfly kick!
As stated, muscular tightness and joint immobility are two factors impeding butterfly kicking skills, but weak muscles and poor muscle timing can cause difficulties with butterfly kick. Each of these areas is independent on the person, but I will depict a few examples with a protocol for them to achieve their butterfly kicking goals.
Example one
"I am a 16 year old male who has been swimming for two years. The reason I started swimming was get a "swimmers body". I am rather strong and athletic since I've been resistance training for the past two years. When I kick, I resort to my favorite resistance training machine, the hamstring curl as I only use my knees to up and down kick." It is likely this swimmer presents with tight hamstrings which are pulling on the pelvis holding it in a posteriorly rotated position. These tight muscles and a lack of pelvis mobility requires a pelvis rocking re-education program. Luckily, this swimmer is young and the muscles are pliable, to help alleviate these problems a stretching program is indicated, focusing on dynamic and isometric stretching of the hamstrings. The resistance training program should focus towards glut strengthening opposed to hamstring strengthen and the main posterior leg exercise should be the Romanian deadlift instead of the hamstring curl.
Example two
"I am a fifty year old female who has decided to start swimming to lose weight following a physical in which the MD recommended an exercise program. Running is too hard on my knees and I've always enjoyed the water. I stated swimming in 2008 after the Olympics....I still can't believe Jake Lezak won the 400 front crawl relay!" It is likely this athlete has a combination of weak glutes and poor timing of her muscles. I would recommend a Resistance training program to strengthen the muscles, but help the athlete gain muscle coordination and ability target specific muscles groups at a time. Similar to the above example, this athlete most likely has poor pelvis and thoracic spine mobility. Since this person works at a desk, it is highly likely they will also have tight hamstrings which can be improved with similar stretching as described earlier.
Pelvis Rocking: poor pelvis mobility-
Lying on your back, this simple procedure is used to help athletes re-educate themselves with pelvis rocking. This maneuver is done on your back and involves arching and flattening your back. This procedure help pelvis tilting forward and backward. This can be advanced to the popular angry cat/purring cat.
Bridges: pelvis anterior tilting and gluteal activation
On your back innate with flattening your lower back and anteriorly tilting your pelvis. With this squeeze your gluteal muscles which mimic the dolphin kick seen in butterfly.
Hamstring stretch for tight hamstrings (note in the video the instructor states to bring your toes up, this will involve a calf stretch NOT a hamstring stretch):
Done in standing, put your leg on top of a small table, 6-12 inches, and bend your your hips forward. This stretch is often done incorrectly and is used to stretch the back, keep your back straight and hitch from your hips!
These are the most common areas to be addressed in the beginner swimmer, take the steps outside of the pool to enhance your potential in the pool, because if you can do it outside the pool it is more likely to translate into the pool!