Flexibility is a huge part of a swimmer’s ability. In freestyle, backstroke and fly, there are two joints that require extraordinary flexibility in order to excel, the shoulders (particularly extension) and plantar flexion of the ankle. Obviously, the former helps in the pulling motion and recovery, while the latter helps in the kicking speed.
In breaststroke, the two most important areas of mobility are in the lower (lumbar) spine and the hip, particularly with external rotation. A flexible lower back enables the swimmer to elevate higher during the pulling motion and create more coupling energy both for the pull and the following breaststroke kick. The external rotation of the hip enables a swimmer to create more surface area of the instep during the propulsion of the kicking motion.
At The Race Club we often say that swimming is a sport of tenths of seconds, millimeters and degrees. What is meant by that is that there is a small margin of error between getting it right or not. There is neither a lot of forgiveness nor mercy in the water. Breaststroke kick is a good example of that.
For every additional degree of external rotation in the hip, I would estimate that the propulsion from the kick increases by 5 -10 %. In other words, if one were to increase the external rotation of the hip by 5 degrees, one would achieve 25 to 50% more propulsive force with the same amount of effort, just by increasing the surface area of the instep pushing backward. To me, that seems worth fighting for.
There are two very simple tests to evaluate your swimmers’ mobility and potential to kick breaststroke fast. The first is the hip test. Have the swimmer sit on a chair or bench and cross the legs with one ankle on top of the thigh of the other leg. Flex the foot of the bent leg to protect the knee. Then, with arms stretched straight overhead, have the swimmer bend forward at the waist with a straight back, allowing the arms and hands to fall toward the ground. A good breaststroker (or at least potentially) will be able to put the palms of their hands all the way to the ground. A swimmer with limited external rotation in the hip will not even come close.
For those with limited hip flexibility, the same stretch can be used daily, holding the position for a minute or longer on each side, in order to improve the breaststroke kicking propulsion. There are many modifications of this hip stretch and just like in swimming technique, some work better based on the individual. When I was at Indiana University, I was an IMer with a very poor breaststroke (an extinct breed of IMer). My coach, Doc Counsilman, had me walk around for hours with what he called ‘alligator shoes’ on. These were a pair of high top Converse All-Stars nailed to a board angled at 45 degrees to the ground. The hope was to increase my ankle dorsi-flexion by lengthening the gastrocnemius muscle and tendon (calf and Achilles tendon). Unfortunately, that is like stretching a Trans-Atlantic cable….and I never did get much faster. We were just focused on the wrong place. The hip, which is a ball and socket joint, is a much easier place to increase mobility than stretching the Achilles tendon and gastrocnemius muscle.
The other test I use for breaststroke is to evaluate the flexibility of the lower back. First allow a proper warm up to loosen the low back and strengthen the core. Then, hold down the ankles of a prone swimmer and have them arch upwards with the upper body as far as they can. Olympian Rebecca Soni, can bend her body to nearly a 90 degree angle. Or one can do a back pushup, which requires considerable spinal flexibility and arm strength. The closer the swimmer can bring their hands toward the feet on the ground, the more flexibility is present in the lower back. There are modifications to begin increasing low back flexibility to slowly work up to these back bending exercises.
A strong kick is a key to swim fast breaststroke. As much as 80% of a swimmer’s propulsion in breaststroke comes from the kick. The power of the kick depends on having a large surface area of the instep accelerating quickly backward, coupled with the energy of the upper body pressing forward and the head snapping downward. To do well, both motions require extraordinary flexibility in the back and hip, plus strong legs and core.
Do these two simple mobility tests for each of your swimmers. If your swimmers don’t have enough hip mobility, either develop a stretching/dryland program whereby they can develop more, or don’t focus on the IM or breaststroke. Either option is acceptable. Just don’t expect them to swim fast breaststroke without having this type of flexibility.
Yours in swimming,