The technique for freestyle kick and backstroke kick is based on very similar mechanical principals for each of these strokes.
Key points for both kicks are as follows:
• The legs are extended.
• Significant plantar flexion of the feet is an advantage in generating propulsion.
• The leg swings from the hip.
• The muscle contractions which drive the leg movements have their origin in the lower core.
• The amplitude of the kick (as a guide) should be within the margins of the cross-sectional range created by the body.
• The ankles remain loose at all times, so the feet flap up and down like they are hinged.
• Engagement of the gluteus, back muscles, hip extensors and hamstrings during the recovery phase.
• Engagement of the core muscles, abdominals, hip flexors and quads during the extension phase.
• Continuous oscillating action.
• Minimal surface disturbance.
It is vital that children are taught the correct kicking action from a young age. If we come across children who haven’t been taught in such a way then we must address the imperfection immediately.
We need to develop effective kicking in our swimmers not only for propulsion but also for stability or anchoring. The anchoring effect is more related to freestyle and backstroke where we rotate and the kick assists by stabilizing our lower body, this allows our arms through the upper body to apply greater leverage for propulsion.
It must be understood by all that the recovery phase of the kick (upbeat for freestyle and down-beat for backstroke) is performed with a straight knee. When the heel is at the highest point of the kick in freestyle and the lowest point in backstroke, the knee is then flexed and the drive of the power phase of the kick is executed. The leg is rapidly extended during this action.
When the leg completes the power phase the recovery phase begins immediately.
Both phases are propulsive.
When swimmers swim backstroke with their knees breaking the surface it is down to the fact that they haven’t got their legs straight at the knee during the recovery phase of the kick.
Take the time to teach all swimmers to automate the correct mechanics for their kicking technique.