dolphin kick

There are a number of aspects of the dolphin kick that I'm still unsettled about. Firstly, it seems to me that the underwater dolphin kicking one does off the wall is different from the full body dolphin motion one does during full stroke butterfly. Watching underwater dolphin kicking at the start and turns it is pretty clear it is not initiated at the shoulder or chest. The frequency of the off the wall dolphin kick is also far higher than one could possibly using during surface butterfly. I can't remember the exact source but I am sure I've read that the actual transmission of force via a wave down the body is very small, unlike a wave moving down a towel as you whip it your body is moving through water where the resistance forces are much larger. It seems to me that it would be more accurate to describe the wave motion as following an arc that minimizes resistance than to describe it as a propolsive movement driving the legs. I am also not comfortable with an explanation of dolphin kicking that can only apply to one-kick butterfly. In a two kick style the upper body and lower body are moving with two different frequencies. Not only that, but if you watch a one kick style swimmer like Thorpe or Esposito the timing of the kick does not fit the wave moving down the body model. When I observe underwater butterfly video I see a downward movement of the chest and legs which raises the hips. This is common to one kick or two kick butterfly, the basic difference between the two is that in one kick style the swimmer simply drags their body and legs during the pull while the two kick swimmer does a dolphin kick during the pull. It is this second kick which follows the moving wave model. The other thing I find problematic with the snake moving through the water analogy is the inability of the human lower body to bend in both directions (i.e. the knees only bend in one direction).

There are a number of aspects of the dolphin kick that I'm still unsettled about. Firstly, it seems to me that the underwater dolphin kicking one does off the wall is different from the full body dolphin motion one does during full stroke butterfly. Watching underwater dolphin kicking at the start and turns it is pretty clear it is not initiated at the shoulder or chest. The frequency of the off the wall dolphin kick is also far higher than one could possibly using during surface butterfly. I can't remember the exact source but I am sure I've read that the actual transmission of force via a wave down the body is very small, unlike a wave moving down a towel as you whip it your body is moving through water where the resistance forces are much larger. It seems to me that it would be more accurate to describe the wave motion as following an arc that minimizes resistance than to describe it as a propolsive movement driving the legs. I am also not comfortable with an explanation of dolphin kicking that can only apply to one-kick butterfly. In a two kick style the upper body and lower body are moving with two different frequencies. Not only that, but if you watch a one kick style swimmer like Thorpe or Esposito the timing of the kick does not fit the wave moving down the body model. When I observe underwater butterfly video I see a downward movement of the chest and legs which raises the hips. This is common to one kick or two kick butterfly, the basic difference between the two is that in one kick style the swimmer simply drags their body and legs during the pull while the two kick swimmer does a dolphin kick during the pull. It is this second kick which follows the moving wave model. The other thing I find problematic with the snake moving through the water analogy is the inability of the human lower body to bend in both directions (i.e. the knees only bend in one direction).