The Propulsion Paradox

[fooboo]

Hm! I think TI and Boomer do it differently at all.

Forums encourage swimmers to be on a side and bury recovery arm
elbow deep, prior to rotating. Boomer recovers and rotates before an
arm even toutches the water. His swimmer angles lower arm till reco-
very arm is still in the air. We (read TI) flow as a water, intenting from the
hip. Boomer throws left-right-left-right-left-right... His hip is connected to
that recovery arm as one single movement.

One of the coaches mentioned that it had no difference if I would use
angled or streight recovery arm. That it is easier to learn with extended.
I do see how I miss that recovery part and would experiment on that this
very morning. Spite discussed zillion times, should one (me) use any
strength during recovery. Now I just let recovery arm be in front. Should
there be any energy during swing? Boomer says: yes.

[Zenturtle]

maybe these little fellows use suction propulsion
https://www.youtube.com/watch?v=9dfWzp7rYR4

[IngeA]

I haven't read all, so I don't know if anyone mentioned this.

I don't think the theory getting momentum by throwing the recovery arm forward does work. Otherwise a rowing boat had to go in the other direction, as the rudders are much faster in the recovery in the air than in the time pulled through the water.
What makes the swimmer in the first video fast is, that he has a good balance and is using by the rotation the big muscles of the torso instead of the weak ones of his arms.
But, on concentrating on the recovery arm and the spearing, the rotation may come more easily and there may be a better connection from the torso to the shoulder girdle and the arms.

[Richardsk]

Hello IngeA

I am not an expert in either physics or hydrodynamics, and for that matter not an expert in the theory or practice of swimming, but it seems to me that any momentum of the oars in a rowing boat while they are being recovered is relatively small and if there is a deceleration effect, which logically I suppose there must be, it is one of those elements that can't be avoided. I suppose some keen student of rowing has studied this. Does anyone know if there is such a study?

I remember reading, I think in one of James 'Doc' Counsilman's books or articles, that one should not try to place the arm gently into the water when swimming backstroke because the momentum of the arm is transferred to the body if the arm is sliced in vigorously. I would be interested to hear what those more knowledgeable than I in physics think about this idea.

[Richardsk]

I found this article, which I haven't read yet, but I think may be relevant to the discussion.

http://eodg.atm.ox.ac.uk/user/dudhia...ics/rowing.pdf

[IngeA]

If you test the same movement with the recovery arm diving under water you will notice, that you will have a deceleration effect because the density of water is higher than of air. It's unlikely, that you have a great deceleration in the diving exercise but a propulsion with the arm in the air. Even in the air it's deceleration, but it's much less.

[CoachStuartMcDougal]

The row boat, or other like vessel - most of the vessel rides above the surface, the oar relative to the weight of the boat is light. When the vessel (our body) is submerged is near weightless, and any part the rides above (recovery arm) will be heavy at the weight of gravity. It's this force (recovery arm) that gains momentum as it's being thrown or driven forward from the weightless hip/pelvis. You will see (and feel) a thrust forward of the vessel as weight swings from the weighted environment to a weightless environment forward of the torso. Coach Boomer carefully characterizes this as "riding the space generated from the moment of the high side arm".

Stuart

[CoachStuartMcDougal]

Originally Posted by Zenturtle

How to establish your aquatic signature? And what are the best swimstrokes for different balance positions?
All I know I am a horizontal floater without any kick in superman.Looking down or 45 degrees forward doesnt matter.
Short legs, longish arms.

ZT: You are very lucky, most of us guys (assuming you are male) hips sink 40-90 degrees; woman more buoyant and closer to horizontal 0-60 degrees. 90 degrees being veritical, center of mass directly below center of buoyancy, 0 degrees laying horizontal in the water. As for me, I'm close to vertical, 75-80 degrees in the pool (salt water ocean 50-60 degrees). The line to determine angle is from chin to ankle while being completely suspended by the water, or "giving yourself away to the water". Coach Boomer would characterize you as more of a long axis distance swimmer, 400 and above. Long axis meaning free and back. But he notes that doesn't mean you don't do fly or breast - just your body type leans more toward the distance freestyle.

Stuart

[Zenturtle]

I have read that this test should be done with a a sort of relaxed body?
I am describing body position floating level with a pressed chest and keeping the legs up in aquatic posture style, also with arms extended forward.
I guess minimal body tone is needed to mininally keep the body straight?
Otherwise its more a dead mans float with arms and legs hanging down.

[Janos]

My thoughts are that the fundamentals of propulsion are the same for all strokes. Boomer, it seems to me is showing how the dropping of the shoulder and pelvic rotation drives the stroke. The recovery arm movement facilitates this.
The raising and dropping of the shoulder in freestyle is a similar action to the raising and dropping of the body in breaststroke and fly. Arms extend forward, body drops and kick follows. Hips and catch can exploit this action.
Water is essentially a soup of molecules. Turn side on, and you slip between them, the same if you are vertical in the water, you slip between them and submerge. Lying flat on the water, we can take advantage of the density of water. To progress through it , we need to use finesse and adopt fish-like actions to create an aquatic profile. Hence, the dropping of the shoulder in freestyle works; because as the shoulder drops, the opposite hip rises. Doing this we create an undulation across our body, that allows us to minimise the disruption of these molecules and glide through them instead.