Post
by johnlvs2run » April 9th, 2008, 6:07 pm
The foot plates are on schedule. Here are a few observations to bring things up to date. First of all regarding the knees.
KNEES
The knees basically follow the feet. The C2 foot plates are turned out about 3%, which puts the knees farther apart through the drive, which can be seen from the following test. #1- Stand with feet shoulder width apart, pointing straight ahead, and squat 1/2 way down to the floor. Notice the distance apart of the knees. #2- Stand with feet shoulder width apart, this time with the feet pointed outward, and again squat 1/2 way down to the floor. Notice the knees are wider apart than before. #3- Stand with feet shoulder width apart, with the feet pointed slightly inward, and squat 1/2 way down to the floor. Notice with #3 it is very EASY to bring the knees together, whereas in #2 it is difficult. The same is the case with the position of the feet on the erg.
My conclusion is that the feet should not be pointed outward at a 3 percent angle.
FOOT PLATE ANGLES
The angle on the model B of about 42.3 degrees was much less than the 45 to 47 degrees of the C, D and E. However, the angle is significantly reduced by wearing shoes that have heel lifts, which most modern shoes have. Not that this is a good thing, but they do reduce the angle of the feet. Shoes with 1/4 inch soles and 3/4 inch heels reduce the 47% angle by 6%, to a 65.3% slope and a 42.3 degree angle.
ANGLES OF THE FEET - CATCH
More important than the angles of the plates, are the angles of the feet. In cycling, the rotation of the spindle is free, to allow the feet to maintain a natural angle, roughly 90 degrees to the lower leg at all times. This is not possible to do with the base of feet maintaining contact with the foot plates on the erg. Squatting down with feet straight and the wall behind results in a 56.9% grade, the slope of my lower legs in relation to my feet.
This converts to a 33.8 percent angle.
The foot plates would need to be at a 33.8 percent angle, in order for me to have my lower legs perpendicular to the ground at the catch, and my feet firmly on the plates. This is considering that my feet would be at their maximum angles.
ANGLES OF THE FEET - FINISH
I've not yet determined approximate angles at the finish, but imagine they would be roughly 90 percent to the lower legs. I plan to work out what that would be for the plates, and design something simple that would work to rotate between the two angles. Suggestions on how to do this are most welcome.
bikeerg 75 5'8" 155# - 18.5 - 51.9 - 568 - 1:52.7 - 8:03.8 - 20:13.1 - 14620 - 40:58.7 - 28855 - 1:23:48.0
rowerg 56-58 5'8.5" 143# - 1:39.6 - 3:35.6 - 7:24.0 - 18:57.4 - 22:49.9 - 7793 - 38:44.7 - 1:22:48.9 - 2:58:46.2