Hi,
Iam new here and in Biomechanics So I hope that you can help me a little bit.
Iam trying to calculate CoM position by double integration of acceleration during hopping.
I know that:
Fv – P = m . a
And velocity:
Integral (Fv – P ) = m.V + constant according to [1]
[1] Cavagna G.A., J. Appl. Physiol., 1975. 39(1): p. 174-179.
The value of constant is zero when a subject begins to move on the platform
from the resting condition (V = 0). This means that after the first hop on the force plate the initial velocity (the velocity that we touch on the force place) is no longer zero. I just have one force plane available (60 cm X 40 cm). How can I calculate this velocity (this constant) ?
Another question is this:
To calculate leg spring stiffness I need to calculate the Length spring change that is calculated by
CoM vertical length change + standing CoM position * (1-cos alpha)
How can I determine the standing CoM position?? Most of the papers don’t mentioned how this is done and some use the distance from (greater trochanter to floor). There is another way to determine the standing CoM position ? Or I need to use the distance from greater trochanter to floor?
Kind regards,
Armindo
Iam new here and in Biomechanics So I hope that you can help me a little bit.
Iam trying to calculate CoM position by double integration of acceleration during hopping.
I know that:
Fv – P = m . a
And velocity:
Integral (Fv – P ) = m.V + constant according to [1]
[1] Cavagna G.A., J. Appl. Physiol., 1975. 39(1): p. 174-179.
The value of constant is zero when a subject begins to move on the platform
from the resting condition (V = 0). This means that after the first hop on the force plate the initial velocity (the velocity that we touch on the force place) is no longer zero. I just have one force plane available (60 cm X 40 cm). How can I calculate this velocity (this constant) ?
Another question is this:
To calculate leg spring stiffness I need to calculate the Length spring change that is calculated by
CoM vertical length change + standing CoM position * (1-cos alpha)
How can I determine the standing CoM position?? Most of the papers don’t mentioned how this is done and some use the distance from (greater trochanter to floor). There is another way to determine the standing CoM position ? Or I need to use the distance from greater trochanter to floor?
Kind regards,
Armindo
Comment