Biomechanics Answers

If you expose salt (Na+ CL-) to wound, the Vm (membrane potential) in the sensory neurons according to the goldman-Hodgkin equation would respond by?

a) increasing the membrane permeability to Na+ and Cl-
b) dropping to a lower (more negative) value in neurons exposed to salt
c) raising to a higher (more positive) value in neurons exposed to salt
d) staying at same value as Na+ has a valence of +1 and cl- has valence of -1

how do you calculate muscle force required to maintain the forearm and external weight in static equilibrium

how do you calculate the resultant quadriceps force and angle at which it acts relative to the right horizontal from the individual muscle forces.

how do you calculate the linear distance of the lower leg centre of mass if you know the knee angle flexion and distance between the knee joint centre and lower leg centre of mass

If a person is lying on his/her side, what is the external force that needs to be countered to do knee flexion and extension? My instructor says it is gravity. But how can it be gravity when the line of gravity is running perpendicularly through the plane of motion?

For the Leg Extension, what is/are the
Plane of Motion?
Joints Involved?
Joints Actions?
Axis of Motion?