Question

When the palmaris longus muscle in the forearm is flexed, the wrist moves back and forth. If the muscle generates a force of 43.5 N and it is acting with an effective lever arm of 1.95 cm , what is the torque that the muscle produces on the wrist

Answer 1

To solve this problem, we must take two important steps. First we will convert all the given units, to international system. Later we will define the torque, which is given as the product between the radius of application of the force and the Force acting on the body. Mathematically the latter is,

$\tau = r F$

Here,

r = Radius

F = Force

Now the units,

$r = 1.95cm = 1.95*10^{-2}m$

Replacing,

$\tau = (1.95*10^{-2})(43.5N)$

$\tau = 0.8483N\cdot m$

Therefore the torque that the muscle produces on the wrist is $0.85N\cdot m$