Question

When the palmaris longus muscle in the forearm is flexed, the wrist moves back and forth. If the muscle generates a force of 39.5 N and it is acting with an effective lever arm of 2.55 cm, what is the torque that the muscle produces on the wrist?

Answer 1

Torque produced by muscle is,

$$ \begin{array}{l} \tau=r_{\text {eff }} F \\ \tau=(2.55 \mathrm{~cm})(39.5 \mathrm{~N}) \\ \tau=\left(2.55 \times 10^{-2} \mathrm{~m}\right)(39.5 \mathrm{~N}) \\ \tau=1.01 \mathrm{~N} \cdot \mathrm{m} \end{array} $$