The Achilles tendon inserts on the calcaneus (the heel bone) at a distance of 8 cm from the axis of the ankle joint. If the force generated by the muscles attached to the Achilles tendon is 3000 N and the moment arm of this force about the ankle joint axis is 5 cm, what torque is created by these muscles about the ankle joint?

150 Nm

Explanation:

Given that the Achilles tendon inserts on the calcaneus (the heel bone) at a distance of 8 cm from the axis of the ankle joint. If the force generated by the muscles attached to the Achilles tendon is 3000 N and the moment arm of this force about the ankle joint axis is 5 cm,

To calculate the torque is created by these muscles about the ankle joint, we must ignore Achilles tendon inserts on the calcaneus (the heel bone) at a distance of 8 cm from the axis of the ankle joint.

Using the formula of torque T;

T = Fr

Where r = moment arm of the force about the ankle joint axis which is equal to 5 cm.

F = 3000 N

Torque = 3000 × 5 × 10^-2

Torque = 150 Nm

Therefore, 150Nm torque is created by these muscles about the ankle joint.