What type of moment occurs at the ankle during heel strike?

At heel strike, the initial contact of the foot with the ground predominantly creates a plantarflexion moment at the ankle. This occurs because as the heel strikes the ground, the body's center of mass is positioned ahead of the ankle joint, leading to a force that tends to push the foot into a plantarflexed position.

The ankle is designed to absorb the impact and stabilize the body during this phase of walking or running, and the muscles (including the gastrocnemius and soleus) must react to control this moment. Although there are components of muscle activity and joint action assisting in preventing excessive plantarflexion, the primary action at the moment of heel strike is counteracting the tendency toward plantarflexion caused by the forces acting on the ankle.

In this context, the other options do not accurately reflect the biomechanical dynamics at play during heel strike. Dorsiflexion moments would not be predominant at this phase because the foot has not yet transitioned into a position of ankle dorsiflexion. A neutral moment implies no significant force acting, which does not occur during this impactful phase. Similarly, an inversion moment does not capture the primary action occurring at heel strike, as it pertains more to the subtalar joint movement rather than the