During late stance and pre-swing, the foot provides which type of force to the ground?

During late stance and pre-swing, the foot provides which type of force to the ground?

• A. A posteriorly directed force
• B. An anteriorly directed force
• C. A medially directed force
• D. No force

Answer: (A)

During late stance and pre-swing, propulsion comes from the plantarflexors driving the forefoot into the ground. This action pushes the ground backward, so the foot exerts a posteriorly directed force on the ground. By Newton’s third law, the ground pushes the foot forward, propelling the body ahead. An anteriorly directed force would oppose propulsion, a medially directed force isn’t the primary action of push-off, and no force would mean no forward momentum.

During late stance and pre-swing, propulsion comes from the plantarflexors driving the forefoot into the ground. This action pushes the ground backward, so the foot exerts a posteriorly directed force on the ground. By Newton’s third law, the ground pushes the foot forward, propelling the body ahead. An anteriorly directed force would oppose propulsion, a medially directed force isn’t the primary action of push-off, and no force would mean no forward momentum.