Hamstrings are most active during which period?

Hamstrings are most active during which period?

• A. Just before to just after heel contact
• B. Mid-swing only
• C. Terminal stance only
• D. Pre-swing only

Answer: (A)

The hamstrings have their greatest role in late swing and early stance. As the leg swings forward, they eccentrically contract to decelerate knee extension and prevent the knee from collapsing, setting up a controlled, stable foot contact. This peak activity continues just after heel contact, helping stabilize the knee as weight is placed on that leg. So the period around heel contact—just before and just after—captures the time when the hamstrings are most active. In mid-swing, the demand drops because the leg isn’t undergoing rapid deceleration; in the later stance phases, propulsion and other muscles take on more of the load, so hamstring activity isn’t at its peak.

The hamstrings have their greatest role in late swing and early stance. As the leg swings forward, they eccentrically contract to decelerate knee extension and prevent the knee from collapsing, setting up a controlled, stable foot contact. This peak activity continues just after heel contact, helping stabilize the knee as weight is placed on that leg. So the period around heel contact—just before and just after—captures the time when the hamstrings are most active. In mid-swing, the demand drops because the leg isn’t undergoing rapid deceleration; in the later stance phases, propulsion and other muscles take on more of the load, so hamstring activity isn’t at its peak.