This technique will reduce tension and improve extensibility throughout the muscles in the back of your legs (hamstrings, calves) through its effects on the nervous system.

Bend your knees and place the foam roller under the knees. Extend your left leg and roll underneath your thigh for 30-60 seconds. To work the calf, bring the foam roller below the knee and roll towards the Achilles tendon for 30-60 seconds. Repeat on the other side.