Tight calf muscles are prone to cramping: the dreaded “charlie horse” that wakes you up in the middle of the night or attacks as you move from sitting to standing. The large muscles in the back of the lower leg are the soleus and gastrocnemius, both of which attach into the Achilles tendon and run vertically along the back of the lower leg. The soleus attaches to the lower leg bones, and the ‘gastrocs’ attach just above the knee on either side of the femur. Because only one of these two muscles (collectively referred to as the Triceps Surae) passes the knee, to effectively stretch them both, you must stretch twice: with the knee bent to stretch the soleus, and with it flexed to stretch the gastrocs.
Stand facing a wall, close enough that you can rest the ball of your foot against it while your heel stays on the ground. Your opposite leg should be a step behind you for balance. Place your hands against the wall and lean forward toward the wall, keeping your knee straight, until you feel a gentle stretch in the back of your leg. Hold this position for about 30 seconds or until the stretch sensation lessens. Slowly bend the knee by lowering your body a bit toward the ground, until a stretch is felt. This time, the stretch sensation will be closer to the Achilles. Hold until the sensation lessens, and then repeat on the opposite leg.