Using any raised platform, support your forefoot and press your heel down. Don't bounce. Hold for six seconds, release, repeat, then switch sides. This will also pick up the gastrocnemius - the inteior calf muscles - and the hamstring.
Using any raised platform, support your forefoot and press your heel down. Don't bounce. Hold for six seconds, release, repeat, then switch sides. This will also pick up the gastrocnemius - the inteior calf muscles - and the hamstring.