Updated December 16, 2014.
The Achilles tendon runs along the back of your lower leg and connects the two major calf muscles, gastrocnemius and soleus, to the back of the heel bone. This tendon is helps point the toes (plantar flexion) and contracts during sports the require powerful or explosive movements including sprinting, jumping, cycling or stair running.
The Achilles tendon may be prone to injury, such as a Achilles tendonitis, or and Achilles tendon rupture, if not properly warmed up or if it becomes weak from fatigue or overuse.

Tight calf muscles may also be more prone to injury including calf pulls or strains.

There are many different ways to stretch your Achilles tendon, but here is a simple stretch you can do while standing.

• Stand about an arm's-length from a wall or another sturdy object.
• Lean forward and place both hands on the wall about shoulder width apart.
• Extend one foot (the side to be stretched) behind you with your knee bend and heel on the ground.
• Keep the other foot closer to the wall.
• Lean into wall slightly and bend the knee of the heel to be stretched (keeping the heel down) until you feel a stretch in the back of the lower leg (just above the heel).
• Sink down slowly with your hips to deepen the stretch.
• Hold this stretch for about 30 seconds and change sides.
• This stretch is similar to the calf stretch, however by bending your knee you focus the stretch on the Achilles rather than the calf.