The Achilles tendon, a fibrous connective tissue, joins the calf muscles to the heel bone. Unlike a muscle, the Achilles tendon does not contract to create force, although it does channel force during actions like walking and jumping. Most styles of yoga, except Yin Yoga, focus on stretching and strengthening muscles, not connective tissue. Stiff muscles can lead to a sore Achilles tendon or Achilles tendonitis, which is aggravated by certain yoga poses.
Tight muscles in the legs, especially in the lower legs, cause Achilles tendonitis. Tight leg muscles arise from standing for long periods, wearing high heels or poorly fitted shoes and from exercising without stretching. During your yoga practice, overextending a stretch or holding a stretch for too short a time can increase muscle tension and lead to Achilles tendonitis.
Handle Achilles tendonitis carefully. A sore Achilles tendon can tear, requiring surgery and a lengthy recovery period. Unless correctly modified, standing yoga poses, forward folds and downward dog may aggravate Achilles tendonitis. Stretching past your comfort level in any yoga pose also increases your chances of injury. If you suspect Achilles tendonitis, consult with your doctor before continuing your yoga practice.
Reduce the speed and intensity of yoga poses to successfully work with a sore Achilles tendon. During yoga class work at your own pace. Execute each pose slowly and carefully. If you fall behind your classmates, take a break in child's pose until you find a good point to rejoin them. Tell your instructor that you have Achilles tendonitis so that she can help you modify poses.
Modifications to basic poses help protect the Achilles tendon. Try warrior I with your feet positioned as in crescent lunge so that only the ball of the back foot is touching the floor. Engage the hamstring muscle of the back leg to support the work of the calf muscles. Begin downward dog with knees bent. Slowly straighten the knees until you just begin to feel the calf stretch, then hold for at least 15 seconds. Forcing the heels to the floor in downward dog will aggravate Achilles tendonitis. Move into forward folds slowly until you just begin to feel a stretch. Hold forward folds at this level while dealing with Achilles tendonitis.
Biff Mithoefer, author of The Yin Yoga Kit, notes that holding yoga poses for extended periods of time while relaxing your muscles corrects the structure of deep connective tissue. Unlike typical yoga classes, Yin Yoga involves gently easing into seated or prone yoga poses without warming up the body. Yin Yoga poses are generally held between five and 20 minutes. Use Yin Yoga as a preventive measure for Achilles tendonitis.