Tendinitis is all too-prevalent in dance injuries and sports injuries. In fact, when someone says “I have tendinitis” it usually refers to the Achilles tendon, without being explained, it is that common. Inflammation, or “itis” can occur in any area of the body.The Achilles tendon comes from the lower end of the calf muscles, and inserts, or is attached, to the heel bone. The calf muscles above, and the intrinsic foot muscles below, are supposed to do all the actual work in moving the foot flexed, or extended (pointed, in ballet).If the foot can flex and stretch without changing its angle (curving outward, or sickling out in ballet, or curving inward, sickling in or ‘pigeon toes’), in most cases the tendon will not get irritated.This is presuming that when you are standing on an even surface, the foot is not sloping inward, what people think of as “fallen arches”, or is not sloping outward toward the little toe edge of the foot.Runners and other athletes often work on uneven surfaces and depend on both strength and supportive shoes to minimize the variation in foot angle as it strikes the ground or pushes off. Ballet dancers absolutely depend on foot strength to prevent misuse, as they do not generally wear supports in their ballet shoes and pointe shoes. If needed, however, orthotics, or foot levelers, can be worn in dance shoes.If a dancer or athlete has bowed legs, or hyper-extended legs, there will be an angle created just to have the feet flat on the floor. If this situation is understood, the student can be taught how to avoid inflammation of the Achilles tendon through understanding, and correction of, or accurate compensation for, this particular anatomical detail.Correcting the stance of hyper-extended legs by stacking the skeletal joints (ankles, knees, hips and on up) and holding turnout, will correct the natural pronation (fallen arches) of the feet on the floor. Sometimes this is not even visible to a glance in dancers, due to a strong built-up muscle structure that is deceptive. Even chiropractors and physio therapists have to test dancers’ muscles extensively, in order not to miss this observation, until they gain experience with it.As more and more athletes are studying ballet principles of turnout and footwork to gain an extra advantage in their performance, and prevent sports injuries, hopefully the area of hyper-extension will also be addressed.Bowed legs require an angle of the foot, for it to be flat on the floor. In ballet, correct use of turnout, developing the intrinsic foot muscles, and always having the body weight placed correctly on the feet (hyper-extension and bowed legs tend to throw the weight back) minimizes the overuse and irritation of the Achilles tendon.Both ballet dancers and athletes need the understanding that poorly developed foot muscles lead to exhausting the calf muscles. This in turn creates tension, loss of muscle tone and strength, and the Achilles tendon develops tendinitis.Once inflammation has set in, rest, and icing must be applied. A courageous patience is needed in recovery, as the pressure to stay in the daily competitive drive for a an upcoming exam, performance or team try-out, must be resisted. You long term persistence in your chosen field depends on avoiding a chronic situation.Ballet, dance, and sports injuries can be prevented. If you are a pre-pro, a would-be ballerina, a dedicated recreational dancer or athlete, study all you can about how to avoid overuse and injury of your Achilles tendon.