Spring washers, sometimes called disc springs, are a subtype of washers. They lend their mechanical capabilities to the unique profile of the material: when subject to a load, the irregularities of the washer compress with a proportionate resistance to return to their predeflected shape.
You should never stretch a pulled muscle to the point of pain or you risk re-injuring it. Do not overstretch the pulled muscles. Too much stretching can retear injured muscle fibers. Gently stretching a pulled muscle may relax the surrounding muscle fibers, which may be tight in response to the injury.
Tendonitis and other tendon injuries - Treatment. Treating a tendon injury. Tendon injuries sometimes get better within a few weeks, but more persistent cases can last for several months. There hasn't been much research into the best treatments for tendonitis and other tendon injuries, so it's not clear exactly which are the most effective.