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.
How to prevent tendonitis. Prevention of tendonitis is easy, and everyone who's lifting weights should be doing this by default. First, you need to stretch your muscles regularly. This means before you work the muscle you should be stretching it fully. Make sure you hold the stretch tight for at least 20 seconds to fully stretch the muscle.