Tendonitis or tendinitis ('itis' denoting inflammation or swelling) used to be thought of as a painful inflammation of a tendon, however, there is rarely much inflammation associated with the condition, thus 'tendonitis' is an inaccurate term, 'tendinopathy' being currently used. More recent research indicates that tendinopathy is an overuse injury resulting in microtears in the muscle fibres, leading to an increase in tendon repair cells, yet an absence of inflammatory cells. This may lead to reduced tensile strength, thus increasing the chance of tendon rupture. Generally tendonitis is referred to by the body part involved, such as Achilles tendonitis (affecting the Achilles tendon), or patellar tendonitis. Chronic overuse of tendons leads to microscopic tears within the collagen matrix, which gradually weakens the tissue.