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Exercise & fitness

Tendon stiffness

DESehnensteifigkeit

Tendon stiffness describes how much force a tendon transmits per unit of stretch (force divided by length change, usually in N/mm). A related property, Young's modulus, adjusts that for the tendon's cross-section and resting length. In a living person, it is measured by combining ultrasound of the tendon during an isometric muscle contraction with a force gauge (dynamometry). A systematic review (Bohm, Mersmann, and Arampatzis, Sports Medicine - Open, 2015) found what builds it best. Heavy loads (around 80 to 90% of your max) held for longer (around 3 seconds per rep), as in heavy-slow or isometric protocols, produce the biggest gains in stiffness, modulus, and cross-section. Aging, disuse, and tendon disease (tendinopathy) reduce stiffness. And a well-trained tendon stores and returns elastic energy more efficiently, which improves running economy and lowers injury risk.

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This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer