Turkey Tendons

Tendons are the shock absorbers of the body. Their elastic nature allows them to dissipate some of the initial impact force to protect the leg muscles from damage. In order to learn more about this muscle-tendon interaction, researchers at Brown studied turkeys, whose leg structure and manner of walking are very similar to ours. The broke the gait cycle down into two phases: (1) force rise (when the turkey first lands) and (2) force decay (following the initial jolt of landing). During the rise phase, the muscle fascicles remained a constant length, which means that tendons are absorbing the force by stretching like a spring. In fact, the muscle "pre-activates", becoming stiffer to resist forcible stretching. During the decay phase, the tendon recoils to its original length, transmitting the energy it stored during landing to the fascicles. Because of this delay, the fascicles have enough time lengthen by an appropriate amount to safely absorb the energy from landing. So, what does that mean for runners (whose knees can absorb up to 8x our body weight with each step)? Keep your tendons healthy!