17. Tissue Mechanics

Arrowhead Stadium was the site of the umpteenth meeting of the Kansas City Chiefs and their arch rivals, the Oakland Raiders. Kansas City returned the kickoff to their own 28-yard line and, determined to strike early and often, sent their prime wide receiver on a long down and out into Raider territory. Just as the receiver caught the ball, he was hit by two Oakland defenders, and his knee flexed acutely. The receiver felt an immediate burning pain in the front of his knee and was unable to stand up again. Examination in the locker room by the team physician revealed a high-riding patella and a palpable depression where the patellar tendon normally resided. How could such a well-conditioned athlete sustain a tendon rupture?