Muscle-tendon architecture underlies muscle function. Whereas muscles generally contribute most to mechanical work, tendons provide the majority of elastic energy savings. Isometric or eccentric contractions enhance force and further reduce energy cost. However, elastic savings is probably constrained by the need to reduce compliance for accurate control of position.
Biewener, A ARoberts, T JengComparative StudyReview2000/08/05 11:00Exerc Sport Sci Rev. 2000 Jul;28(3):99-107.