The present study examined the behaviour of the Achilles tendon (AT)
- triceps surae (TS) muscle complex during running and long jump
take-off. High AT forces were measured in the push-off phase in running even
with very low EMG activity. In the long jump, high rate of stiffness
development was a characteristic of the braking phase of the jump. The results
suggest that high and well-coordinated activation patterns of the leg extensor
muscles during the preactivation and eccentric phases together with high
stretching velocities of muscle-tendon complex provide basis for appropriate
tendomuscular stiffness. This together with high force at the end of the
eccentric phase enables an effective push-off (concentric) phase.
Achilles tendon - force - EMG - stiffness - running - long jump