Decoupling of muscle-tendon unit and fascicle velocity contributes to the in vivo stretch-shortening cycle effect in the male human triceps surae muscle.

ABSTRACT: During the shortening of stretch-shortening cycles (SSCs), muscle force output is enhanced compared with pure shortening (SHO), referred to as the SSC-effect. In general, muscle-tendon unit (MTU), muscle belly, muscle fascicle, and tendon length changes can be decoupled during contraction, which affects force generation and elastic recoil. We researched whether MTU decoupling contributes to the SSC-effect. Participants performed electrically stimulated submaximal fixed-end, SSC, and SHO plantar-flexions on a dynamometer at two velocities (40, 120°/s) and two ranges of motion (15, 25°). Fascicle and tendon length changes of the gastrocnemius medialis, and ankle joint kinematics were assessed by ultrasound and motion capture, respectively. During SSC shortening, ankle joint torque and work,

SUBMITTER: Holzer D 

PROVIDER: S-EPMC11634487 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature