Tendon elastic strain energy in the human ankle plantar-flexors and its role with increased running speed
The human ankle plantar-flexors, the soleus and gastrocnemius, utilize tendon elastic strain energy to reduce muscle fiber work and optimize contractile conditions during running. However, studies to date have considered only slow to moderate running speeds up to 5 m s-1. Little is known about how the human ankle plantar-flexors utilize tendon elastic strain energy as running speed is advanced towards maximum sprinting. We used data obtained from gait experiments in conjunction with musculoskeletal modeling and optimization techniques to calculate muscle-tendon unit (MTU) work, tendon elastic strain energy and muscle fiber work for the ankle plantar-flexors as participants ran at five discrete steady-state speeds ranging from jogging (~2 m s-1) to sprinting (=8 m s-1). As running speed progressed from jogging to sprinting, the contribution of tendon elastic strain energy to the positive work generated by the MTU increased from 53% to 74% for the soleus and from 62% to 75% for the gastrocnemius. This increase was facilitated by greater muscle activation and the relatively isometric behavior of the soleus and gastrocnemius muscle fibers. Both of these characteristics enhanced tendon stretch and recoil, which contributed to the bulk of the change in MTU length. Our results suggest that as steady-state running speed is advanced towards maximum sprinting, the human ankle plantar-flexors continue to prioritize the storage and recovery of
tendon elastic strain energy over muscle fiber work.
© Copyright 2014 The Journal of Experimental Biology. The Company of Biologists. Kaikki oikeudet pidätetään.
Aiheet: | juoksu nopeus jänne akillesjänne sprintti kuormitus nivel sääri, jalka jalka energia maksimi |
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Aihealueet: | voima ja nopeus urheilu kestävyys urheilu biologiset ja lääketieteelliset tieteet tekniset ja luonnontieteet |
Tagging: | Sprunggelenk |
DOI: | 10.1242/jeb.100826 |
Julkaisussa: | The Journal of Experimental Biology |
Julkaistu: |
2014
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Numero: | 217 |
Sivuja: | 3159-3168 |
Julkaisutyypit: | artikkeli |
Kieli: | englanti (kieli) |
Taso: | kehittynyt |