title: Human ankle plantar flexor muscle-tendon mechanics and energetics during maximum acceleration sprinting.
abstract: Tendon elastic strain energy is the dominant contributor to muscle-tendon work during steady-state running. Does this behaviour also occur for sprint accelerations? We used experimental data and computational modelling to quantify muscle fascicle work and tendon elastic strain energy for the human ankle plantar flexors (specifically soleus and medial gastrocnemius) for multiple foot contacts of a maximal sprint as well as for running at a steady-state speed. Positive work done by the soleus and medial gastrocnemius muscle fascicles decreased incrementally throughout the maximal sprint and both muscles performed more work for the first foot contact of the maximal sprint (FC1) compared with steady-state running at 5 m s(-1) (SS5). However, the differences in tendon strain energy for both muscles were negligible throughout the maximal sprint and when comparing FC1 to SS5. Consequently, the contribution of muscle fascicle work to stored tendon elastic strain energy was greater for FC1 compared with subsequent foot contacts of the maximal sprint and compared with SS5. We conclude that tendon elastic strain energy in the ankle plantar flexors is just as vital at the start of a maximal sprint as it is at the end, and as it is for running at a constant speed.
authors: Department of Mechanical Engineering, University of Melbourne, Victoria 3010, Australia Neuromuscular Mechanics Laboratory, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada V5A1S6 adrian_lai@sfu.ca.
authors: Adrian
authors: 0000-0002-8931-0878
authors: A
authors: Lai
authors: Department of Mechanical Engineering, University of Melbourne, Victoria 3010, Australia.
authors: Anthony G
authors: AG
authors: Schache
authors: Performance Science and Innovation, Australian Institute of Sport, Belconnen 2617, Australia.
authors: Nicholas A T
authors: NA
authors: Brown
authors: Department of Mechanical Engineering, University of Melbourne, Victoria 3010, Australia.
authors: Marcus G
authors: MG
authors: Pandy
mesh_terms: D000054:Acceleration; D000328:Adult; D000842:Ankle / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D000069262:Plantar Plate / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013710:Tendons / Q000502:physiology*
keywords: elastic strain energy; muscle fascicle; muscle modelling; running; sprinting; tendon