(1)The Forward-Leaning Posture to Maximize the Use of Elastic Energy
Strain energy is released when the deformed elastic elements of the body recover their resting lengths and original shapes. The stretch-shortening cycle of the Achilles’ tendon is succinctly exhibiting the mechanics of this catapult action, which spontaneously occurs to be utilized as initiatory impulses for various locomotor movements. Walking, skipping, running, and jumping are bipedal movements critically driven by elastic energy.
The relaxation of the diaphragm catalyzes expiration, and the body gradually becomes relaxed, from the pelvic floor muscles, and bent forward to the ground in the concentric phase of exhalation. The forward-leaning posture is achieved through this chain reaction at various degrees of torso angle, upon diverse stances. Furthermore, the storage of strain energy increases, as the muscle-tendon units of the posterior chain are stretched.
In the forward-leaning posture, the body is highly responsive to respiratory stimuli. The following are the two determinants that enhance the connectivity of the upper and lower body parts: (a)compressed abdominal muscles that cause deep expiration setting up a new respiratory and postural balance to be maintained by subsequent inspiration (b)the forefoot bearing the significant amount of body weight upon itself, sufficient to play as the primary base of support.
Exercise Physiology: Theory and Application to Fitness and Performance. S.K. Powers and E.T. Howley. 10th edition. McGraw Hill publishers
Anatomy & Physiology, Edited and Revised by Lindsay M. Biga, Sierra Dawson, Amy Harwell, Robin Hopkins, Joel Kaufmann, Mike LeMaster, Philip Matern, Katie Morrison-Graham, Devon Quick, Jon Runyeon Art edited and created by Leeah Whittier
( http://library.open.oregonstate.edu/aandp/ )
Tendon elastic strain energy in the human ankle plantar-flexors and its role with increased running speed, Adrian Lai, Anthony G. Schache, Yi-Chung Lin and Marcus G. Pandy, 2014. Published by The Company of Biologists Ltd | The Journal of Experimental Biology (2014) 217, 3159-3168 doi:10.1242/jeb.100826
MAXIMIZING THE USE OF ELASTIC ENERGY IN A STRETCH SHORTEN CYCLE, MOVEMENT WILSON, G.J.i ELLIO’FJ!, B.C. Department of Human Movement and Recreation Studies University of Western Australia .+ Australia, 1990
Elastic energy storage in tendons: mechanical differences related to function and age, Robert E. Shadwick, Department of Biology, University of Calgary, Calgary, Alberta T2N 1N4 Canada, J.APPL.PHYSIOL. 68(3): 1033-1040, 1990
Biomechanics: A catapult action for rapid limb protraction, Article in Nature · February 2003, DOI: 10.1038/421035a · Source: PubMed, Allen M. Willson, Glen A.Lichtwark, Johanna Watson
Take-off and landing forces in jumping frogs, Sandra Nauwelaerts1,* and Peter Aerts1,2 1Department of Biology, University of Antwerp (UIA), Universiteitsplein 1, B-2610 Wilrijk, Antwerpen, Belgium and 2Department of Movement and Sports Sciences, University of Ghent, Watersportlaan 2, B-9000 Gent, Belgium, The Journal of Experimental Biology 209, 66-77 Published by The Company of Biologists 2006, doi:10.1242/jeb.01969
The Quadrupedal Nature of Human Bipedal Locomotion, E. Paul Zehr1,2,3, Sandra R. Hundza1,4, and Erin V. Vasudevan5,6 1Rehabilitation Neuroscience Laboratory, University of Victoria, Victoria; 2International Collaboration on Repair Discoveries, Vancouver; 3Centre for Biomedical Research, University of Victoria; 4CanAssist, University of Victoria, Victoria, British Columbia, Canada; 5Motion Analysis Lab, Kennedy Krieger Institute; and 6Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD ZEHR, E.P., S.R. HUNDZA, and E.V. VASUDEVAN