249
edits
Changes
Quadrupedal Mechanics - Anatomy & Physiology (view source)
Revision as of 11:42, 4 March 2013
, 11:42, 4 March 2013no edit summary
::
::
'''Elastic resilience'''
[[File:QMSection2.3.png|thumb|Add caption here]]
When an elastic material is strained, work is done on it and energy is stored in it. Elastic energy is a form of potential energy. A rubber ball falling on to a hard surface converts what was previously kinetic energy into elastic energy on impact. This elastic energy is released again as kinetic energy when the ball bounces. The ball does not, however, attain the same height as previously. The elastic framework of an animal’s body behaves similarly, as it bounces up and down during running (Fig. 2.4). Some of the kinetic energy is lost as heat. The less energy lost in this way, the greater the elastic resilience of the material. Resilience is the work recovered from a material in elastic recoil, expressed as a percentage of the work previously done in straining it (Fig. 2.5). Passive musculoskeletal tissues should be as resilient as possible, to conserve energy.
:2.5 Elastic resilience
:The work done in deforming the material is Fd, the product of force and distance. This is the area under the curve made during the application of the force (horizontal hatching). The work done by the elastic restoring force is the area under the curve made during the removal of the deforming force (vertical hatching). In this example, these two areas are not the same. The difference in area is the energy lost as heat. The resilience is the vertically hatched area as a percentage of the horizontally hatched area.
:Indented line