“While obvious, living beings and inanimate objects differ.
The behavior of living beings is intentional and can be unpredictable whereas if the initial state of an inanimate object and the forces acting on the object, its behavior can be predicted using the laws of classical mechanics.
A stone never rolls uphill unless an external force pushes it up while an animal can run uphill using forces they create themselves.
The fact that biological objects are intentional does not mean that they violate the laws of physics. Living beings differ from the inanimate in their ability to turn the laws of physics to their advantage.”
– Mark L. Latash
Notes of this section highly based on Joint Structure and Function: A Comprehensive Analysis and Exercise Education.