The ability to move freely without pain is a gift that we often take for granted.
Movement relies on our ability to recruit muscle groups using neuromuscular pathways. Repetitive recuitment will result in strengthening.
Flexibility of our joints greatly helps with ease of movement (yoga or stretching, range of motion).
Maintaining proper posture (core strength and spinal alignment) helps to create a memory for where the bones of the body sit because of the musculature that holds them in place.
As societial contraints (sitting at a computer, in a car, in front the tv) force us into repetitive postures, our ability to move is also restricted.