Both afferent feedback and psychobiological factors are important.
Williamson
Jon W
JW
D000344:Afferent Pathways / Q000502:physiology*; D006990:Hypnosis; D008124:Locomotion / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*