Sitting in one position whether it's on a long journey to meetings up and down the motorway or at the controls of a big earth mover can have its consequences.
Jolting of the body as a machine travels over uneven ground can 'shake the body' and cause locking of joints in the spine. Repeated use of controls can lead to Repetative strain injuries of the wrists, elbows and shoulders. Jumping down off large machines can put a shock through the body resulting in a shift of the joints in the spine, not unusually affecting the sacro-iliac joint(s).