Ox on a Wooden Bridge ©2010 Mark A. Foote
"Ox on a Wooden Bridge", as with "An Empty-Handed Hat", is a Flash illustration of these things: movement in the sacrum, forward and back; support for L4 and L5 from the pelvis, vertically to L4 on inhalation, horizontally to L5 on exhalation (support from the ilio-lumbar ligaments); the movement of the diaphragm in inhalation and exhalation, tied to L1, L2 and L3 and supported by L4 and L5; and the alignment of the legs and pelvis to the sacrum, effected by the weight of the body through the activity of the psoas.
In addition, "Ox on a Wooden Bridge" illustrates: stretches in the ilio-sacral ligaments; activity in the calves generated through these stretches; stretches in the sacro-tuberal ligaments; and activity generated in the sartorious muscles through these stretches.