Table 1.

Changes in bone cells metabolism and in bone mass/structure in patients with long-term immobilization.

	Increased	Decreased
Osteocytes	Apoptosis	Metabolism and function
		Repair of microdamage
Osteoblasts	Apoptosis	Activity
		Synthesis of type I collagen
Osteoclasts	Activity	Apoptosis
Bone homeostasis	Remodeling rate
	Bone resorption	Bone formation
		Bone mineral density*
		Cortical thickness*
		Cortical density*
		Trabecular density*

*The anatomic location and function of the bone in the skeleton account for the magnitude of skeletal response to immobilization.