Bone is not dead scaffolding but living tissue, endlessly excavated and rebuilt around its Haversian canals. Each joint type gives a completely different axis of movement: the elbow hinge swings in one plane, the shoulder ball-and-socket sweeps far wider, and a skull suture does not move at all. Osteoporosis drops trabecular density below half; osteoarthritis and fracture visibly collapse the range of motion.
Bone is not dead scaffolding but living tissue, endlessly excavated and rebuilt around its Haversian canals. Each joint type gives a completely different axis of movement: the elbow hinge swings in one plane, the shoulder ball-and-socket sweeps far wider, and a skull suture does not move at all. Osteoporosis drops trabecular density below half; osteoarthritis and fracture visibly collapse the range of motion.
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