You know those stim toys that are like wavy and multi-segmented so they give that clicky-clack sensation as you move it? Imagine that, but every time you had to curl a finger, or bend over, or twist around. Think of your ribs curling inward on impact and how it would then course through the rest of your connected miniature bone links, a wave that goes to your spine where you feel every click-clack disperse the kinetic force. Your skull becomes nothing more than skeletal chainmail for your brain, a simple blow that would be a mild concussion for a solid piece now can cave and crush into the soft gray matter. Your body would probably have to develop chitinous tendons and muscles just to bind shit together so nothing slips out accidentally and unassembled a leg or your spine.

I'd imagine it'd be easier to snap your fingers though so there's that.