Some babies stiffen up when they're doing something they'd rather not, such as getting a diaper change or being put into their snow suit. If your baby shakes or his eyes wander and get sleepy when he stiffens up, consult his pediatrician to rule out any neurological problems.

Why does my baby stiffen up when crying?

If a baby appears to be arching its back while crying intensely or straightening her legs and screaming at night, it COULD be a sign of something abnormal. Back arching is a common reflex that babies exhibit when they suffer from very acute or strong pain.

What is a stiff baby?

Stiff-baby syndrome is a familial disorder characterized by marked rigidity, with neonatal onset and gradual reduction during infancy, regurgitations, motor delay and attacks of stiffness.