My child grips and can't open their hand

Gently massaging the palm, lightly shaking the wrist, or softly stroking the back of the hand can make it easier for the hand to open. Rather than forcing it open, a natural approach is to hold out a different object and say "give me" to encourage them to switch what they're holding. If there's strong tension in the hand, talk with a physical therapist or occupational therapist.