If you have trouble getting up in morning, try opening your blinds to let the sunlight in. (psychlopaedia.org)
A generally healthy and typically agile cat suddenly seems to be having trouble getting up on all four legs and maintaining its balance. (www2.vet.cornell.edu)
He has a bit of trouble getting up after his nap, and is stiff - legged for a few hours now and then. (canismajor.com)