A sign of a ruptured tendon is not being able to walk on your toes.

Sonny came back into the kitchen, walking fast, as he always did, on his toes.

Many animal species walk on their toes, and are called digitigrade.

They walked on their toes inside the plane, talked in whispers.

Big, strong, he looked fast the way he walked slightly up on his toes.

He had a curious habit of walking on his toes.

She put her foot down and walked along beside me, on her toes.

He walked on his toes and sang to himself.

I backed out; Lee took the lead up the steps, walking on his toes.

They seem "normal" to you, but maybe you've noticed that they're very uncoordinated or walk on their toes sometimes.