My grandchild is nearly 18 months old . He doesn't crawl at all . Loves walking holding an adults hand. Can walk a few steps between 2 people. His legs are very straight and he doesn't bend to pick up stuff but sort of reaches down to pick up while his hand is held. He'll stand against sofa by himself but not cruise. He can't get from sitting . Very good fine motor skills.should my son be seeking help?