DS is having a harder time rolling from his belly to back. He can do it, but he always puts his arm down by his side and then tries to roll over his arm. It looks very uncomfortable and much harder than just rolling from his elbows. I keep trying to correct him but he still does it!
Edited because I didn't proof read....
Re: Rolling over trouble
"At 5 months your baby will probably be able to lift his head, push up on his arms, and arch his back to lift his chest off the ground. He may even rock on his stomach, kick his legs, and swim with his arms. All these exercises help him develop the muscles he needs to roll over in both directions – likely by the time he's about 6 months old."
Don't freak out yet. My DD apparently rolls often at daycare but hardly at home with me unless she does it by accident. She does scoot across the floor on her back with her feet like crazy and rotates herself this way instead. Attempts and any movement or arching is a positive sign.
Remember, don't judge your baby's development by others!