There is no certain way to tell if sleeping position is causing neck issue to not heal. The only way to see is to try sleeping in a good posture for an extended period and see if things improve.

The way I knew right way was the improvement in my sleep and days after sleeping on my back or even spending the night sleeping in my recliner.

When I had to learn the first time, I was messing up my wrists so I had to wear wrist splits to bed. It is very difficult to sleep with splits unless you are on your back with hands at your side or on your chest.

Adjustable beds make sleeping on your back much easier. Or, using a bed wedge to lift your shoulders and putting a pillow under your knees.

It also helps to not go to bed until you are sleepy. You should be sleepy enough to fall asleep within 5 to 10 minutes. Being to active the hour before a target bed time can make it difficult to fall asleep.

It takes a lot of experimenting to find the system that works. The right mattress, pillow, pajamas or sheets can all make a difference. The goal is to find the combination where you do not have any different levels of sensations. No cold feet, pressure points, itchy fabric, etc. Everything should feel soothing so that your mind does not try to focus on any specific sensation.

It's a challenge but well worth it.