We now spend so much time on smart phones to socialize or to get work done that we don't realize the damage we are doing to our spine.
On average an adult head can weigh ~10lbs. When the neck is bent the relative weight is magnified, therefore creating a significant strain on the neck and spine. This in turn leads to potential neck strain and muscular dysfunction... even nerve damage
Tips to protect your neck and spine
Hold your smartphone up and at eye-level while using it
Lay on your back and bring the phone to eye-level while using it
Stretch daily: especially the anterior deltoids (front of shoulders)
Strengthen posterior deltoids (back of shoulders) - especially if you're accustomed to strengthening the anterior deltoids