If you are experiencing back / neck pain after an acute injury or strain here are some tips that should help.

Rest

1-2 days of rest may help your back pain.  Too much rest may be bad for your back and weaken your muscles that support your spine.  Slowly begin to increase your activity.  Change your position every 20-30 minutes or take a break.

Ice / Heat

There are many opinions on which is better, but typically ice will help more the first 48 hours after an injury.  Try a bag of frozen peas and always wrap in a towel (never in direct contact with skin).  You may leave on for 10-15 minutes at one time.  After 48 hours you may want to try heat, bath, or a shower.  Never lie directly on a heating pad (this may cause severe burns.)

When Lying Down

If lying on your side, bend your knees and place a pillow between your legs for support.  While lying on your back, a pillow under your knees may help support your back.  For neck pain, try rolling a towel and place it behind your neck for comfort.