Wall angels strengthen your back muscles and lengthen the muscles in the front of your neck, shoulders, and core.

How to do them:

  1. Stand with your feet approximately 6–8 inches (about 15–20 cm) away from the wall. Rest your butt, back, shoulders, and head against the wall.
  2. Attempt to begin with a neutral spine by drawing your belly button toward your spine. Draw your ribs in and down, feeling the middle of your back connect to the wall.
  3. Tuck your chin slightly, attempting to get the back of your head to touch the wall. If it’s difficult to get your head on the wall, try placing a small pillow behind your head.
  4. Next, reach your arms straight up and put them on the wall overhead, aiming to get the back of your hands to touch the wall in a “V” position. If you have difficulty with any part of this alignment, step your feet further away from the wall and see if that corrects the issue.
  5. Then, begin to bend your elbows as you slide your hands down the wall until your hands are just above your shoulders. Meanwhile, keep your head, trunk, and butt against the wall.
  6. Lower only as much as you can while maintaining good posture without pain (it’s OK to feel a stretch). At the lowest point, hold for a count of 5 before returning to the “V” starting position while maintaining alignment.
  7. Repeat 5–10 reps, stopping if your muscles can no longer hold the postural alignment without pain.

From:
https://www.healthline.com/health/fitness/wall-angels#how-to