To do it, stand with your lower back, shoulders, head, elbows, and wrists pressed against a wall and your feet about six inches away from it. Start with your arms close to your sides and, maintaining all eight contact points, sweep your arms upward, ending in a goalpost position. Pause, then reverse the motion to return to start for one rep. Complete 10 reps.
If any of those body parts lose contact with the wall during the set, you likely lack the core strength and shoulder mobility needed to hold proper posture, Melendez says.
The bottom line:
Correcting these imbalances can ease pain and reduce your injury risk.
Build the necessary core strength by practicing bird dogs, single suitcase carries, and Pallof presses three times per week. For mobility, perform at least three of these shoulder exercises every day.
Try the W test again after 4 to 6 weeks. If you fail, repeat the above cycle. If you pass, keep doing the shoulder drills at least twice a week to maintain your newfound mobility. In your day-to-day, you can reset your posture with this fist technique.