This layer of muscle runs across your upper back, through your shoulders and up your neck, and is used during daily activities like supporting and turning your head. Lugging a heavy purse around all day on one shoulder can cause some major muscle imbalances within your trapezius.
Best Exercise: Wall Angels
Strengthen your trapezius with this no-equipment-required move, recommends Rick Richey, master instructor for the National Academy of Sports Medicine and owner of R2Fitness in New York, NY. Start standing, feet wide, with your back against a wall, arms extended out to the side with your elbows bent 90 degrees, palms facing forward. Then, while keeping your head, spine, butt, elbows, and backs of your hands against the wall, slide your arms straight up overhead.
Richey recommends starting off by completing one set of 10 reps, and then progress to 2 sets of 15 reps.