If you see an athelete with noticeably great posture, they likely have well developed trapezius, or back, muscles. Overdeveloping the chest muscles will cause the shoulders to hunch forward and limit flexibility, contributing to poor posture. The trapezius is a muscle with three regions, running from the base of the skull to middle of the back. The upper portion shrugs your shoulders. The middle and lower area controls movements such as rowing.
Arm Circles and Dips
Slow deliberate arm circles, done while flexing the muscles in your shoulders and arms will give your traps a workout. Perform large, medium and then small forward circles, 12 times each for three sets. Then do the circles backward. Dips are another body weight exercise that can be done to strengthen your trapezius muscle. If no dip bars are available, you can substitute arms of a chair. You can also hold your body weight off the floor with your hands at your sides fingertips facing forward, in a tuck position, or an L-sit.
Shrugs with weight in your hands or on your shoulders will develop your traps quickly. If weights are unavailable, get creative and find a heavy object; a bag of sand, heavy bucket, chair, printer or child. Perform straight armed shrugs or upright rows in three sets of 10 to 12 repetitions. If possible, place the child or bag of sand on your shoulders and elevate your shoulders several times. If you have no options for added weight, perform an intense shrug and hold it tight for 10 seconds. Release and repeat three times.
Even if you cannot do handstand pushups, just dipping a few inches and extending yourself back up again works the upper fibers of the trapezius. You can modify this exercise by putting your knees on a 24 inch box or chair, your hands on the floor, then lowering your head to the floor and raising it up again. Pushups at an angle, with your hands on a medicine ball or a stability ball will also work your traps. You can also do inchworms, where you would bend at the waist to put your hands on the floor and walk your arms forward, then walk your feet to your hands.
Using a neutral grip or narrow grip with your pullups works your back and targets your traps. To further work the traps, vary the angle of your pull up, moving your chest to the right at the top, and returning to the hang. Repeat going to the left. If this is too difficult, get into the top of the pull-up and move side to side at the top, your left shoulder going toward your right hand, then your right shoulder going toward your left hand. You can further modify this standing on a box or chair, placing most of your weight on your arms, or with a band under one of your feet.
Strengthening Without Weights
The rowing machine, and using the arm pedals on an airdyne are great pieces of exercise equipment work your trapezius muscles. When swimming, freestyle, butterfly, breaststoke and backstroke all work the trapezius muscles. To work them harder, pull only while immobilizing your legs, keeping them afloat with a kickboard or pull buoy between them. Raise and lower yourself a few inches off a chair with your hands on the handles. In a stairwell with your back straight, hold on to the railings, lean back and pull yourself forward and back a few inches at a time. In a door frame with straight arms, press the back of your wrists as hard as you can against the frame for 30 seconds, step out of the doorway and relax.