MUSCLES ENGAGED Shoulders The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well. Triceps Triceps are an often forgotten muscle group. Triceps are located on the opposite side of the biceps at the back of the upper arm. Well strengthened and defined triceps make the arm look bigger and sleeker (reducing the "flabby arm" look). Equipment Used Barbell A barbell is a piece of exercise equipment used in weight training, weightlifting and powerlifting. Barbells range in length from 4 feet (1.2 m) to 8 feet (2.4 m) and vary in diameter. Exercise Instructions Step 1 Start in a pressing position with your feet approx hip width apart. Hold the barbell in just above your collar bone and grip the bar slightly wider than your shoulders. Step 2 Press the barbell overhead but do not go into full extension. Leave a soft bend in your arms as you lower the bar behind your head. Step 3 Press the bar from behind your head and return it to the original start position.