The National Strength and Conditioning Association notes that although dips are an effective upper body strengthening exercise, because of your body position and the difficulty of the movement, they pose a high risk for injury, especially shoulder injuries. To reduce your risk of injury, perform a modified dip exercise, which offers more control and resistance options than the standard dip.
Use your legs when performing the dip exercise. Place a bench under the parallel dip bars. Grab the bars, bend your knees and rest your feet on the bench with your weight on your toes and your heels in the air. Your feet support some of your bodyweight, reducing the load you have to press. Bend your elbows to lower your torso toward the floor. When your upper arms are about parallel to the floor, reverse the movement and press back up until your arms are straight. Push through your feet to assist yourself up if needed.
Use a sturdy chair or bench for this dip modification, also called a chair dip. Sit on the bench and grab the edge of the bench, positioning your hands just outside your thighs. If the chair has arms, you can hold onto the arms instead of the edge of the chair; this allows your wrists to stay in a neutral position and may be more comfortable. Place your feet flat on the floor with your knees at a 90-degree bend. With your arms straight, slide your buttocks off the edge of the bench. Keep your back close to the edge at all times; do not allow your body to shift forward and move away from the bench as this places extra tension on your shoulders. Bend your elbows and lower your torso toward the floor until your upper arms are about parallel to the floor. When pressing back up, push through your feet for assistance if needed.
Straight-Leg Bench Dip
The straight-leg bench dip is a slightly more challenging version of the regular bench dip. Perform the movement in the same manner as the bench dip, but extend your legs out in front of you with your heels on the floor, instead of placing your feet flat on the floor. This body position slightly increases the amount of weight you press.
Elevated Bench Dip
The elevated bench dip is more challenging than the straight-leg bench dip -- you elevate your feet instead of resting them on the floor. Set two benches or two chairs a few feet apart. Sit on one bench and place your heels on the other bench. Adjust the position of the benches so your legs are straight, creating a bridge between the two benches. Grab the edge of the bench you are sitting on and slide your buttocks off the bench. Perform the dip movement in this suspended position, which extends your range of motion and increases the amount of weight you press.