Body mechanics means using the body in an efficient and careful way. It involves good posture, balance, and using your strongest and largest muscles for work. Fatigue, muscle strain, and injury can result from the improper use and positioning of the body during activity or rest. Focus on the person’s and your own body mechanics. Good body mechanics reduce the risk of injury.

Principles of body mechanics

Body alignment (posture) is the way the head, trunk, arms, and legs are aligned with one another. Good alignment lets the body move and function with strength and efficiency. Standing, sitting, and lying down require good alignment.

Base of support is the area on which an object rests. A good base of support is needed for balance (Fig. 16-1). When standing, your feet are your base of support. Stand with your feet apart for a wider base of support and more balance.

Fig. 16-1 A, Anterior (front) view of an adult in good body alignment. The feet are apart for a wide base of support. B, Lateral (side) view of an adult with good posture and alignment.

Your strongest and largest muscles are in the shoulders, upper arms, hips, and thighs. Use these muscles to handle and move persons and heavy objects. Otherwise, you place strain and exertion on smaller and weaker muscles. This causes fatigue and injury. Back injuries are a major risk. For good body mechanics:

• Bend your knees and squat to lift a heavy object (Fig. 16-2, p. 212). Do not bend from your waist. Bending from the waist places strain on small back muscles.

• Hold items close to your body and base of support (see Fig. 16-2, p. 212). This involves upper arm and shoulder muscles. Holding objects away from your body places strain on small muscles in your lower arms.

Fig. 16-2 Picking up a box using good body mechanics.

All activities require good body mechanics. You must safely and efficiently handle and move persons and heavy objects. Follow the rules in Box 16-1, p. 212.

Box 16-1

Rules for Body Mechanics

• Keep your body in good alignment with a wide base of support.

• Use an upright working posture. Bend your legs. Do not bend your back.

• Use the stronger and larger muscles in your shoulders, upper arms, thighs, and hips.

• Keep objects close to your body when you lift, move, or carry them (see Fig. 16-2).

• Avoid unnecessary bending and reaching. Raise the bed so it is close to your waist. Adjust the overbed table so it is at your waist level.

• Face your work area. This prevents unnecessary twisting.

• Push, slide, or pull heavy objects whenever you can rather than lifting them. Pushing is easier than pulling.

• Widen your base of support when pushing or pulling. Move your front leg forward when pushing. Move your rear leg back when pulling (Fig. 16-3).

• Use both hands and arms to lift, move, or carry objects.

• Turn your whole body when changing the direction of your movement. Move and turn your feet in the direction of the turn instead of twisting your body.

• Work with smooth and even movements. Avoid sudden or jerky motions.

• Do not lean over a person to give care.

• Get help from a co-worker to move heavy objects. Do not lift or move them by yourself.

• Bend your hips and knees to lift heavy objects from the floor (see Fig. 16-2). Straighten your back as the object reaches thigh level. Your leg and thigh muscles work to raise the item off the floor and to waist level.

• Do not lift objects higher than chest level. Do not lift above your shoulders. Use a step stool or ladder to reach an object higher than chest level.

Ergonomics

Ergonomics is the science of designing the job to fit the worker. (Ergo means work. Nomos means law.) It involves changing the task, work station, equipment, and tools to help reduce stress on the worker’s body. The goal is to eliminate a serious and disabling work-related musculo-skeletal disorder (MSD). MSDs are caused or made worse by the work setting.

Work-related MSDs

MSDs are injuries and disorders of the muscles, tendons, ligaments, joints, and cartilage. They also can involve the nervous system. The arms and back are often affected. So are the hands, fingers, neck, wrists, legs, and shoulders. MSDs are painful and disabling. They can develop slowly over weeks, months, and years. Or they can occur from one event. Pain, numbness, tingling, stiff joints, difficulty moving, and muscle loss can occur. Sometimes there is paralysis.

MSDs are workplace health hazards. Early signs and symptoms include pain, limited joint movement, or soft tissue swelling. Time off work is often needed. According to the U.S. Department of Labor, nursing assistants are at great risk.

Always report a work-related injury as soon as possible. Early attention can help prevent the problem from becoming worse. Also, injuries are often less serious and less costly to treat if they receive early attention. In later stages, the problem can become more serious and harder and more costly to treat.