Posture and Ergonomics Defined
In discussions about ergonomic injury, bad posture and ergonomics go hand-in-hand. Proper posture is defined as “the position in which you hold your body upright against gravity while standing, sitting or lying down…where the least strain is placed on supporting muscles and ligaments”. The joints and bones need to be correctly aligned so that the muscles work properly. With proper posture and ergonomics, there should be a decrease in arthritis and the “abnormal wearing of joint surfaces”. The ligaments should not be stressed and the spine should not be “fixed in abnormal positions”. The body uses energy more efficiently, becoming less fatigued. Strain and overuse issues are reduced, as are muscular and back pain, when good posture and ergonomics are used. Additionally, bad posture contributes to a poor appearance.1 Ergonomics simple means “fitting a job to a person”. This includes office ergonomics, computer ergonomics, and desk ergonomics, along with many other ways of preventing work-related musculoskeletal disorders. Ergonomics can be applied to jobs that involved lifting, bending, reaching, and working with heavy loads or in awkward positions, as well.2
There are many ways to improve posture while sitting. People should sit up with a straight back, with the shoulders back, and the buttocks touching the back of the chair. It is important to maintain “all three normal back curves” when sitting. A lumbar roll or towel can help with back curves. Without the roll or towel, a person can sit at the end of the chair and slouch, then draw up and accentuate the back’s curve as far as is possible, holding for seconds. Then the position can be released by about 10 degrees, and that is considered good sitting posture. The weight should be evenly distributed on both hips, with the knees bent at a right angle (even with or above hip level, slightly). A foot stool may be used, but the legs should not be crossed; in fact, the feet need to be flat on the floor. To have better posture and ergonomics, people should avoid staying in the same sitting position for over 30 minutes. The chair height and work station need to be adjusted so that the worker can sit close and rest the arms and elbows, relaxing the shoulders. Bending and twisting at the waist should be avoided. Standing backbends can stretch the back. These sitting positions should be considered when driving. In terms of lifting, people should avoid awkward or excessively heavy objects (over 30 lbs.). To lift, one needs firm footing with a wide stance, a straight back, and to bend at the hips and knees, not at the waist. It is best not to lift heavy items above the waist level. Getting a good night’s rest is also helpful for work, so people should sleep in a position that maintains the curve of the back. A pillow under the knees for back-sleepers or sleeping on the side with the knees bent is helpful; however, stomach-sleeping is discouraged, especially if the mattress is soft. A firm mattress may be beneficial.3
Exercises to Improve Posture
The best posture exercises engage and strengthen the “core—the abdominal and low back muscles that connect to your spine and pelvis”. There are programs that target the core, such as yoga, core fitness programs, and Pilates, that use “slow, controlled movements”. One exercise is called the Single Leg Extension. In this, the person lies on their back with the knees bent and feet flat, with the hands behind the head. Then they press the lower back into the flow and curl the head up. While exhaling and pulling the navel in, the person pulls a knee to the chest and extends the other leg out straight (at a 45-degree angle). The lower back must remain on the floor and the abdominals need to stay pulled in. If there is lower back arching, then the extended leg should be lifted higher. This can be done for 5-10 extensions per leg. There are more advanced options for this exercise, as well. Another exercise is The New Crunch (Curl-Up). When lying on the back, knees bent and feet flat, with the lower back pressed to the floor, the person can choose to have their hands behind the head or reaching towards the knees. Exhaling and pulling the navel in, the head and shoulders should curl off the floor, and the position should be held and then slowly lowered, repeating three times. This can also be made more intense. A third exercise is the Yoga Sit-Up/Pilates Roll-Up. The starting position is on the back, but with the legs straight and feet flexed. The arms reach overhead on the floor as the lower back is pressed into the floor. Again, exhaling and pulling the navel in, the person rolls up slowly reaching the arms up off of the floor, following with the shoulders and head until sitting up. Then the person rolls down slowly, all the while keeping the abdominals pulled in, and this is repeated three times. The Crossover is performed on the back with the hands behind the head, but the chest is lifted up and the knees are pulled into the chest. One knee pulls into the chest and the other leg is straight while the torso is rotated towards the knee that is bent, and then the legs are switched and the rotation goes the opposite way. This can be repeated 5-10 times. The Cobra Pose starts on the stomach with the palms flat on the floor by the ribs. The legs are straight as the tops of the feet press into the floor. As with the others, exhaling and pulling in the abdominals is important, and then the person raises the head and chest off of the floor using the back muscles (without using the arms to press up). The neck is relaxed, the hip bones are on the floor, and then the position is lowered down slowly. This can be repeated 3-5 times. Finally, the Plank Pose is begun on the hands and knees with the palms of the hands under the shoulders. The legs are extended straight, tucking the toes under, and the position then resembles a pushup. The abdominal muscles are pulled in as the person looks at the floor. This should be held until fatigue, and then the person should rest and repeat. Good posture and ergonomics can be achieved with daily effort.4
Learn more about ergonomics.