A variety of positions reduce the ill effects of prolonged standing.
Do workers in your plant stand in one position for hours on end? Any prolonged position can hurt the body. Machine operators and assembly line workers will attest to the physical discomforts they experience. These include: sore feet, swelling of the legs, muscular fatigue, low back pain, and stiffness in the neck and shoulders.
Prolonged and frequent standing causes a variety of health problems. Without some relief by walking, blood may pool in the legs and feet, causing inflammation of the veins. This may progress to painful varicose veins. Excessive standing also causes the joints in the spine, hips, knees and feet to become temporarily immobilized or locked. Such immobility can later lead to rheumatic diseases from degenerative damage to the tendons and ligaments. But there are ways to reduce the ill effects on their posture.
Workstation set up. A stand-up workstation should be adjusted using elbow height as the guide. For example, precision work, such as electronic assembly, requires a work surface that’s five centimetres above elbow height to provide support. Light work, such as assembly line or mechanical jobs, requires a work surface that is five to 10 centimetres below elbow height. Heavy work, demanding downward forces, requires a surface that is 20 to 40 centimetres below elbow height.
Proper position. Those working in a standing position should always face the job, keeping the body close. Adjust the workspace so there’s enough space to change working position. A foot rail or portable footrest shifts body weight from both legs to one or the other. Use a seat whenever possible, or at least during rest breaks. Avoid over-reaching behind or above the shoulder line, or beyond the point of comfort. Instead of reaching, shift feet to face the object. Workers should take frequent rest breaks and find ways to change position as much as possible.
Comfortable footwear. If a worker’s feet aren’t comfortable, neither are the legs, hips and back. Comfort depends largely on footwear. Choose CSA-approved footwear with the proper ratings for the hazards. Shoes should be as wide as the worker’s feet, leaving room to move the toes. Arch supports prevent flattening of the feet, and a heel with a firm grip prevents slipping. Lace-up shoes are best because they tighten the instep and keep the foot from slipping inside the shoe or boot. Heels should be no higher than five centimetres. Padding under the tongue softens the pressure over the bones at the top of the foot. Shock-absorbing insoles are recommended for metal or cement floors.
Proper standing surface. Wooden, cork or rubber-covered floors are preferable to concrete or metal. Mats with slanted edges help prevent tripping on hard floors, but not too cushioned. Too much causes fatigue and increases the hazard of tripping.
Remember, an ideal position is one that changes frequently.
This article was contributed by the Hamilton-based Canadian Centre for Occupational Health and Safety (CCOHS). It provides information, training, education, management systems and solutions that support health and safety programs and the prevention of injury and illness in the workplace. Visit www.ccohs.ca.