Ergonomics for the Prevention of Musculoskeletal Disorders: Introduction
The Liberty Mutual Insurance Company's Workplace Safety Index shows the importance of ergonomic issues.
The Index lists overexertion, bodily reaction, and repetitive motion as three of the top ten causes of workplace injury.
The three injury categories represented 43.8 percent of the total costs of serious workplace injuries in 2001.
While the total number of serious workplace injuries declined between 1998 and 2001, the cost grew 13.5 percent, or 4 percent after adjusting for inflation. (3)
Many grocery stores have taken actions such as those recommended in this document to help reduce exposures to ergonomic risk factors in their effort to reduce workplace injuries.
Some grocery store work can be physically demanding. Many grocery store workers handle thousands of items each day to stock shelves, check groceries, decorate bakery items, and prepare meat products. These tasks involve several ergonomic risk factors. The most important of these include force, repetition, awkward posture, and static postures. (4)
In the grocery store industry, the presence of these risk factors increases the potential for injuries and illnesses. In these guidelines, OSHA uses the term musculoskeletal disorders (MSD) to refer to a variety of injuries and illnesses, including:
Muscle strains and back injuries that occur from repeated use or overexertion;
Tendinitis; Carpal tunnel syndrome;
Rotator cuff injuries (a shoulder problem);
Epicondylitis (an elbow problem); and
Trigger finger that occurs from repeated use of a single finger.
Putting merchandise in the front of a display case improves the appearance of merchandise. However, working in the back of a deep display case to face or stock merchandise can be awkward and uncomfortable, especially when heavy items are involved.
One familiar solution to this problem is display cases that are stocked from the back. The product, such as cartons of milk, slides down an inclined shelf so that it's always in front of the customer. It's also easier for the employee stocking the shelf.
Recently a market extended this concept to front-loaded cases. The solution was a "dummy" back for the case that was placed at the back of the shelf to limit the reach. Now the merchandise is at the front of the shelf, readily visible to the customer and within easy reach for the worker.
At least one vendor has improved this concept by providing cases with spring-loaded backs. When a customer removes an item, the back pushes the remaining items to the front, keeping them within easy reach. The design makes it easier to stock cases by eliminating the need to reach to the back of the case. The stocker puts the first products in at the front of the shelf, then pushes it back to make room for more items. (5)
Just because an employee develops an MSD does not mean it is work-related. As required by OSHA's recordkeeping rule (29 CFR 1904), employers should consider an MSD to be work-related if an event or exposure in the work environment either caused or contributed to the MSD, or significantly aggravated a pre-existing MSD. For example, when an employee develops carpal tunnel syndrome, the employer needs to look at the hand and forearm activity required for the job and the amount of time spent doing the activity. If an employee develops carpal tunnel syndrome, and his or her job requires frequent hand activity, or forceful or sustained awkward hand motions, then the problem may be work-related. If the job requires very little hand or arm activity then the disorder may not be work-related.
Activities outside of the workplace that involve physical demands may also cause or contribute to MSDs. In addition, development of MSDs may be related to genetic causes, gender, age, and other factors. Finally, there is evidence that reports of MSDs may be linked to occupationally-related psychosocial factors including job dissatisfaction, monotonous work and limited job control (6). However, these guidelines address only physical factors in the workplace that are related to the development of MSDs.
Grocery stores that have implemented injury prevention efforts focusing on musculoskeletal and ergonomic concerns have reported reduced work-related injuries and associated workers' compensation costs. Fewer injuries can also improve morale, reduce employee turnover, encourage employees to stay longer and discourage senior employees from retiring early. Workplace changes based on ergonomic principles may also lead to increased productivity by eliminating unneeded motions, reducing fatigue and increasing worker efficiency. Healthier workers, better morale, and higher productivity can also contribute to better customer service.
These guidelines present recommendations for changing equipment, workstation design, or work methods with the goal of reducing work-related MSDs. Many ergonomic changes result in increased efficiency by reducing the time needed to perform a task. Many grocery stores that have already instituted programs have reported reduced MSDs, reduced workers' compensation costs, and improved efficiency.
Packing produce and other products in ice keeps them fresh and appealing. It also means handling ice - shoveling it, lifting it and shoveling it again. It's heavy work and takes time.
Recently a market devised a method to reduce the amount of time that it takes to put ice on products and that also cut the amount of handling in half. Originally an employee took a cart to the ice machine, scooped up enough ice to fill a cart, wheeled the cart to the display case, and finally scooped the ice from the cart into the display case.
The new machine allows gravity flow of ice and has space underneath for a cart containing four buckets. The ice falls into the buckets and fills them, eliminating half the shoveling. The buckets are convenient to handle and can be picked up to pour the ice into the display case, eliminating the rest of the need to shovel. The net result - less strenuous work, more time saved, and an attractive display. (5)
(2) Clarke, Cynthia M, "Workplace injuries and illnesses in grocery stores", Compensation and Working Conditions, Bureau of Labor Statistics, December 19, 2003.
(3) Fall 2003 Liberty Mutual Workplace Safety Index: Identifies the direct costs and leading causes of workplace injuries. Liberty Mutual Insurance Company. September 2003.
(4) Food Marketing Institute. 1995. Working Smart in the Retail Environment - Ergonomics Guide. Washington, D.C.
(5) Email from Supervalu Supermarkets, Inc. to OSHA. 2003.
Occupational Safety & Health Administration (OSHA)
200 Constitution Avenue, NW
Washington, DC 20210