What we call the aches, pains, and strains of manual labor are known as work-related musculoskeletal disorders by those who worry about our health.
Musculoskeletal disorders are physical conditions affecting muscles, tendons, nerves, and joints that are not due to acute trauma, such as falling from a ladder.
Musculoskeletal disorders are the leading cause of disability among workers. Between 1997 and 2005, they cost the agriculture industry $136 million and 862,500 lost workdays. In the tree fruit industry, they account for almost a quarter of all Washington State Department of Labor and Industry workers’ compensation claims. Between 1998 and 2004, there were 687 claims for neck, back, and upper extremity disorders and 222 for problems with the lower limbs, with an average of 130 claims per year.
Types of injuries
• Neck: While neck disorders are relatively uncommon, they are the second most costly type of musculoskeletal disorder, averaging $15,813 per claim and require the most time away from work to recuperate (279 days on average).
• Back: Back disorders are more common but less costly (averaging $11,626 per case) and require the least time away from work (195 days). However, if the problem involves a pinched nerve, called sciatica, it is very expensive ($69,237 per case) and results in 554 lost workdays on average.
• Upper extremity: Most of these claims involve the hand and wrist, followed by the shoulder and elbow.
—Carpal tunnel syndrome and tendonitis (tenosynovitis) both result from repetitive motion of the hand and wrist. The average cost of carpal tunnel syndrome is $21,208 per claim, with an average of 250 workdays lost. While tendonitis is less expensive, time loss is comparable.
—Shoulder problems, specifically the very debilitating rotator cuff syndrome, are the most expensive in terms of costs and time off work. Average time lost is almost a year (323 days), and the cost averages $29,877 per claim. Excessive force, repeated elevation, or forward flexion of the arm are the activities most likely to cause this syndrome (see
—Epicondylitis is the least common and least costly ($11,382) of the upper extremity work-related problems, but the recovery time is long, averaging 263 days. It is a slow-healing inflammation of the forearm tendon, which attaches to the elbow. Forceful and repetitive gripping and overuse of the forearm during tasks such as pruning can lead to this problem.
Causes of musculoskeletal disorders
Physical stress on the body’s muscles, tendons, nerves, and joints are the root causes of work-related musculoskeletal disorders. It is not merely how much force, but how long the body part is under stress or how often that matters.
While much has been automated in the tree fruit industry, manual labor is still required in order to produce a quality product. This may involve chronic exposure to physical stresses that lead to musculoskeletal disorders, such as:
• Working for prolonged periods in a stooped position
• Carrying heavy loads in awkward positions
• Working with hands, arms, or elbows above shoulder level
• Kneeling or squatting
• Repetitive forceful gripping
• Subjecting the whole body to continuous vibration
Preventing these injuries takes study and imagination. The study aspect comes through the science of ergonomics, which assesses a worker’s physical capabilities in relationship to the tasks, tools, and environment of the specific job. An ergonomic demonstration project conducted in 2000 in the tree fruit industry documented which tasks are risky and should prompt either employee ergonomic awareness training (caution zones) or workplace changes (hazard zones). The project identified instances of awkward hand and arm positions, awkward neck and back postures, highly repetitive motion, and heavy and frequent lifting in a number of common tasks.
Dealing with these ergonomic risks is where the creativity comes in. It often requires redesigning the tools or a rethinking how the work is conducted. This will help reach the ultimate goal of improving workers’ posture, reducing the physical force required for the task, and limiting exposure to repetitive motions. Here are
• Avoid locating hand tasks or tools above shoulder height. Tools should be within 16 inches of the worker.
• Provide seating if possible because standing causes pooling of the blood and swelling in the legs (more than when walking), which increases the risk of fainting in hot weather.
• Provide a floor mat for workers who are required to stand, and be sure their work table is the proper height. For men conducting light work it should be 43 to 43 inches high, and for heavy work, 36 to 39 inches. For women, the height should be 37 to 39 inches for light work and 33 to 35 inches for heavy work.
• The diameter of tool handles should allow the worker to grip all around the handle with the thumb and fingers overlapping by 3/8 inch.
• To limit the stooping, provide workers with long-handled tools.
• Pruning tools should have handles that are long enough so as to not press into the palm. A spring to keep them in an open position reduces the fatigue associated with prying them back open after each cut. They also need to be covered with rubber or plastic.
• Provide handles for all loads that workers need to lift, and limit the weight of boxes to no more than 50 pounds.
—Give workers the following advice about lifting:
—Position loads between hands to shoulder level. Avoid lifts from the floor and higher than the shoulder.
—Keep the load as close to your body as possible throughout the entire lift.
—Get a good grip and balance the load.
—Never twist while lifting. Turn feet so that they point in same direction as your lift while you turn.
—Avoid carrying a heavy load more than ten feet without getting help or mechanical assistance.
—If you cannot fit the load between your bent knees, lift with a bent back and hips, keeping your knees relaxed. Being close to the load is more important than bending your knees.