Farming with physical limitations increases risk in an already dangerous occupation and can lead to secondary injuries. Often these secondary injuries occur because the farmer may attempt work tasks that exceed his/her abilities. Secondary injuries caused by repetitive motion can be prevented by always considering the body's limitations.
The causes of repetitive motion injuries can be classified in the following ways:
- Rapid movement injuries—caused by repeated rapid movements.
- Forceful movement injuries—caused by exertion of muscle movement.
- Static loading injuries—caused by fixed positioning with unsupported limbs.
Repetitive motion injuries are linked to type of work conducted, the tools used, and the design of the work area. Other factors contributing to repetitive strain include excessive work rates, lack of job variation, speed of repetitious tasks, poorly maintained equipment, stress, length of workday, and vibration. Our bodies are simply not designed to work faster, more vigorously, endlessly, or without rest. They break down, just like equipment that is overworked without being properly maintained. The body is forced to work too much with not enough time to recover, and this spiraling effect can cause injuries that might never heal without a long-term break from this exertion or even cause permanent damage such as compression of the nerves and tissue.
General symptoms of repetitive motion injuries:
- Tingling and burning sensations
- Pain, dull ache
- Dry, shiny palm
- Clumsiness of the hands (loss of ability to grasp items, impaired thumb and finger dexterity)
- Swelling around the wrist and hand
- Wasting of the muscles at the base of the thumb
- Aches and pains which may be strongest at night
The range of pain associated with repetitive motion injuries is from "a sense of discomfort" to "excruciating pain." Pain in one area of the body may also radiate to other connecting parts. Pain from the wrist can radiate to the forearm or pain from the shoulder joint can radiate to the back.
What parts of the body are affected?
Bones and muscles make up what is known as the "musculoskeletal system." This provides support and strength, keeps the body moving, and protects internal organs. The bones, connected by joints, serve as levers for the muscles to act upon. The muscles are anchored to the bones by tendons, and ligaments connect two or more bones, cartilages, or other structures. Any activity that wears away at this system may cause a repetitive motion injury. The most affected body parts include:
Guidelines to prevent repetitive motion injuries are:
- Avoid overuse of one part of the body to compensate for a limitation of another part of the body.
- Utilize ergonomic best practices. (See Ohio AgrAbility fact sheet AEX-981.6 at ohioline.osu.edu.)
- Alternate highly repetitive tasks with low repetition tasks to allow for a period of recovery time.
- Reduce the motions that cause symptoms by taking breaks and frequently stretching.
- Utilize ergonomically designed tools and equipment or redesign tools to fit the individual or specific task.
- Tools with poorly fitting components should be eliminated.
- Tools and equipment should be well maintained.
- Apply ice to the pain.
- Ask a doctor about taking pain relievers, cortisone, and anti-inflammatory medicines.
- Try using a splint to relieve pressure on the muscles and nerves.
- Physical therapy can relieve soreness, pain, swelling, and strengthen joints.
This fact sheet was reviewed by Karen Mancl, PhD, Professor, Food, Agricultural and Biological Engineering, The Ohio State University; Josh Svarda, Program Coordinator, Easter Seals Work Resource Center; and John Zeller, Rural Rehabilitation Specialist, Ohio AgrAbility.
Kent McGuire. Ag Stat Secondary Injury Prevention.
National Institute of Neurological Disorders and Stroke. NINDS Repetitive Motion Disorders Information Page. ninds.nih.gov/disorders/repetitive_motion/repetitive_motion.htm.
Repetitive Strain Injury—Fact Sheet. Canadian Union of Public Employees.
About AgrAbility Based Fact Sheets
These fact sheets were developed to promote success in agriculture for Ohio's farmers and farm families coping with a disability or long-term health condition. AgrAbility offers information and referral materials such as this fact sheet, along with on-site assessment, technical assistance, and awareness in preventing secondary injuries. Fact sheets were developed with funding from NIFA, project number OHON0006.