High Prevalence of Carpal Tunnel Syndrome among Poultry Workers

Musculoskeletal disorders (MSD) of the upper extremities among poultry processing employees are well documented (Lipscomb et al. 2008; Cartwright et al. 2012). The combination of highly repetitive tasks, forceful movements and working in cold temperatures can increase risk for MSDs such as carpal tunnel syndrome, a disabling medical condition affecting the hands and wrists. In 2014, the National Institute for Occupational Safety and Health (NIOSH) was asked to perform a Health Hazard Evaluation at a poultry processing plant in Maryland.

NIOSH evaluated all employees working in receiving, picking, and evisceration at the plant and randomly selected a sample of employees from the debone direct and thigh line departments to participate in the assessment. Researchers found that 81%* of the jobs evaluated, including all jobs in evisceration, involved levels of hand repetition and force over the American Conference of Governmental Industrial Hygienists’ (ACGIH) action limit. These conditions put workers at increased risk for carpal tunnel syndrome and other MSDs. Jobs involving repetition and force at or above the action limit should be redesigned or use automation or other engineering (and/or administrative) controls to prevent MSDs.

NIOSH researchers found that 76% of tested employees had abnormal results from a nerve conduction test while 34% had evidence of carpal tunnel syndrome. To meet the case definition of carpal tunnel syndrome, employees had to meet all of the following criteria: 1) pain, numbness, burning, tingling in the hands or wrists, occurring more than three times or lasting 7 days or longer in the past 12 months, 2) marked or shaded the location of their symptoms in the median nerve distribution area on a hand symptom diagram, and 3) had abnormal median nerve conduction in the affected hand or wrist. The high prevalence of carpal tunnel syndrome at this plant is not surprising given the literature on the topic as well as past NIOSH HHEs in poultry processing showing a link between carpal tunnel syndrome and levels of exposure to hand repetition and force above recommended limits.

Additionally, NIOSH reviewed the Occupational Safety and Health Administration (OSHA) logs for 2010-2013. The plant’s rate of OSHA recordable work-related injuries and illnesses was above the Bureau of Labor Statistics’ poultry processing industry average for 2010 and 2011. Sprain, strain, pain, soreness, inflammation, or repetitive motion entries were the most common OSHA recordable injury at the plant in 2010, 2011, and 2013.

NIOSH recommended that the poultry processing company act to reduce the risk of carpal tunnel syndrome and other MSDs. Key recommendations for employers and employees follow.

What the Employer Can Do

• Implement the 2013 OSHA Guidelines for Poultry Processing and recommendations from poultry industry groups.
• Design job tasks so that levels of hand activity and force are below the action limit of the ACGIH.
• Reduce cone line speeds and use additional cone lines so job tasks are below the action limit of the ACGIH.
• Implement a rotation schedule to reduce stress to specific sets of muscles and tendons.
• Ensure that the knife change-out schedule is strictly followed.
• Provide more breaks during the work shift.
• Implement a standard process to evaluate employee symptoms. Provide appropriate treatment, work restrictions, and medical referrals.

What Employees Can Do

• Report symptoms and injuries promptly to supervisors and onsite medical staff.
• Use only sharp knives for cutting. Keep knives sharp by using mousetraps frequently and changing knives on a regular basis.
• Adjust the standing platforms to the correct height for the task.

Our results underscore the need for ergonomic interventions and improvement of work processes and medical evaluation. Early recognition of, reporting of, and intervention in MSDs can limit injury severity, improve the effectiveness of treatment, minimize the likelihood of a disability or permanent damage, and reduce the rate of workers’ compensation claims.

Jessica Ramsey, MS, CPE
Ms. Ramsey is an industrial hygienist and ergonomist in the NIOSH Hazard Evaluations and Technical Assistance Branch.

Kristin Musolin, DO, MS
Dr. Musolin is a medical officer in the NIOSH Hazard Evaluations and Technical Assistance Branch.

References

Cartwright MS, Walker FO, Blocker JN, Schulz MR, Arcury TA, Grzywacz JG, Mora D, Chen H, Marin AJ, Quandt SA [2012]. The prevalence of carpal tunnel syndrome in Latino poultry-processing workers and other Latino manual workers. J Occup Environ Med 54(2):198–201.

Lipscomb H, Kucera K, Epling C, Dement J [2008]. Upper extremity musculoskeletal symptoms and disorders among a cohort of women employed in poultry processing. Am J Ind Med 51(1):24–36.

*Percentage updated to reflect a change made in the document.