In October 2018, researchers associated with the California Department of Public Health (CDPH) issued a study showing that between 2007 and 2014, almost 140,000 workers in the state reported carpal tunnel syndrome (CTS) workers’ compensation claims. This adds up to 6.3 claims per 10,000 full-time equivalent workers. While that figure by itself may not appear high, the more striking data were that reported cases for women were 8.2 per 10,000, or 3.3 higher than the rate for men (2.5).

CTS occurs when the median nerve becomes compressed as it passes through the wrist within the carpal tunnel, resulting in pain, tingling, weakness, or numbness in the hand or the wrist. Occupational risk factors for CTS include engaging in work activities that require forceful, repetitive tasks, prolonged use of the hands or wrists in an awkward posture, or vibration.

Occurrence may be higher

The researchers reported that using the workers’ compensation data was a useful basis for calculating the occurrence of CTS among state workers. However, they also looked at other studies, which suggested that CTS is underdiagnosed or underreported by workers or employers or that healthcare providers outside the workers’ compensation system are treating cases of work-related CTS.

Costs for CTS medical care are estimated at $2 billion annually in the United States, primarily from surgery. Costs for nonmedical treatment (e.g., for mental or psychological health treatment, loss of earnings and productivity, and costs for legal services) are estimated to be much higher.

Sectors/jobs with the highest rates

The CDPH study identified 20 industries with the highest rates of CTS. Among these, three industries had rates approximately six times higher than the average—textile, fabric finishing, and coating mills (44.9); apparel accessories and other apparel manufacturing (43.1); and animal slaughtering and processing (39.8).

The largest numbers of CTS claims were in public administration (8,713 cases), insurance carriers (4,836), grocery stores (4,630), wired and wireless communication (3,412), and employment services (2,763). The occupation categories with the highest CTS rates were production (14.0), material moving (13.4), and office and administrative support (13.0).

The researchers note that for the study period, the rate of CTS decreased over time. This may indicate improved workplace ergonomic design and employment demographic shifts. But the researchers add that this period also saw a decrease in all-cause workers’ compensation claims.

“This could be related to delayed diagnosis and reporting of CTS to workers’ compensation insurers or insurers’ misclassification of workers’ compensation CTS claims,” the study states.

Ergonomic intervention

“Industries and occupations identified with high rates of CTS should consider implementing intervention measures, including ergonomic evaluations and development of tools and instruments that require less repetition and force and correct awkward postures,” the researchers say. “States could use their workers’ compensation data to identify cases of CTS and use this information to target prevention activities.”

In 2014, the Health Hazard Evaluation Program of the National Institute for Occupational Safety and Health (NIOSH) investigated occurrence of injuries, including CTS, at a poultry processing plant in South Carolina. The investigators found that 39 percent of participants in a study group had hand or wrist symptoms.

The report provides specific recommendations for the South Carolina plant and also lists administrative recommendations that employers can undertake in other industries where CTS occurs at a high rate. The recommendations include the following:

• Employ a job rotation schedule in which employees rotate between jobs that use different muscle groups that are below the recommended levels of hand activity and force.
• Eliminate incentive programs that encourage employees to perform only one job task when that task is associated with a high level of repetitive motion.
• Provide more than one break during the workday. Hourly 9-minute breaks may improve employee discomfort ratings without negatively affecting production.
• Encourage employees to report symptoms early to the on-site medical clinic so medical personnel can evaluate these symptoms promptly.
• Provide bulletin board and safety meeting reminders and break room handouts to emphasize the importance of early reporting of possible work-related symptoms.
• Encourage employees to follow up with on-site medical staff and their personal doctor if they were found to have an abnormal nerve conduction test result.
• Institute a medical surveillance program for musculoskeletal disorders to monitor employee health and determine the effectiveness of exposure prevention and medical management strategies.
• Develop procedures for employees to provide information and feedback on work equipment and procedure modifications.
• Add specific information about working height recommendations and adjustable stands to the employee safety training.
• Provide training during supervisor meetings regarding proper setup of standing platforms. For light assembly, the hands should be slightly below elbow height. For work requiring heavy force, the work surface should be below elbow height unless close visual inspection is required.