Musculoskeletal disorders (MSDs) include a number of physical conditions affecting muscles, tendons, nerves, ligaments, joints, and other soft tissues that can be caused, or exacerbated, by work. It is estimated that MSDs account for approximately one-third of injury and illness costs in U.S. industry. Many musculoskeletal conditions can result specifically in chronic or short-term joint pain. One example of joint pain is arthritis, which is the leading cause of work disability, according to the CDC. Arthritis is a condition in which the cartilage surfaces between bones wears away resulting in bone rubbing on bone. In 2007, the annual cost of arthritis and other rheumatic conditions was reported to be $128 billion (MMWR, 2007). This total included an estimated $47 billion in lost earnings. The prevalence of arthritis in the U.S. is projected to increase to nearly 67 million (25% of the adult population) by the year 2030 with 25 million (9.3% of the adult population) projected to be limited in their physical activity because of the condition (Hootman and Helmick, 2006). Working-age adults (45-64 years) will account for almost one-third of arthritis cases. Workplace programs in the areas of safety, ergonomics, wellness, and disability management can all play a role in preventing joint pain and preserving joint health in working individuals of all ages.
Aging is a natural process that encompasses biological changes that tend to be associated with the development of joint pain or that may limit the ability to work with joint pain. In addition to arthritic joint degeneration, aging is associated with loss of muscle mass and muscle function. Functional loss is influenced by changes at the cellular and molecular physiology level. These changes may reduce joint stability and impair normal joint motion that affect the ability to tolerate specific work postures and repetitive motion. With a loss in muscle strength, the same level of physical effort places a greater demand on an individual relative to her/his capabilities.
The relationship between aging and joint pain in the workplace is complex and influenced by a number of factors. For example, national surveys of workers across a wide variety of occupations indicate that not all older workers (50 years and older) report a greater risk of joint pain. Older workers at greatest risk tend to be in jobs that have high physical demands. And once an MSD has occurred, it may take longer for an older worker to return to work. In spite of these factors, studies indicate that older workers suffer no decrease in overall job performance.
While chronological age can’t be slowed, evidence suggests ways in which the development of joint pain, or its effects, can be reduced through intervention. Lifestyle interventions target individual factors that positively affect musculoskeletal health. For instance, obesity has been shown to be a predictor of osteoarthritis (MMWR, 2010), suggesting a transference of benefits from obesity prevention to the prevention of joint pain. Exercise, more specifically resistance training, has been shown to slow, or even reverse, the effects of aging (Melov et al. 2007) and has been suggested to be possibly the most effective mode of exercise for improving quality of life as we age (Hartman et al., 2007). One of the benefits of a well-designed exercise training program may be improved joint health. Employers, like Lincoln Industries, are endorsing workplace exercise programs, in which employees participate at work sometimes even during work hours, as a preventive approach to preventing joint pain and musculoskeletal discomfort (see examples in Promising Practices for Total Worker HealthTM).
Lifestyle and wellness program interventions are important, but alone do not fully address the scope of joint pain and its prevalence in an aging workforce. Workplaces can play an essential role in preserving joint health. To prevent MSDs and joint pain among employees, employers should emphasize workplace equipment and tools that reduce forces, repetition, vibration, and awkward work postures in physically demanding workplaces. Reducing these physical stresses in occupations is paramount to the prevention of joint pain and compliment individual wellness interventions. These interventions often accommodate the employee with existing joint pain by reducing physical demands and allowing the affected individual to work productively. In many cases, workplace modifications to achieve these affects are not costly capital investments. Prevention of a single episode of joint injury is often sufficient for recovery of the cost of the intervention.
Emerging evidence suggests negative health consequences of sedentary work (van Uffelen et al., 2010). This is an interesting contrast in that it gives rise to the redesign of office workplaces to increase overall activity level of the worker (see blog: VHA’s Success with Increasing Movement at Work). Sit/stand workstations have long been endorsed as a human factors solution to problems with seated work. Standing computer workstations are gaining in popularity but are of unproven benefit as prolonged standing has associated health concerns. Other socio-technical solutions have been proposed to integrate lower levels of dynamic activity into traditionally sedentary work in the form of treadmill workstations, accessible indoor walking trails and the use of these to encourage “walking meetings”.
We are interested in hearing about your experience in the prevention and management of joint pain in the workplace. What programs or activities does your organization have in place to prevent and/or reduce the burden of joint pain? What should NIOSH be doing in this area?
Brian D. Lowe, PhD, CPE; Brent A. Baker, PhD, ATC; Jim Grosch, PhD, MBA
Dr. Lowe is a Research Industrial Engineer and Certified Professional Ergonomist with the Human Factors and Ergonomics Research Team in the NIOSH Division of Applied Research and Technology.
Dr. Baker is an Integrative Exercise Physiologist, Board Certified Athletic Trainer, and is Team Leader for the Musculoskeletal Pathomechanics Research Team in the NIOSH Health Effects Labortary Division.
Dr. Grosch is a Senior Research Psychologist with the Work Organization and Stress Research Team in the Division of Applied Research and Technology.
Hartman MJ, Fields DA, Byrne MM, Hunter GR. 2007 Resistance Training Improves Metabolic Economy During Functional Tasks in Older Adults. JSCR 21(1): 91-95.
Hootman JM, Helmick CG. 2006 Projections of US prevalence of arthritis and associated activity limitations. Arthritis Rheum. Jan;54(1):226-9.
Melov S, Tarnopolsky MA, Beckman K, Felkey K, Hubbard A. 2007 Resistance Exercise Reverses Aging in Human Skeletal Muscle. PLoS ONE 2(5): e465.
Morbidity and Mortality Weekly Report (MMWR) National and State Medical Expenditure and Lost Earnings Attributable to Arthritis and Other Rheumatic Conditions – United States, 2003. January 12, 2007/56(01); 4-7.
Morbidity and Mortality Weekly Report (MMWR) Prevalence of Doctor-Diagnosed Arthritis and Arthritis-Attributable Activity Limitation — United States, 2007—2009. October 8, 2010 / 59(39);1261-1265
van Uffelen, J.G.Z. et al. (2010). Occupational Sitting and Health Risks: A Systematic Review. American journal of preventive medicine, 39 (4), 379-388.