July 2003
Volume 16, Number 7
Stover Snook has been a Lecturer at the Harvard School of Public Health, Department of Environmental Health, for almost 30 years. At the same time, he was employed as a researcher for the Liberty Mutual Insurance Company. His research centered on occupational health and safety, and more specifically, musculoskeletal disorders. His PhD is from Tufts University.
When I received my bachelor's degree from Hartwick College in 1954, the Korean War had ended, but the Cold War continued. I was drafted within weeks of graduation and although newly married, I was assigned to the 7th Army in Germany. My new father-in-law, an employee of Bell Telephone Laboratories, sent me a copy of the company bulletin, containing an article that described the new field of human engineering, a.k.a. engineering psychology.
While still in Germany, I wrote to three companies mentioned in the article, and eventually was hired by Dunlap and Associates, a small Connecticut consulting firm with military and space contracts.
With support from the company and the Korean Bill, I received my master's in experimental psychology from Fordham University in 1960. I remained at Dunlap for six years, participating in the human factors design of the Atlas, Polaris, Hawk, and Sparrow missile systems, the control systems for the Strategic Air Command and the Tactical Air Command, the cockpit of the F4H aircraft, and the Weather Observing and Forecasting System. It was an exciting job. I was on the leading edge of technology, but I became disenchanted with the work on weapons systems. I would rather save lives than terminate them.
My search for a position that would use my skills in a commercial, non-military setting led me to the Liberty Mutual Insurance Company. Liberty Mutual was the largest writer of workers' compensation insurance in the United States. The company maintained a small research center in Hopkinton, Massachusetts, dedicated to helping people live safer, more secure lives.
I stayed at the research center for 35 years, conducting ergonomics research in areas that were most important to Liberty Mutual and its customers. I was able to conduct experiments on low back pain, manual handling tasks, repetitive motion tasks, heat stress, fatigue, machine guarding, stairway design, and personal protective equipment. Since ergonomics is an interdisciplinary field of study, my research team included a physiologist, an engineer, and a physician assistant/physical therapist. Unlike many commercial companies, Liberty Mutual permitted publication of all results in scientific journals. Liberty Mutual also supported my PhD degree in experimental psychology, received from Tufts University in 1969.
In 1974, I received a part-time appointment at the Harvard School of Public Health. It was an ideal situation - one foot in industry, one foot in academia. My students were primarily physicians, including many flight surgeons from the military, but I also taught nurses, physical and occupational therapists, and industrial hygienists from all over the world.
Teaching health care providers can be an interesting experience. New data often conflict with established opinions. I had to remind my students that only 15 percent of all medical interventions are based on hard, scientific data. The other 85 percent is not necessarily wrong, but it is unproven. For example, in spite of many opinions, the cause of low back pain is unknown. Most treatments in routine use for low back pain are ineffective and some are worse than no treatment at all. Many health care providers can find that message difficult to accept.
I developed a semester course on ergonomics/human factors, and a short course on industrial ergonomics. The semester course was required for many of the graduate programs in occupational health and safety, and the short course was the outreach program to the industrial community. It was a wonderful opportunity to bounce ideas and hypotheses off students, and incorporate their contributions in the research design.
I found it rewarding to see some of my students attain high-ranking positions in the Department of Health and Human Services - and several of my international students returned home to leadership positions in their own countries. Not all of my students came from Harvard. I was able to participate as visiting faculty in numerous universities from Bologna to Taiwan.
At Liberty Mutual, my research made extensive use of psychophysical measures in the experimental investigation of work-related pain, fatigue, discomfort, and overexertion. These are variables with few objective measures. For example, I used psychophysics to develop maximum acceptable weights and forces for lifting, lowering, pushing, pulling, and carrying tasks. A similar methodology was used to determine maximum acceptable forces for repetitive motions of the hand and wrist (flexion, extension, ulnar deviation, and hand grip). A study of stairways used psychophysics to determine the optimal dimensions of risers and treads. At Harvard, I used psychophysics to probe different locations on the face for sensitivity to pressure, in an effort to determine the optimal design of respirators.
I continuously collaborated with company engineers in the application of research results to industrial settings.
Overcoming established beliefs was also an issue with engineers. One of my missions was to collect good, objective data in the laboratory, and then use them to support new ideas in the workplace. For example, good workplace design is more effective in reducing low back disorders than training the individual how to lift. The acceptance of new ideas is much easier when the supporting data are good.
Our research team also conducted epidemiology and cost studies, and evaluations of prevention and treatment. Our studies were among the first to determine the incidence and average cost of compensable low back pain and upper extremity cumulative trauma disorders. Other studies investigated the increased fluid levels in the intervertebral disc during the early morning, and the increased vulnerability to low back pain at that time. A randomized, controlled trial of reducing lumbar flexion during the early morning resulted in significant decreases in the intensity and duration of low back pain.
In 1997, I retired from the Liberty Mutual Insurance Company as assistant vice president and director of the ergonomics laboratory.
It was a very fulfilling journey to conduct practical research in the laboratory, and then discuss and interpret the results in the classroom. However, the journey is not quite over - I continue to lecture at the Harvard School of Public Health.
