Beyond the costs of an injury — BWC Blog

A good read about prevention of injury and the need to address health disparities.

By Mark Leung, BWC Technical Medical Specialist, Recently promoted from the BWC Safety & Hygiene Fellowship program Occupational health and safety has been a public health focus for many years. Emphasizing worker protection and well-being advances the overall goal of reducing negative health outcomes in the future. The need to address health disparities within the […]

via Beyond the costs of an injury — BWC Blog

Driving is Risk Factor for Low Back Pain

Occupational Medicine, Vol. 48, No. 3., pp. 153-160, 1998, “Musculoskeletal Problems and Driving in Police Officers,” written by D. E. Gyi and J. M. Porter, Vehicle Ergonomics Group, Department of Design and Technology, Loughborough University, Leicestershire, United Kingdom:

In the above-mentioned study, the Occupational Health Department of a rural police force in the United Kingdom had concerns with relation to driving and its link to musculoskeletal disorders.

“There are now an increasing number of researchers whose work implicates prolonged exposure to car driving as a risk factor for low back pain.  However, such epidemiological studies examining the relationship between car driving and back pain or other musculoskeletal troubles are difficult to conduct.  Driving as a task involves prolonged sitting, a fixed posture, and vibration, any of which could directly lead to musculoskeletal trouble.  It is likely that symptoms arise from multiple relationships and influences, (Rey, P., 1979).”

“These police drivers are also deemed to be at particular risk because of the following:

  • They are generally tall males and wear bulky clothing such that seat adjustment may be insufficient to obtain a good posture.
  • They drive fleet cars where the seat and suspension are exposed to excessive wear and tear.
  • They often have to drive in rapid response situations such that they are exposed to fast acceleration and deceleration.
  • Driving is often followed by strenuous physical activity such as lifting and running.
  • They spend most of their eight-hour shift driving or sitting in their vehicle.
  • They often have to take back-seat passengers, such that tall males are unable to take advantage of any seat adjustments that do exist.”

“In a survey of 2,000 U.S. police officers, the number and types of health disorders reported b these officers over a 6-month period were similar to those found in the general public over a 12 month period, (Hurrel, J., 1984).”

The results of the above-mentioned study agree with the findings of other studies that indicate driving a car is a risk factor for the development of low back pain.

What is Your Inclination . . . (ergonomically)?

The Scandinavian Journal of Rehab. Medicine 15:197-203, 1983. “Posture of the Trunk when Sitting on Forward-Inclining Seats,” written by Tom Bendix and Fin Biering-Sorensen from The Laboratory for Back Research, University of Copenhagen, Denmark:

Forward Inclination & Lumbar Lordosis

The above-mentioned study states: “Changes in posture during one hour of sitting were measured by a statometric method on 10 subjects. Four seats were used, one horizontal and three with forward inclinations respectively of 5 degrees, 10 degrees, and 15 degrees. With increasing forward inclination of the seat, the spine moved toward lumbar lordosis.”

Note: Lumbar lordosis is the natural curve of the lumbar spine explained as increased curving of the lumbar spine (which can become flattened when leaning forward while seated on a flat surface, called kyphosis).

Body’s Adaption to Seat Inclination

“A supplementary sample showed that 1/3 of the body’s adaptation to the seat inclination took place in the spine and 2/3 in the hip joints. A tendency to a more vertical position of the trunk as a whole was observed on the 5 degree chair but the posture of the cervical (neck) spine was not influenced by the seat inclination. . .a comfort evaluation showed the 5 degree forward inclination and the horizontal seats to be preferred.”

Previous Studies & Backwards Inclination

The above-mentioned study goes on to discuss the findings of previous studies: “Many investigators (Akerblom, B., 1948; Grandjean, E., 1975; Keegan, J., 1953; Ollefs, H., 1951; Schubert, H., 1962) recommend that the seat surface should be inclined about 5 degrees backwards; one has even suggested 15 degrees backwards, (Rizzi, M., 1969). Others suggest that the seat should be almost horizontal, (Kroemer, K. H. E., 1971; Peters, T., 1969); and in some committees (Comite Europeen de Normalisation, 1979; Engdahl, S., 1971; ISO: Draft International Standard ISO/DIS 5970), a range from 0 degrees to 4 to 5 degrees backwards had been suggested.”

Previous Studies & Forward Inclination

“Another body of opinion focuses on the possible advantages of a forward inclination of either the whole seat (Burandt, U., 1969; Drescher, E.W., 1929; Laurig, W., 1969; Mandal, A.C., 1970 and 1981; Schlegel, K.F., 1940; Staffel, F. 1884), the posterior part (Burandt, U. & Grandjean, E., 1964; Schneider, H.J., et al., 1961), or the anterior half, (Jurgens, H.W. 1969).”

Tiltable Inclination

“Mandal suggests a tiltable seat from -5 degrees (backwards) to +15 degrees (forward); and Kroemer (1971) suggests an adjustable seat slope between -6 degrees (backwards) and +6 degrees (forward), to make it possible to changes the position for different tasks.”

Purpose of Study

“The purposes of the above-mentioned study were:
1. “To compare spontaneously chosen posture when sitting for one hour on each of the four seat inclinations — horizontal, 5 degrees, 10 degrees, and 15 degrees forward — and to estimate the adaptability of the trunk and hip joints to different forward inclinations of the seat.
2. “To follow the changes of the spinal curves during one hour of sitting on one seat.
3. “To evaluate comfort in relation to the different seat inclinations.”

Tiltable Office Chair Furnished to Study Subjects

“To accustom the subjects to a forward-inclining seat, their homes were furnished with a tiltable office chair at least two weeks before the experiment. The seat could tilt from 5 degrees backwards to 15 degrees forwards . . . to ensure that the thighs conformed to the seat surface, height adjustment was effectuated by placing the seat at first a little too high, with the legs hanging freely, and later lowering it until the feet rested on the floor with the lower part of the legs vertical. Approximately 2/3 of the thighs were resting on the seat.

Preference for Horizontal & 5 Degree Inclination

“At the end of the period of sitting, all subjects were asked to estimate the degree of comfort on each specific seat inclination, using a scale from 1 (poor) to 5 (excellent.). The same scale was used to rate the tillable chair they had used for two weeks in their home. The comfort evaluation that was done in the above-mentioned study, “shows a preference for the 0 degree and the 5 degree inclinations.”

Study Evaluation of Tiltable Seat

“The corresponding comfort evaluation of the office chair with the tiltable seat, which the subjects had in their homes, was of the median 3.5 (5 execellent to 1 poor) (range 1-5).”

Increasing Inclination = Advantageous for Lordosis

“With increasing seat inclination forward, the spine changed towards lumbar lordosis. Almost all authors claim such a change as an advantage when sitting, (Akerblom, B., 1948; Burandt, U. & Grandjean, E., 1964; Jurgens, H.W., 169; Schlegel, K.F., 1940; Schneider, H.J. & Lippert, H., 1961; and Snorrason, E., 1955; Staffel, F., 1884).”

Forward Bending & Low Back Pain

Spine, Volume 21, Number 1, pp. 71-78, 1996, “Analysis of Lumbar Spine and Hip Motion During Forward Bending in Subjects With and Without a History of Low Back Pain,” written by Marcia A. Esola, M.S., P.T.; Philip W. McClure, M.S., P.T.; G. Kelley Fitzgerald, M.S., P.T.; and Sorin Siegler, Ph.D., U.S.A.:

In this study, a motion analysis system was used to measure the amount and velocity of lumbar spine and hip motion during forward bending.

The authors begin by citing the following previous findings:

EPIDEMIC OF LOW BACK PAIN

“Disorders of the low back have reached epidemic proportions, (DeRosa, C.P., 1992).”

BILLIONS OF $$$ ANNUALLY, LOST WORK TIME & WORKERS’ COMP CLAIMS

“Epidemiologic studies show that billions of dollars are spent annually on the problem of low back pain, which is one of the most commonly-cited problems for lost work time in industry and Workers’ Compensation claims, (Chase, J.A., 1992; Frymoyer, J.W., 1988; and Pope, M.H., et al., 1991).”

FREQUENT FORWARD BENDING & LOW BACK PAIN

“Researchers have shown an association between frequent forward bending and low back pain, (Berquist-Ullman, M., et al., 1977; Magora, A., 1973; Mellin, G., 1986; Punnett, L, et al., 1991; Svensson H.O., et al., 1989; Videman T., et al., 1989).”

SLOUCHING WHILE SEATED / BENDING AT THE WAIST WHILE STANDING

“Prolonged sitting with the lumbar spine in a flexed position (slouching) and flexed standing postures (bending at the waist) are also associated with an increased risk of low back pain, (Anderson, G.B.J., 1991; Berquist-Ullman, M., et al., 1977; Magora, A., 1972; Punnett, L., et al., 1991; Riihimaki, H., et al., 1989).”

OCCUPATIONS INVOLVING REPETITIVE FORWARD BENDING

“Saunders reports that people with herniated inter-vertebral discs often have a history of an activity or occupation involving repetitive forward bending.”

“Nachemson (1981) has shown that inter-vertebral disc pressure increases 20 percent over that measured in standing when forward bending 20 degrees, and increases 100 percent when bending up to 40 degrees.”

INADEQUATE HIP FLEXIBILITY & EXCESSIVE LUMBAR MOTION

“It has been suggested that inadequate hip flexibility coupled with excessive lumbar motion during forward bending results in low back pain, (Biering-Sorenson, F., 1984; Sahramann, S.A., 1993). . .Sahramann (1993) suggests that excessive lumbar mobility leads to tissue overloading, micro-trauma, and ultimately the development of degenerative joint and disc disease. A person may experience low back pain at any stage of this sequence of events.

FORWARD BENDING = RISK FACTOR FOR LOW BACK PAIN

“Forward bending has been clearly recognized as a risk factor for low back pain. Altered movement patterns of the lumbar spine and hips during forward bending may help explain why forward bending is a risk factor for the development of low back pain.”

HAMSTRING STRETCHING HELPFUL 

In the conclusions, the authors state: “The results provide quantitative data to guide clinical assessment of forward bending motion.  Results also suggest that although people with a history of low back pain have amounts of lumbar spine and hip motion during forward bending similar to those of healthy subjects, the pattern of motion is different.  It may be desirable to teach patients with a history of low back pain to use more hip motion during early forward bending, and hamstring stretching may be helpful for encouraging earlier hip motion.”

MAINTENANCE OF LUMBAR LORDOSIS = DECREASED RISK OF LOW BACK PAIN,  ISCHIUM (BUTT BONE) PAIN, & COCCYX (TAIL BONE) PAIN

MAINTENANCE OF LUMBAR LORDOSIS = DECREASED RISK OF LOW BACK PAIN,  ISCHIUM (BUTT BONE) PAIN, & COCCYX (TAIL BONE) PAIN

Spine, Volume 22, Number 21, pp. 2571-2574, 1997, “Lumbar Lordosis, Effects of Sitting and Standing,” written by Michael J. Lord, M.D.; John M. Small, M.D.; Jocylane M. Dinsay, R.N., M.N.; and Robert G. Watkins, M.D., Kerlan-Jobe Orthopedic Clinic, California, U.S.A.:

The objective of the above-mentioned study was to document changes in segmental and total lumbar lordosis (inward curvature of the lumbar spine) between sitting and standing radiographs (x-rays).

“One hundred and nine patients with low back pain underwent radiography in the sitting and standing positions. The patients ranged in age from 21 years to 83 years (mean age, 47 years) and had had no prior lumbar spine fusion or clinical deformity. Seventy men and 39 women took part in the study.”

DECREASED LUMBAR LORDOSIS & LOW BACK PAIN

In their discussion, the authors state the following:

“Keegan (1953) in a study of the relationship between lordosis and sitting, found the most important factor in low back pain with prolonged sitting to be decreased trunk-thigh angle with consequent fattening of the lumbar curve.  Use of a lumbar roll that increases lordosis has been found to decrease low back pain, (Williams, A.M., et al., 1991).”

DECREASED LUMBAR LORDOSIS & BUTT PAIN / TAIL-BONE PAIN

“With decreased lordosis, sitting pressure increases over the ischium (butt bones) and coccyx (tail-bone) with resultant pain, (Drummond, D.S., et al., 1982 and 1985; Smith, R.M., et al., 1992.)

The following conclusions were made:

“Segmental and total lordosis were significantly different in the sitting and standing postures. Lordosis increased almost 50 percent when the patients moved from the sitting to the standing position. The clinical significance of this data may pertain to:

  1. The known correlation of increased intra-discal pressure with sitting, which may be caused by this decrease in lordosis;
  2. To the benefit of a sitting lumbar support that increases lordosis; and
  3. To the consideration of an appropriate degree of lordosis in fusion of the lumbar spine.”

 

 

 

Musculoskeletal Pain = Leading Cause of Early Pensions

Textbook of Pain, 1998, “Prevention of Disability due to Chronic Musculoskeletal Pain,” written by Steven James Linton:

The above-mentioned chapter in the Textbook of Pain, “examines procedures designed for use in health-care settings to prevent disability due to musculoskeletal pain.”

The following statement is made:

“Because musculoskeletal pain is a major source of suffering, health care, and utilization of compensation, there is a definite need for prevention.  However, prevention is not an easy task because disability is related to a developmental process in which multidimensional factors operate over time to produce significant lifestyle changes.  Research on risk factors indicates that although medical and workplace factors are obvious, psychosocial variables are central to the transition from acute to chronic pain.  The early identification of ‘at-risk’ patients is a key to allocating resources and initiating secondary prevention.”

“Unfortunately, we do not yet understand the exact mechanisms that produce musculoskeletal pain.”

ACUTE PAIN

“Acute pain – Pain which is generally defined as pain up to about three weeks is characterized by temporary decreases in activity, reliance on medication, and help-seeking.  It is accompanied by psychological distress; for example, fear, anxiety and worry, in addition to beliefs that pain is controllable through medical and active coping…The patient may have organic findings as well as muscle spasms.

SUBACUTE PAIN

“Subacute pain – Pain which is considered to be between 3 and 12 weeks.  Patients may exhibit altering patterns of increasing and decreasing activity, and withdraw or become reliant on medication.”

PERSISTENT OR CHRONIC PAIN

“Persistent or chronic pain – Pain which is defined as more than 3 months’ duration, activities may have decreased sharply. . .The pain becomes more constant although patients may experience ‘good’ and ‘bad’ periods.”

RECURRENT MUSCULOSKELETAL PAIN

“Musculoskeletal pain is usually recurrent in nature.  While most episodes of back pain remit rather quickly and most people return to work within 6 weeks, (Reid, et al., 1997), the majority of sufferers will experience several episodes of pain during the course of a year, (Frymoyer, 1992; Nachemson, 1992; VonKorff, 1994; Linton & Hallden, 1997).”

50 % OF ACUTE BACK PAIN SUFFERERS HAVE PAIN 6 – 12 MONTHS LATER

“More than 50 percent of patients with acute back pain will experience another episode within a year (Nachemson, 1992), and prospective studies indicate that almost half will still have significant problems 6 – 12 months later, (Philips & Grant, 1991; VonKorff, 1994; Linton & Hallden, 1997).”

MUSCULOSKELETAL PAIN = LEADING CAUSE OF EARLY PENSIONS

“Firstly, a large number of people suffer from musculoskeletal pain, making it a leading health-care problem even though only a minority develop persistent dysfunction.  Musculoskeletal pain is a leading cause of health-care visits, particularly in primary care,  sick absenteeism, and early pensions, (Frymoyer, 1992; Nachemson, 1992; Skovron, 1992).  However, several studies indicate that over 90 percent of those off work with an acute episode of back pain will return within 3 months, (Waddell, 1996;  Reid, et al., 1997).”

“Secondly, as shown above, musculoskeletal pain is recurrent in nature even though most patients return to work rather quickly after an acute episode.  Although acute sufferers usually feel better and return to work within a few weeks, this does not mean that they have recovered fully or permanently.”

“Thirdly, while up to 85 percent of the population will suffer from musculoskeletal pain, only a small number will account for most of the costs, (Nachemson, 1992; Skovron, 1992; Waddell, 1996).  In general, less than 10 percent of the sufferers may consume up to 75 percent of the resources, (VonKorff, 1994; Reid, et al., 1997).  Thus preventing disability and high-cost cases may result in large economic savings, so that these people constitute a special target for prevention programs.”

MUSCULOSKELETAL PAIN IN SWEDEN & THE NETHERLANDS

“Further, most of the money at this time is spent on compensation, while relatively little is spent on treatment, and almost nothing is invested in prevention.  In Sweden, about 85 percent of the total resources for musculoskeletal pain are spent on compensation as compared to 15 percent for all treatments and drugs, a figure which has remained fairly constant over a 15-year period, (Linton, 1998).”

“Similarly, in The Netherlands, a recent study of all costs due to back pain showed that 93 percent involved compensation and only 7 percent involved treatment, (Van Tulder, et al., 1995).”

PREVENTION NEEDS RESOURCES

“Consequently, until prevention is granted more resources, programs need to be relatively cheap; and this suggests incorporating them into existing practice routines.”

ERGONOMIC RISK FACTORS TO PREVENT

“A host of ergonomic factors, for example, lifting, heavy work, twisting, bending, manual handling, and repetitive work have been found to be associated with musculoskeletal pain, (Pope, et al., 1991; Skovron, 1992).”

“A recent review of some 60 studies revealed a relationship between musculoskeletal pain problems and job demands, control, monotonous work, time pressure, and perceived workload, (Bongers, et al., 1993).”

“If the problem does not remit within 2 – 4 weeks, a formal screening procedure is suggested.”

 

 

Driving = Risk factor for Low Back Pain

Occupational Medicine, Vol. 48, No. 3., pp. 153-160, 1998, “Musculoskeletal Problems and Driving in Police Officers,” written by D. E. Gyi and J. M. Porter, Vehicle Ergonomics Group, Department of Design and Technology, Loughborough University, Leicestershire, United Kingdom:

In the above-mentioned study, the Occupational Health Department of a rural police force in the United Kingdom had concerns with relation to driving and its link to musculoskeletal disorders.

“There are now an increasing number of researchers whose work implicates prolonged exposure to car driving as a risk factor for low back pain.  However, such epidemiological studies examining the relationship between car driving and back pain or other musculoskeletal troubles are difficult to conduct.  Driving as a task involves prolonged sitting, a fixed posture, and vibration, any of which could directly lead to musculoskeletal trouble.  It is likely that symptoms arise from multiple relationships and influences, (Rey, P., 1979).”

“These police drivers are also deemed to be at particular risk because of the following:

  • They are generally tall males and wear bulky clothing such that seat adjustment may be insufficient to obtain a good posture.
  • They drive fleet cars where the seat and suspension are exposed to excessive wear and tear.
  • They often have to drive in rapid response situations such that they are exposed to fast acceleration and deceleration.
  • Driving is often followed by strenuous physical activity such as lifting and running.
  • They spend most of their eight-hour shift driving or sitting in their vehicle.
  • They often have to take back-seat passengers, such that tall males are unable to take advantage of any seat adjustments that do exist.”

“In a survey of 2,000 U.S. police officers, the number and types of health disorders reported b these officers over a 6-month period were similar to those found in the general public over a 12 month period, (Hurrel, J., 1984).”

The results of the above-mentioned study agree with the findings of other studies that indicate driving a car is a risk factor for the development of low back pain.