Workplace Stretching Programs: The Rest of the
Story
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Jennifer A. Hess, DC, MPH and Steve Hecker, MSPH
University of Oregon, Labor Education and Research Center
Introduction
Advocates of workplace stretching programs claim that improving flexibility
can prevent work-related musculoskeletal injuries. Even though many
companies have implemented stretching programs, their effectiveness
has not been demonstrated. Most reports of the benefits of worksite
stretching programs have been published in popular literature or trade
journals. They are based on in-house evaluations that rely on self-reported
outcomes rather than objective measures. More importantly, most studies
seek only to answer one question: does stretching prevent injury?
This single focus eclipses more specific questions that should be
asked about stretching, such as who does stretching benefit and in
what situations? To gain a better understanding, we examined published
reports pertaining to flexibility and stretching among workers. While
the low back was not the target of our search, all the studies found
focused on this body region. Flexibility is usually defined as the
range of movement possible around a specific joint or series of joints.
Workplace Stretching Programs
Our search found only three studies that specifically evaluated workplace-stretching
programs. A stretching program designed to prevent muscle strains
was implemented among pharmaceutical manufacturing employees.(1)
A significant increase in flexibility measurements for all body regions
tested was found after two months of stretching. Participants' perception
of physical conditioning, self-worth, attractiveness, and strength
also increased. The greatest physiologic improvements in stretching
occurred for back flexibility and shoulder rotation, especially in
those who attended more than 13 sessions.
A flexibility program among municipal fire fighters evaluated the
incidence, cost and severity of joint injuries in stretchers versus
nonstretchers.(2) Fire fighters who participated in the
program were more flexible than nonstretchers after six months of
stretching. In the two-year follow up there were 48 injuries among
stretchers and 52 injuries among nonstretchers, not significantly
different.
However, the total dollars spent because of injury was $85,372 for
stretchers versus $235,131 for nonstretchers. A breakdown of costs
revealed that time-loss costs for stretchers were significantly lower
than for nonstretchers, $45,597 versus $147,581 respectively, while
medical costs were not significantly different statistically between
the groups, $39,775 stretchers versus $87,550 in nonstretchers.
A study with manual handling workers looked at strength training combined
with stretching.(3) One group of workers received progressive
resistance strength training alone, while another group received progressive
strength training and trunk flexibility stretches before and after
strength training. Flexibility improved in those who performed strength
training and stretching, but not in those who performed only strengthening
exercises. Also, stretching combined with strength training resulted
in higher percentage increases in static and dynamic strength than
did strength training alone.
The Controversy
Flexibility and Optimal Range of Motion
It is commonly believed that those who are less flexible are more
likely to have musculoskeletal pain and resultant injury. However,
the few studies that have evaluated levels of flexibility among populations
of working people, such as municipal fire fighters and manufacturing
employees had mixed findings.(4, 5, 6, 7, 8, 9) One study
found limited flexion (forward bending) in people with current or
previous back problems, while another study found decreases in trunk
extension (backward bending) in those with low back pain (LBP). Yet
another study showed that men with hypermobile low backs (too much
flexibility) were more likely to experience back pain. These discrepancies
highlight the issue of a beneficial 'functional' or optimal range
of motion. It seems reasonable that individuals who are either too
flexible or not flexible enough may be at an increased risk for injury.
This raises several questions: Is there a healthy functional range
of motion? How much flexibility is too great or too little? And which
workers really need to enhance their flexibility? Perhaps placing
hypermobile workers in a stretching program puts them at greater risk
of injury, while strengthening exercises would be more appropriate.
Hypomobile individuals, on the other hand, might benefit from greater
flexibility, but these people have not been evaluated as a separate
population.
What are the Benefits of Work Place Stretching Programs?
The three studies that evaluated workplace-stretching programs demonstrated
that stretching improves flexibility. However, two of these studies
did not connect improvements in flexibility with meaningful outcome
measures such as injury incidence or severity. Additional studies
are needed to define the contribution of stretching programs in the
workplace. The enhanced strength demonstrated by manual handling workers
who stretch is a notable finding in the real world of workers who
bend, lift, carry, pull and push, over many hours a day. The current
narrow focus on flexibility might be overlooking this valuable aspect
of stretching that could contribute to injury reductions due to worker
fatigue.
Further, the lowered costs associated with reducing injury severity
and time loss noted in firefighters may be as important an outcome
as reduction of injury incidence.
College Athletes versus Industrial Athletes
Workers are many times referred to as ‘industrial athletes,' and sports
studies are frequently cited in the debate over the effectiveness
of stretching at work. Yet, studies of college athletes have diverse
findings; some demonstrate that stretching before an athletic activity
helps reduce the incidence of strains and sprains while others show
that stretching has no effect on injury rates or that it may actually
increase the risk of musculoskeletal injury in athletes. It is also
questionable to rely upon studies relating flexibility and stretching
among college-aged athletes who train vigorously, to workers whose
age, physical condition, training practices and daily physical demands
may differ substantially. It may be erroneous to assume that 'industrial
athletes' behave in the same way as college athletes, and there is
a need for studies specific to working populations.
Workplace Stretching Program Guidelines
Even researchers who are highly critical of the proposed benefits
of stretching recognize that all methods of stretching are not equal.
Since businesses continue to implement these programs, they should
be done correctly in order to enhance the potential to be effective.
Table 1 summarizes stretching guidelines based on a review of the
literature and current American College of Sports Medicine recommendations.(10)
There are three types of stretches: static, ballistic, or proprioceptive
neuromuscular facilitation (PNF). PNF, where a muscle is contracted
for 15 - 20 seconds, relaxed and then stretched, probably provides
the greatest stretching effect, while static stretching, where the
muscle is stretched and held is simpler to perform and is also very
effective. Ballistic stretching, where the individual bounces the
muscle being stretched, has been shown to cause injury and should
be avoided.
Conclusion
Laboratory research on humans and animals has shown that stretching
can alter the elastic properties of muscles and tendons. The presumption
is that for individuals with short or 'tight' muscles stretching increases
flexibility by elongating tissues to a more physiologically normal
range, promoting optimal function and reducing the risk of musculoskeletal
injury.
Studies focusing on working populations, however, have demonstrated
mixed findings regarding flexibility and its relation to injury. The
few available studies specific to workplace stretching programs suggest
that stretching at work enhances worker health and decreases the severity
and cost of treating musculoskeletal injuries, but fail to definitively
prove the case for or against stretching. More information is needed
to clarify the relationship between levels of flexibility, injury,
and the need for regular workplace stretching. Even though existing
studies have shortcomings, many important questions have been raised:
- Is stretching beneficial for those with hypermobility, normal
ranges of motion, or only for those with hypomobility?
- Could stretching actually increase the risk of injury in some
workers?
- In terms of the low back, should stretching focus on flexion
or extension?
- Is stretching beneficial only for the low back? No references
were found that specifically addressed stretching for the prevention
of neck, shoulder, knee or wrist injuries in working populations.
- The findings about stretching in athletes are contradictory,
what does this mean for working populations? Would stretching
have more or less benefit? ?
- Is there an ideal time of shift for stretching? For example,
should workers stretch at the start of their shift or just prior
to some exerting task?
- What constitutes a quality stretching program? Are five or
ten minutes sufficient to stretch the entire body? How many repetitions
are needed to gain maximum benefit? Are all stretches equally
effective and could some be potentially risky for unfit individuals?
The heated nature of this debate has made it difficult to generate
in-depth discussion about the role of stretching, and it is not enough
to say that stretching at work does or does not work. Stretching is
only one component of injury prevention. It is important to remember
that total fitness requires a combination of endurance, strength and
flexibility, and coordination. These other aspects of musculoskeletal
health and an ergonomically optimized work environment must not be
overlooked in an effort for a quick fix.
For a more detailed discussion of this topic see Applied Occupational
and Environmental Hygiene, Vol. 18(5), pp. 331-338, May 2003.
Table 1. Effective Worksite Stretching Program Guidelines
- Warm up for 5 minutes, minimum, prior to stretching
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Exercises should be tailored to commonly performed job duties
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Stretch regularly: 2-3 days/week, minimum
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Perform stretches correctly:
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Use static or PNF stretches
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hold stretch 10-30 seconds
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3-4 repetitions per muscle group
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stretch bilaterally, emphasize tight muscles
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Intensity should be to a position of mild discomfort only
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Trained instructors should lead or monitor classes
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Compliance should be monitored
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Stretch at appropriate work times throughout the day
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Company must be committed to work time and program overhead
costs
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References
1 Moore, T.M., A Workplace Stretching Program. AAOHN J. 46(12):563-568
(1998).
2 Hilyer, J.C., Brown, K.C., Sirles, A.T., et al., A Flexibility
Intervention to Reduce the Incidence and Severity of Joint Injuries
Among Municipal Firefighters. 1990. J. Occup. Med. 32(7):631-637.
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Handling Operations. 1994. Ergonomics. 37(1):95-106.
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7 Bergquist-Ullman, M. and Larsson, U., Acute Low Back
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8 Biering-Sørensen, F., Physical Measurements as Risk Indicators
for Low-Back Trouble Over a One-year Period. 1984. Spine. 9(2):106-119.
9 Troup, J.D., Foreman, T.K., Baxter, C.E., et al., 1987
Volvo Award in Clinical Sciences. The Perception of Back Pain and
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10 General Principles of Exercise Prescription. In: American College
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Philadelphia, PA. pp. 137-164.
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