DRIVING POSTURE.pdf - Safety.dept.shef.ac.uk

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>- Physiotherapist and ergonomist, Jan Vickery, explains what companies can do
to protect staff whose job involves a lot of driving from musculoskeletal injury.
It is unusual to find a company
that has given the highest priorit.y
to the comfort of all its drivers
when choosing its fleet. It's fair to
say that in most cases, cost must rule.
Function is often considered, but
usually at a superficial level that is
sometimes misinformed as it has not
involved driver input or effective job
evaluation. And the larger the group
of drivers, the less likely it is..that one
make/model of vehicle will fit all or be
suitable for the mal"!Ydifferent job
functions they use the vehicle for.
Fleet managers are tnefefore well advised
to consider erqonomks when selecting thein
fleet, in particular in relation to "fit and >-
"Fleet managers are
well advised to consider
ergonomics when selecting
their fleet. "
The RoSPAOccupational Safety & Health Journal April 2009 zs

~
Health Matters
function". Ideally a range of vehicle makes
and models should be on offer for staff to
choose from.
Employees whose job involves a lot of
driving every day are at risk of developing
musculoskeletal problems such as back or
neck pain and lessoften hip, knee or foot
pain. These workers should be screened to
assesstheir potential risk of developing
musculoskeletal problems. Screening can
identify high risk drivers by asking them
about driving exposure, discomfort, work
activities in the car and lifestyle. Screening
can also help ensure that line managers take
the correct action to protect individual drivers.
Those drivers who are identified as being
at higher risk of developing musculoskeletal
problems or who are already suffering from
discomfort that they associate with driving,
should be the subject of further, more in-depth,
assessment and advice.
One of the most critical risk factors for
musculoskeletal trouble in occupational
drivers is duration of driving. The threshold
of exposure for occupational driving seems
to be around four hours a day. Research
conducted at Loughborough University
showed that sickness absence in drivers due
to back pain was six times greater for drivers
who drove more than four hours a day'.
So for companies, there are obviously huge
business benefits in spending time looking at
vehicle design and dimensions and marrying
these up with driver anthropometrics (body
measurements) and job demands before
choosing a fleet for their workforce, both in
terms of productivity and complying with
their legal duties. But to many firms, vehicle
ergonomics is still an unknown area. Conducting
an assessment is a good place to
start.
Assessment
When a physiotherapist carries out an
assessment of an individual driver, the first
thing we look for are any physical difficulties
the driver has. We use information provided
by the company's occupational health or HR
contact, or from the driver's Gp' if available,
and often the physiotherapist will assessthe
person clinically too, to gain a full understanding
of their physical problem. Armed
with this information, the next step is to
assessthe "fit and function" of the vehicle.
This includes, but is not limited to, the
following:
• Details of driving: miles/annum, typical
journey duration
• Taskanalysis: what is the vehicle used
for, for how long, other jobs
• Vehicle details: make and model, locking,
gearing, sat nav, hands free, boot design
• Work organisation and routine: including
breaking habits
• Static driver posture: neck, back, both
lower limbs and both upper limbs
• Posture during use of pedals, gears,
handbrake, steering wheel, mirrors,
displays, dials, signalling, windows, radio
• Clearance around the body especially
head and legs
• Symmetry of the body, especially around
the steering wheel and pedals
• Dimensions of vehicle and equipment
egoseat dimensions, distance to pedals,
from steering wheel, boot height, boot
sill height etc
• Anthropometrics of driver
• Adjustability of vehicle equipment,
especially seat and steering wheel
• Getting in and out of the vehicle
• Use of vehicle for other tasks, especially
loading
By assessing all these factors, it is possible
to build an objective understanding of where
a mismatch exists between the driver and the
vehicle. Some are a patent mismatch in fit.
For example, a 6ft 4 driver with neck trouble,
who needed to bend his neck sideways to
gain an unobstructed view through the
front windscreen of his rather small vehicle,
or a 5ft 2 delivery driver who couldn't reach
the floor-level handbrake without nearly
coming off her seat.
But the vast majority of problems physiotherapists
see revolve around vehicle seating
"One of the most critical risk factors for musculoskeletal
trouble in occupational drivers is duration of driving. "

It is important to point out that vehicle manufacturers
do spend a lot of money on research
and development of vehicle seating. This
seemsobvious but often surprises those that
come up against difficulties in this regard.
One has to remember that like most things
"ergonomic" there must be compromise.
Vehicle manufacturers include the following
considerations, amongst many others, during
seating design:
• Safety
• The vehicle target population and their
anthropometrics or body dimensions
• Cost
• Function
• Limitations of the intended car dimensions
• Other design aspects of the car
Unlike workstation seating, provision of
bespoke seating is not common in vehicles,
but a seat that has a lot of adjustability is
obviously more likely to fit more people (however,
seating can still be difficult to get right
for some drivers who have a particularly bad
back problem).
Most drivers settle for an angle of about
30 degrees back from the vertical, with the
hips sitting a little lower than the knees.
This is in contrast to computer workstation
seating, where a far less reclined posture is
recommended. There is a good reason for
this - work at a computer requires one to
work forwards, whereas in driving, the steering
wheel, gear stick and displays can be
centred around the "reclined" posture. Of
course, a driver does need to look ahead at
the road so there is a limit to the amount of
backrest recline and it needs to be balanced
with the effect on neck posture.
Some people are critical of the "reclined"
position of vehicle seats. However, the re-
"The vast majority of
problems physiotherapists
see revolve around vehicle
seating. "
clined posture is a perfectly good one provided
that the s-shape of the spine is supported
through good lumbar support. In
fact, research has shown that the discs in the
spine register less pressure when reclined up
to 45 degrees from the vertical", Obviously
for this to work, it's important to get all the
adjustment right. There's no point in huddling
forward over a steering wheel with the
back unsupported by a backrest that is too
reclined.
Function
Poor function usually revolves around
drivers using vehicles for jobs that they were
not designed for. Evaluation of job demands
should ideally be applied to all vehicles where
driving is not the sole function for the vehicle.
For example, in caseswhere the driver will
be moving and handling objects in and out
of the vehicle, a detailed evaluation of the
job is particularly useful to inform the selection
of ideal vehicle design.
Solutions
To address a mismatch between driver and
vehicle, the first step is to try and work within
the boundaries of what is available. Firstly,
adjust what can be adjusted within the
Health Matte rs
vehicle (eg. seat, steering wheel, seatbelts)
to get the driver into a comfortable and
acceptable driving posture. Look at the driver's
habits. How do they use the vehicle? For
example, many sales personnel who spend a
lot of time in their vehicle use a laptop whilst
seated in the driver's seat - this is a habit
that needs to be changed. Although not
ideal, working in the passenger seat is far
preferable than trying to work squeezed
between the steering wheel and the seat.
Also, drivers can develop poor postural habits,
like leaning on an armrest which in turn
causes the spine to side flex (bend).
When conducting an assessment, sometimes
physiotherapists come across a vehicle
"amendment" that is an attempt to solve a
problem but has created a much larger one.
For example, in one case,a lady had removed
her seat's headrest because her pony tail
banged against it causing her to poke her
head forward, resulting in neck pain. She
had lost sight of the fact that safety should
never be compromised in the quest for comfort.
Another example is cushions on drivers'
seats. These are common - but they can
sometimes render the seat unsafe.
If after making all possible adjustments
there is still a mismatch between the driver
and vehicle, it may be necessaryto try a different
vehicle. If one can be found within
the existing fleet, all the better.
It is recommended that drivers trial a
vehicle before committing to it. Many fleet
managers have the negotiating power to
arrange a few days (or weeks ideally) trial of
a vehicle. During a trial, it is useful to provide
the driver with a detailed checklist, to help
them evaluate the suitability of a vehicle. ~
The RoSPAOccupational Safety & Health Journal April 2009 27

Further information
• www.drivingergonomics.comis a website developed by a team led by Or Diane
Gyi, a senior lecturer in ergonomics at Loughborough University. The team has
conducted a lot of research on business driving and ergonomics.
Guidance available on the site covers a range of issues associated with driving,
including car selection, working from the car and seat adjustment, and there is a
useful "Risk management filter" which has been developed as a result of the team's
research findings.
The site also includes a cost benefits checklist, the aim of which is to help OH
professionals demonstrate to senior managers the business benefits of investing in
the occupational health of drivers.
The Highways Agency's Vehicle ergonomics best practice guide can also be downloaded
from the website.
• A guide to selecting cars for company drivers is available to down load for free from
the Chartered Society of Physiotherapy's website: www.csp.org.uk
Takethe pain out of driving includes information on driving position and posture.
• RoSPA'sroad safety department has published free guidance on the use of technology
in vehicles. See:www.rospa.com/roadsafety/resources/employers.htm
Health Matters
"Poor function usually
revolves around drivers using
vehicles for jobs that they
were not designed for. "
This is especially useful when there may be a
choice of vehicles available as checklists can
be compared.
Vehicle assessmentscan be made especially
challenging by the inevitable "politics" that
surround them. Typically, a fleet manager
will be nervous of setting a precedent by
providing a non-fleet vehicle or one that
breaks the "status" ranks for an employee.
However, following an objective assessment
of a driver with back pain, for example, the
fleet manager has the justification for doing
so and the flood gates can be held legitimately
shut.
Drivers can also raise objections to driving
particular vehicles, objections which are
simply not about vehicle ergonomics. I
recently heard of a case of a driver who was
convinced that only a new model high spec
Mercedes would relieve his back pain. However,
through demonstration and education
he was shown that one of the vehicles in the
existing fleet was up to the job. He agreed
to trial it and eventually kept it.
References
1 The prevalence of musculoskeletal
troubles among car drivers. Porter, J.M.
and Gyi, D.E, 2002. Occupational
Medicine, 52, (1),4-12
2 The way you sit will never be the same!
Alterations of lumbosacral curvature and
intervertebral disc morphology in normal
subjects in variable sitting positions using
whole-body positional MRI. 8ashir, W.
et al. 2006. Radiological Society of North
America Conference 2006
(http://rsna2006.rsna.orglrsna2006)
Jan Vickery is a member of ACPOHE
(The Association of Chartered
Physiotherapists in Occupational
Health and Ergonomics). Members
of the association specialise in
the assessment. treatment and
rehabilitation of people with workrelated
musculoskeletal disorders.
www.acpohe.org.uk
The RoSPA Occupational Safety & Health Journal April 2009 29