Saturday, April 26, 2008

Space and self management

The ergonomics of police car design ...

"Ergonomics can be defined as the applied science of equipment design. In short, the science of why your computer keyboard is at the angle it is or why that chair lump juts into your lower back. Ergonomics can be understood by knowing the reasons why someone decided to put a button in one place and not another.

Three factors — comfort; convenience and safety — form the idea of good ergonomics for each tool and piece of equipment. These factors are also considered in police vehicle design. No matter how much one fiddles with his Blackberry while driving, not many people use their vehicle as a mobile office more than law enforcement officers. For this reason, officers must spend their days in vehicles with a well thought out ergonomic design. Fortunately, patrol vehicle manufacturers study ergonomics with the law enforcement official in mind.

"Since the vehicle is essentially a mobile office, we want officers to be comfortable," says Sgt. Keith Wilson of the Michigan State Police and test driver for the Michigan State Police Vehicle (MSP) Vehicle Tests. "That consists of comfortable seating, room for their equipment, easy access to instrumentation, easy view of instrumentation and enough room to install equipment such as radars, cameras, computers, guns and things of that nature."

The comfort of officers and the twisting involved in using mobile office equipment are both a concern for vehicle manufacturers. "While different departments use laptops for different things … there is an ergonomic problem from having a computer at a 45-degree angle to the driver," says Michael Blackmer, special vehicle engineering supervisor of Ford Motor Co. "This forces the driver to twist his body [to use the equipment] even though his legs stay forward. These are all considerations that come into play when making a vehicle into a mobile office."

Officers must be able to reach equipment such as laptops, monitors and printers comfortably and safely. When ergonomics is not considered in vehicle design or in the installation of this technology, accessing this equipment causes officers to uncomfortably twist their upper body, putting pressure on the ligaments of the lower back.

"The body is not designed to twist like that," says Dr. Cheryl Mittelstedt, a Fort Atkinson, Wisconsin-based chiropractor with 22 years of experience. "However the body is designed to make corrections every time you move." She continues to explain that keeping one body segment stationary while moving the rest creates unnecessary strain. Constant wear and tear can weaken the thin ligaments in the lower back, allowing the discs to shift. This altered biomechanical state can place pressure on or cause irritation to the nerves that create the sciatic nerve.
Ergonomics issues in the mobile office

The officer keeping his watchful eye on traffic driving by values his vehicle's ergonomics more than the placement of controls and where equipment can be mounted.

Lt. Brian Moran, fleet manager of the Los Angeles County Sheriff's Department and head of the Los Angeles Sheriff's Department Police Vehicle (LASD) Vehicle Tests, views ergonomics as it relates to comfort: how the officer can get in and out of the car, how comfortable it is to work in, and whether it lends him the ability to do his job effectively.

"The concern is not always how comfortable it is to sit in, but whether the vehicle provides the ability to accelerate in order to respond in an emergency traffic situation," Moran adds.

Considerations also arise over the equipment officers wear on their duty belts. When a right-handed officer wears his weapon on his right side, the holster can interfere with the seat belt. This can cause the holster to become unsnapped or entangled in the belt when exiting the vehicle.

However, the officer is backed by vehicle manufacturers, which respond to common design faults and complaints from law enforcement officers. For instance, Ford previously designed a seat with the padding carved out from the bottom of the seat back, providing additional room for the officer's weapon and handheld radio. "An important thing we can do for [officers] is to keep them comfortable, because they are sitting in that seat so much," Blackmer stresses.

The vehicle's ergonomic design becomes more complicated with the addition of communications, computer and accessory mounts. Knowing that each agency sets up its patrol vehicles differently, vehicle manufacturers face challenges when it comes to balancing efficient communications and smart ergonomic design. "When an agency or department purchases a laptop mount, this creates a couple of problems and some risk," explains Blackmer. "When it's opened, it could block out the radio, which might be bothersome. It could block the trunk-release button, the climate control, ashtray, cup holders or anything on that center stack." Ultimately, since the mount is an aftermarket purchase, departments installing any additional equipment should weigh access to communications and accessories versus the convenience of the mount.

Major vehicle manufacturers, such as Ford, Chrysler and General Motors Corp., employ police advisory boards to act as a liaison and a resource for other law enforcement agencies. According to Moran, a member of all three manufacturer advisory boards, officer safety has also been discussed as it pertains to airbag deployment and the relationship of different mounts and equipment."    (Continued via    [Ergonomics Resources]

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