Education: Ergonomic Solutions for Electrical Contractors.

Materials Handling: Hazard Index

Electricians may be exposed to the hazards listed below. These are common hazards that occur in the construction trades.

Awkward postures Awkward postures means working with various parts of the body in bent, extended or flexed positions rather than in a straight or neutral position. Working in awkward postures increases the exertion and muscle force that workers must apply to complete a task and compresses tendons, nerves and blood vessels. In general, the more extreme the posture the more force is needed to complete the task. Examples of awkward postures include performing overhead work, bending or twisting to lift an object, typing with bent wrists, and squatting.

Bending the elbow Repetitive elbow bending can irritate nerves and tendons in the forearms, and even lead to epicondylitis, or "tennis elbow".

Bent wrist Working with wrists in a bent rather than straight position can result in ergonomic injuries, especially where the task also involves high hand force. Working with bent wrists puts stress on the tendons and tendon sheaths in the hands and wrists. When the wrists are bent the tendons and sheaths rub against hard bones and ligaments. If this happens repeatedly, the tendons and sheaths can become irritated and inflamed, resulting in injuries such as tendonitis. The inflamed tendons and sheaths can also press against the nerves that run through the wrist to the hand, resulting in carpal tunnel syndrome. General controls to reduce awkward wrist postures: Bent handles that allow work to be done with straight wrists.

Contact stress/trauma Contact stress results from continuous contact or rubbing between hard or sharp objects/surfaces and sensitive body tissue, such as soft tissue of the fingers, palms, thighs and feet. This contact creates localized pressure for a small area of the body, which can inhibit blood, nerve function, or movement of tendons and muscles. Some contact stress problems include: Prolonged use of tools that vibrate, which can cause contact trauma in the palms and fingers. Standing for long periods of time, which increases the "static load" placed on the legs and back. Circulation is reduced, blood pools, and localized fatigue increases the longer employees must stand. Muscles and tendons become more susceptible to strain as they become fatigued from prolonged standing. General controls to reduce contact stress: Use electric or power tools. Attach well-designed handles to tools. Wrap or coat tool handles and grips with cushioning material. Use palm pads. Use sit/stand stools to reduce static loading on legs and back. Use shoes with thick or cushioned soles.

Crouching and kneeling Electrical workers will frequently need to bend or crouch to reach the work space. This kind of activity can contribute to poor circulation of blood, and may injure the knees where they come in contact with the floor.

Repetitive motion Some tasks involve repeating the same actions with little variation. When motions are repeated frequently for prolonged periods, such as several hours without any break or over an entire work shift, there may be inadequate time for muscles and tendons to recover. Highly repetitive tasks often involve the use of only a few muscles or body parts while the rest of the body is unaffected. To reduce the strain that repetitive tasks pose to those body parts, use these solutions: Rotate workers into several different jobs during the course of a work shift is a way to distribute work so that each employee spends less time performing the same repetitive tasks. In order for job rotation to reduce muscle/tendon strain and provide adequate recovery time, the different jobs into which workers rotate need to involve the use of different muscles or body parts.   Design jobs so they include a wider variety of tasks (longer motion pattern) is another way to reduce the frequency and duration of repetitive motions.   Build short micro pauses between motions or tasks is another way to give muscles and tendons recovery time.

Lifting heavy loads Many tasks require workers to lift, push, pull and carry heavy loads. Heavy lifting can result in overexertion and injury to the lower back. How much weight a worker can safely lift depends on a number of factors. When the factors are such that the worker can assume an "ideal" body posture during the lift, the worker is able to lift greater loads. However, when the body posture is not ideal (e.g., back is bent or arms are outstretched), then the amount of weight the worker can safely lift is reduced. Factors affecting how much weight a worker can safely lift include: Lifting factors More weight can be safely lifted when: The amount of weight that can safely be lifted is reduced when: How far from the body the load is held (horizontal distance). The load is close to the body and not too large/bulky, which allows the arms and elbows to be close to the torso during the lift. The load is farther away from the body or is large/bulky, forcing the arms and elbows away from the torso during the lift. How high or low is the lift (vertical distance). The lift is at waist height. The lift must be made from below the knees or above the shoulder. How much the worker must twist to lift and move the load. The lift is performed in front of the body. The worker must twist the torso to lift and move the load. How often the lift is repeated. The lift is performed only occasionally. The lift is performed repeatedly (several times a minute). How far the load is carried. The lift does not involve carrying. The load must be carried a distance (more than 3 feet). How the load is gripped. The load has handles. The load does not have handles or is slippery. General controls to reduce lifting hazards: Use lift assists such as hand trucks, carts, and forklifts. Reduce size of product boxes to lighten load. Arrange work space so employees can move closer to loads and perform lifts with arms close to the body. Use pallets that can rotate. Put objects to be lifted at waist level. Arrange workstation so lifting is done in front, without twisting. Put handles or grips on boxes. Use gloves that aid in holding slippery objects.

Reaching A number of tasks require workers to work with their hands above their head or shoulders, their arms extended to arm's length, or their elbows raised out from their body. These kinds of tasks place stress on the shoulders, elbows and back, and can result in an injury. Elevated reaches - Examples of jobs and tasks that require employees to repeatedly reach or work with their hands above their head or their elbows above their shoulders include: Installing ceiling fixtures Pulling wire in a plenum space Extended reaches - Employees also have to perform extended reaches when there is not adequate access to the work area, extending the elbows away from the body. Examples include: Lifting a bulky, large load Providing improper hand tools may force workers to raise their elbows away from the torso in order to prevent wrist deviation. Using in-line tools on horizontal surfaces can force shorter employees to lift their elbows as high as shoulder height in order to keep their wrists straight. General controls to reduce reaching hazards: Ladders and lifts to reduce reaching. Bent handled tools that allow straight wrists and elbows close to the body.

Static postures Muscle exertions help to circulate blood throughout the body, especially the lower extremities. Continuous blood flow is necessary to deliver nutrients and to remove waste products. Maintaining the same standing posture for an extended period of time can reduce circulation allowing blood to pool in the legs. This can lead to pressure creating varicose veins and reduce nutrients resulting in fatigue in muscles.

Temperature Extreme temperatures can cause problems for workers. Cold temperatures make the muscles less flexible, resulting in muscle strain and pulls. Hot temperatures lead to dehydration and muscle fatigue.

Twisted torso Twisting the torso and spine while working can cause spinal misalignment, muscle pain, and disc ruptures.

Vibration Although using powered hand tools may help reduce employee exposure to risk factors such as repetition and force, they can expose employees to vibration. Vibration restricts the blood supply to the hands and fingers, which, depending on the vibration level and duration of exposure, can contribute to an injury. Signs and symptoms of vibration-induced injury, such as Reynaud's phenomenon, start with occasional numbness or loss of color in the fingertips. They progress to more frequent and persistent symptoms affecting a larger area of the fingers and resulting in reduction in feeling and manual dexterity. Factors that increase the amount of employee exposure to vibration include: Bad power tool design - Even new tools can expose employees to excessive vibration if they are not designed with devices that dampen or shield employees from vibration. Poor power tool maintenance. Old power tools. General controls to reduce vibration: Use low vibration tools. Use vibration dampeners or shields to isolate source of vibration from employee. Inspect and maintain power tools regularly. Limit the duration of tasks that involve vibration, and rotate tasks.