How to Control Repetitive Hand and Wrist Tasks

Overview: The hands and wrists are made up of a

variety of fragile bones, nerves, blood vessels, tendons and ligaments that can be easily damaged if they are misused.

Overview:The following are some of the conditions that

can cause hand and wrist illnesses:• Frequent or repetitive movement of the hand or wrist,

usually associated with awkward wrist angulations • Inappropriate tool and equipment design • Vibrating knives and saws • Poor work station design and arrangement • Cold environments

Reduce Repetitions and Automate Reduce the number of repetitions per shift

– For example, improve the layout of the work station Try to semi or fully automate

Neutral Wrist Maintain neutral (handshake) wrist position.

Straight wrist (Good)

Bent wrist (Bad)

Neutral Wrist

Bad Bad GoodGood

Bend the tool, not the wrist Bent Handled Tool Examples

Reduce Flexion or Deviation of Wrist Design tasks and select tools to reduce

extreme flexion or deviation of the wrist

Avoid Forearm Rotation Avoid inward or outward

rotation of the forearm when the wrist is bent to minimize elbow disorders

Reduce Wrist Force Reduce force or pressure on the wrists and

hands.– For example, any task or tools that generate a bent

wrist when used.

Reduce Wrist Force Reduce force or pressure on the wrists and

hands.– Don’t use short handled pliers and tools with finger

grooves that do not fit the worker’s hand

Reduce Weight and Size Where ever possible, reduce the weight and

size of objects that must be handled repeatedly.

Use Tool Counter-balance Use a counter-balance support for larger,

heavier tools.

Avoid Pounding and Pressing Avoid repeated pounding with the base of the

hand Avoid repetitive, forceful pressing with the

finger tips

Use Power Grip Design tasks so that a power rather than a

pinch grip can be used to grasp materials.– A pinch grip is five times more stressful than a

power grip.– The greater the effort to maintain control of a hand

tool, the higher the potential for injury.

Minimize Reach Avoid reaching more than 15 inches in front of

the body. To minimize shoulder disorders, avoid

reaching above shoulder height, below waist level or behind the body

Avoid Arm Extension Avoid repetitive work that requires the elbow

held straight and the arm extended Provide support devices where awkward body

postures such as elevated hands or elbows and extended arms must be maintained.

Reduce Vibration Select power tools and equipment that

controls vibration to the hands, or reduce the time or need to hold vibrating tools.

Gloves Provide protection for the hands from cold.

Furnish a selection of gloves sizes and counsel workers about over-gripping while wearing gloves.

Optimal Grip Span Optimum grip spans for pliers, scissors, or

tongs, measured from the fingers to the base of the thumb, range from 2.3 to 3.5 inches.

Handle Diameters The recommended handle diameters for

circular-handle tools such as screwdrivers are 1.25 to 2 inches when a power grip is required, and 0.3 to 0.6 inches when a precision finger grip is needed.

Thank you for taking the time to learn about safety and health and how to prevent injuries and illnesses.