Examples include bending wrists while typing, twisting the back and torso while lifting heavy objects. Awkward postures commonly contribute to MSD's because they increase the amount of force and work required to complete a task. Whole body vibration can occur when using equipment such as jackhammers. Contact stress commonly effects the fingers, palms, forearms, thighs, shins and feet. Contact stress may create elevated pressure on a small area, which can decrease blood flow, tendon and muscle movement, and nerve function.
Cold temperatures can reduce dexterity and sensitivity of the hands.
Prolonged contact with cold surfaces can impair dexterity and cause numbness. Cold temperatures present a problem when present with other risk factors. Risks to the upper extremities can be reduced by implementing work-rest regimes, redesigning or replacing hand tools, modifying workstations to eliminate improper postures and contact with hard or sharp surfaces and utilizing personal protective equipment to reduce vibrations from hand held power tools. Back pain may appear suddenly, but is often the result of numerous micro-injuries to the back. Improper posture during manual material handling, poorly designed work stations, and repetitive tasks can all lead to low back pain and injuries.