Preventing Repetitive Stress Hand InjuryBy Denise Monteleone
Most people who experience soreness or numbness in the hand or wrist from pipetting automatically assume they have carpal tunnel syndrome (CTS). In fact, CTS is just one of many repetitive strain injuries (RSIs). These injuries, also known as cumulative trauma disorders (CTDs), are characterized by damage to muscles, nerves, tendons, ligaments, joints, cartilage or spinal discs. Usually, symptoms are gradual in onset as they result from many small injuries sustained over a long period of time. It is the cumulative nature of CTDs that make them dangerous.
Know Your Risk Factors: When looking at your work space and pipetting tasks, it is useful to keep certain risk factors in mind. Exposure to a combination of common risk factors can greatly increase your chances of developing one of the CTDs discussed previously.
Force: Force Manual pipettes require relatively high levels of hand force. Tip insertion, plunger manipulations, and tip ejection require forces that have been shown to exceed recommended risk levels. The bottom line is that 4 kg of ejection force is too much. New pipette designs significantly lower the forces required for plunger activation and tip ejection. Electronic pipettes reduce two major risk factors: force and repetition. Choose a pipette that requires less force and your thumb will thank you for it.
Be aware of your posture: Keep your ears positioned over your shoulder, shoulders in line with your hips, and arms close to your body when possible. It is important that the wrist be held in a neutral position, so that it is not bent up or down or side to side. An awkward posture may lead to injuries.
Static Position: Tightly gripping a pipette handle tightly for extended periods of time reduces the blood flow and may put pressure on nerves. Pipettes with a finger-hook make it easy to rest the hand before, during and after a pipette cycle. Your grip can be relaxed, reducing inflammation of the tendons and possible compression of the median nerve.
Last Modified: May 18, 2009