Liquid handling ergonomics and performance considerations
Whether identified as Repetitive Stress Disorder (RSD), Repetitive Stress Injury (RSI) or Cumulative Trauma Disorders (CTD’s), musculoskeletal injuries in the workplace have been a serious issue for the past decade, amounting to tens of billions of dollars in costs associated with diagnosis and treatment. In a recent news release summarizing 2009 statistics, the U.S. Department of Labor (DOL), Bureau of Labor Statistics (BLS) reported over 348,740 cases of ergonomically related injuries, which represented over 28% of all cases of workplace injuries and illnesses reported.1 Furthermore, over 40,000 cases were directly related to hand, wrist, finger and arm RSD’s.2
For laboratory technicians, the repetitive nature of standard laboratory techniques, especially pipetting, makes the risk of RSD quite real. In a study published by Bjorksten et al., manual pipetting for more than 300 hours per year increases the risk of hand and shoulder injuries.3 When put in perspective, full-time laboratory technicians who pipette just three hours per day will far exceed the risk factor described in the study. Many RSD’s among lab technicians can be traced to the choice of pipettor and the forces required for insertion and ejection of pipette tips.4
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Figure 1. (Source: Biotix)
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FlexFit Provides Ergonomic Solution
Through an innovative design approach and a focus on ergonomic solutions, Biotix has developed a new feature called FlexFit. This exclusive feature provides flexibility on the proximal end of pipette tips, reducing the necessary insertion and ejection forces between a pipettor and pipette tip. FlexFit has been incorporated into the Biotix branded universal fit pipette tips, and provides not only a better seal, but also improve ergonomics across a broad range of pipettors. In a comprehensive study performed by U.S. Ergonomics, an independent testing laboratory, Biotix demonstrated superior ergonomic performance among all products tested (Fig. 2). Study data revealed that Biotix tips had the lowest measured forces for application and ejection (Fig. 3, 4), had the lowest perceived effort by study participants, and was ranked highest by professional lab technicians as the most preferred pipette tip tested (Fig. 5).
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Figures 2 and 3. (Click each chart to enlarge)
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Ergonomic Study Design
Controlled laboratory testing was conducted by certified professional ergonomists at U.S. Ergonomics. Based on the stringency of its testing standards, U.S. Ergonomics is one of the few independent testing laboratories in the United States to provide ergonomic product certification. In this study, eleven lab technicians (three women, eight men) who each had been using pipettors for over four years, for an average of up to 3.3 hours per day, were recruited as test subjects. While wired to an EMG (Fig. 1), the test subjects ran through a number of pipetting tasks, including:
• Full Cycle Test – Test subjects completed a series of three full pipetting cycles (apply tip, aspirate, dispense, tip ejection)
• On/Off Test – Test subjects completed a series of 12 applications of the tip followed by tip ejection
• Step-by-step sequence of tip application, aspiration, dispense and tip ejection
For this comprehensive study, five different brands of pipettors and seven different brands of pipette tips were evaluated in two different test groups. In the "Custom" group, brand name tips were paired with their corresponding brand name pipettors in the force measurements. In the "Generic" group, pipettors and tips were mixed and matched between brands to compare forces among the universal fit tips. Biotix, a universal fit tip, was tested with each pipettor and compared against data from both groups.
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Figures 4 and 5. (Click each chart to enlarge)
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Study Results
The results of the study showed significant and measurable differences in force exertion, user perceptions and fatigue potential. Overall, the ergonomic performance of the Biotix tips based on the EMG measurements and the user perception was best among the tested products. Measurements taken from the EMG recordings clearly demonstrate lower total muscle work overall during a standard pipetting cycle as compared to custom and generic tip brands (Fig. 4).
Summary
Ergonomic testing indicated significant differences in the factors associated with measured insertion/ejection forces, fatigue potential and user perceptions. Overall, the ergonomic performance of the Biotix tips was the best among the products tested, and was the most preferred among test subjects (Fig. 5). Biotix pipette tips demonstrate ergonomic benefits across a broad range of pipettors, and provide end-users interested in adopting ergonomic programs a greater selection of pipettor choice.
Additional Information
To download a copy of this technical bulletin, visit: www.biotix.com/support/white-papers or contact Biotix: csr@biotix.com.
References
1. Bureau of Labor Statistics, U.S. Department of Labor, News Release - Workplace Injuries and Illnesses - 2009; Oct. 21, 2010. USDL-10-1451, pg. 2
2. Bureau of Labor Statistics, U.S. Department of Labor, News Release - Nonfatal Occupational Injuries and Illnesses Requiring Days Away from Work, 2009; Nov 9, 2010. USDL-10-1546, pg. 6
3. Bjorkstein, M., et al: Applied Ergonomics 1994; 25(2): 88-94
4. Hoskins, D., et al: Laboratory Ergonomics, the Wake-up Call: A Case Study; Chemical Health & Safety Jan/Feb 1998, 5(1), 20-23, 38