2. Richard Wells 1,2 (1) Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada (2) Centre of Research Expertise for the Prevention of Musculoskeletal Disorders (CRE-MSD)

3. 1.Understand the characteristics of gloves that increase fatigue and decrease prehensile performance 2.Apply these ideas to evaluate anti- vibration gloves 3.Apply these ideas to evaluate surgical gloves

5.  Glove is stiff  Glove reduces tactility  Glove changes effective size of hand  BUT how to determine which of these factors is important  The approach is to separate out these factors using multiple measures

6. Independent variable: hand covering  Gloves – specific glove used by power line maintainers made of the same material and shape and available in different sizes which only differed in thickness  Interdigital spacers – to mimic the spacing between fingers caused by the glove thickness between the digits

7.  Grip Force – grip dynamometer  Tactile Sensitivity – Von Frey hair test  Perceived Exertion – self report exertion on a 100-point rating scale  Surface EMG of seven forearm muscles.  flexor digitorum superficialis(FDS)  flexor pollicis longus (FPL)  flexor carpi radialis (FCR)  flexor carpi ulnaris (FCU)  extensor carpi radialis (ECR(B))  extensor carpi ulnaris (ECU)  extensor digitorum (ED)

8. Protocol/Participants  10 male and 10 female university students who were free of upper extremity injury or pain  Order randomized to control for any fatigue or learning effects

9.  Maximum Effort – ramping effort up to maximum and hold for 3 sec  Form a grip posture – used to estimate effort required to form the hand into power grip posture  Grip foam cylinder without causing foam to visibly compress  Maintain a fixed force – maintain 75-N grip force on the dynamometer for 5 sec using visual feedback via an oscilloscope

10.  Lift an object – grip the vertical arms of the dynamometer in a power grip and elevate without any horizontal movement to an approximate height of 20 mm  Grip size – dynamometer grip span was adjusted such that the thumb and tip of index finger lightly touched each other in a bare-handed relaxed grip

11. 1.Increasing glove thickness and finger spacing reduces maximum grip force

12. Thicker gloves increased grip force for a constant lifting task (safety margin?)

13.  Increases in glove thickness increased perceived exertion during performance of a constant submaximal grip force  Increases in glove thickness increased perceived exertion to create an unloaded grip posture

14.  Increases in glove thickness increased forearm muscle activation during performance of a constant submaximal grip force  Increases in glove thickness increased forearm muscle activation to create an unloaded grip posture

15.  Increases in glove thickness increased forearm muscle activation during performance of a constant submaximal grip force  Increases in glove thickness increased forearm muscle activation to create an unloaded grip posture

16.  Increased glove thickness reduced tactile sensitivity

17.  Increasing glove thickness made it impossible for the fingers to reach around and touch the thumb as in the bare hand condition  Adjusting the grip span to compensate for the effective increase of grip span incurred by wearing thick gloves decreased grip force output

18. b This load is present in all situations

19. Tactility on palmar surface Fit at fingertips Thickness between fingers Stiffness/ Resistance to bending Friction/texture on palmar surface Friction inside glove Fit Overall

20. steel

21.  Style:  Finger vs Fingerless  Vibration Dampening:  Air Bladder vs Sorbothane + Match glove to tool frequency  Age of glove:  Decrement in performance with age  Quality:  Adherence to ISO 10819 Glove Testing Standard  Trade-offs Vibration dampening material thickness Reduced tactility Increased grip force Increased vibration transmission VIBRATION Increased efforts to use glove HAND

23. Protection Cuts Punctures  Bare00  Single Latex++  Double Latex++++  Triple Latex++ ┤ ++  Orthopaedic Latex++++  Glove Liners  Woven++++  Non-woven +++++  Indicator gloves*++++  Overgloves++++ *But more cuts/punctures found during surgery http://en.wikipedia.org/wiki/Medical_glove

24. Dexterity  Latex gloves are recommended when manual dexterity and tactility are particularly important.  Neoprene and nitrile gloves typically have a lower elasticity and are less comfortable than latex Latex Allergy Options  Low-allergen gloves (but amount of latex is not usually stated on packaging),  Non-powdered gloves, as the cornstarch power in powdered gloves is an efficient allergen carrier.  Non-latex gloves, nitrile, vinyl, polyisoprene, vinyl(PVC) and neoprene.  BUT, latex gloves are more flexible and reseal more readily after minor punctures. Latex Neoprene Nitrile http://en.wikipedia.org/wiki/Medical_glove

25. 1.Understand characteristics of gloves in general that increase fatigue and decrease prehensile performance 2.Use these ideas to evaluate anti-vibration gloves 3.Use these ideas to evaluate surgical gloves

26.  Heather Carnahan  Kirsten Willms  Patricia Rosati  Kevin Hurley  EUSA  Shannon Hunt (nee Maracle)  Carrie Boyle  Workplace Safety and Insurance Board

27.  Willms, K*., Wells, R., and Carnahan, H. Determinants of force decrement in gloved power grip, Human Factors, 51:797-812, 2009.  Wells, R., Hunt, S. Hurley, K., Rosati, P. (2010) Laboratory assessment of the effect of heavy rubber glove thickness and sizing on effort, performance and comfort., International Journal of Industrial Ergonomics, 40:386-391.  Wells, R., Hunt, S, Rosati, P., Hurley, K. The effects of heavy electrical gloves on powerline maintainers' effort and performance: Opportunities for improvement, submitted to Applied Ergonomics  Hunt, S, Boyle, C and Wells, R. Comparison of five approaches to keeping power line maintainers’ hands warm during work in the cold, abstract for presentation at IEA2012  http://cre-msd.uwaterloo.ca/Position_Papers.aspx http://cre-msd.uwaterloo.ca/Position_Papers.aspx