Raoul Grönqvist's research while affiliated with Centers for Disease Control and Prevention and other places

... Slipping and falling are responsible for a great amount of injury expenditures in the workplace globally [1,2,3,4,5]. Slipping and falling are also major contributors to civilian casualties and injuries especially for older adults [6,7,8]. ...

... From a fluid lubrication perspective, a liquid film between two sliding surfaces being pressed together becomes pressurized, which causes the surfaces to stay separated and the coefficient of friction to decrease. Fluid pressures can develop due to both a wedge effect (3,(13)(14)(15)(16) and a squeeze-film effect (3,15,17,18). The wedge effect captures how fluid pressure varies with sliding velocity and fluid viscosity, whereas the squeeze-film effect captures how fluid pressure diminishes over time. ...

... p assessment tool' based on the measurement of surface micro-roughness. Interestingly, most manufacturers of the chemical treatments claim that their product generates roughness at the micro-level. Surprisingly, there are very few investigations of the impact of these chemical treatments on the slip resistance and roughness of glazed ceramic tiles. Grönqvist et al., (1992 Grönqvist et al., ( , 2003) reported a significant increase of the wet friction of a glazed ceramic tile after a treatment with a solution of ammonium bifluoride at 5% in water. The increase in wet friction was accompanied by an increase of the micro-roughness. Bowman et al., (2002) report friction measurements with various methods on a ...

... An abrupt decrease in the under-shoe friction during different gait activities, such as walking or running, is the primary reason for initiation of unintentional slips [12][13][14]. The traction available at the interface between shoe and walking surface can be quantified by calculating the available coefficient of friction (ACOF) [15,16]. These sudden changes in the ACOF are generally due to footwear outsole design, presence of slippery contaminants, type of flooring, or all of them [17][18][19][20][21][22][23]. ...

... They concluded that Ra may be adopted as one of the predictors of the perceived floor slipperiness of human participants. Grönqvist et al. [39] measured the dynamic COF of floor samples with varying floor roughness. The COF and Ra of their floor samples were highly correlated (r = 0.87, p < 0.001) with each other. ...

... Once hydroplaning occurs, tires will completely lose their drive and braking forces [8]. Similarly, walking with rubber soles on wet or icy surfaces leads to similar problems [9]. Typical examples of making full use of the squeeze film effect are squeeze film dampers and vibro-tactile texture reproduction techniques. ...

... Sudden movements and loading are important factors in the etiology of low back pain ( Manning et al., 1984;Magora, 1973). Sudden movements often occur in occupational settings (Hirvonen et al., 1996;Andersen et al., 2001). During lifting, sudden movements and loading may occur when people estimate the mass of the object incorrectly. ...

... Acidentes de queda da própria altura podem ocasionar lesões, fraturas ou mesmo óbitos, eventualmente, sendo responsáveis por grandes perdas econômicas e sofrimento humano 1 . Dentre as diversas causas que podem desencadear esse tipo de acidente, destaca-se o escorregamento em superfícies lisas, bastante recorrente em ambientes domésticos, laborais e públicos. ...

... Existing field-based (portable) tribometers possess meaningful reliability for measuring friction properties such as slip resistance. These include horizontal pull slipmeters [14], portable articulated strut tribometers [15], British portable skid testers [16], tortus devices [17], portable inclineable articulated strut tribometers [18], and cart-type friction measurement devices [19]. However, it is sometimes difficult to introduce tribometers into the workplace because of their portability, handleability, expense, and time costs. ...

... Several studies have reported that firefighters' MSDs are influenced by heavy and bulky personal protective equipment Shitan Wang: https://orcid.org/0000-0002-6619-8908 (PPE) [6,7]. The PPE consists of turnout garments, self-contained breathing apparatus (SCBA), fire boots, helmet, and gloves, adding a significant physical burden during firefighting and leading to restricted mobility and musculoskeletal injuries in different body regions. ...