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Coefficient of friction, walking speed and cadence on slippery and dry surfaces: shoes with different groove depths
Objective. The present study aimed to determine the coefficient of friction (COF), walking speed (WS) and cadence while walking on slippery and dry surfaces using shoes with different sole groove depths to predict likelihood of fall. Background. Design of shoe sole groove is crucial to prevent slipping during walking. Methods. 22 healthy young men (mean age 24.5, body mass index 22.5) volunteered for this semi-experimental study. Six different conditions of the test (combination of three shoes and two surfaces) were defined and the condition was repeated three times. In total, 396 trials (22 subjects × 3...
Predictive multiscale computational model of shoe-floor coefficient of friction
Understanding the frictional interactions between the shoe and floor during walking is critical to prevention of slips and falls, particularly when contaminants are present. A multiscale finite element model of shoe-floor-contaminant friction was developed that takes into account the surface and material characteristics of the shoe and flooring in microscopic and macroscopic scales. The model calculates shoe-floor coefficient of friction (COF) in boundary lubrication regime where effects of adhesion friction and hydrodynamic pressures are negligible. The validity of model outputs was assessed by...
Factors affecting fall severity from a ladder
Impact of climbing direction, gloves, gender and adaptation Ladder falls cause many fatal injuries. The factors that affect whether a ladder perturbation leads to a fall are not well understood. This study quantified the effects of several factors on a person's ability to recover from a ladder perturbation. Thirty-five participants each experienced six unexpected ladder missteps, for three glove conditions (bare hands, high friction, low friction) and two climbing directions (ascent, descent). Fall severity was increased during ladder descent (p < 0.001). Gloves did not affect fall severity...
Efficacy of a rubber outsole with a hybrid surface pattern for preventing slips on icy surfaces
Conventional winter-safety footwear devices, such as crampons, can be effective in preventing slips on icy surfaces but the protruding studs can lead to other problems such as trips. A new hybrid (rough and smooth) rubber outsole was designed to provide high slip resistance without use of protruding studs or asperities. In the present study, we examined the slip resistance of the hybrid rubber outsole on both dry (-10 °C) and wet (0 °C) icy surfaces, in comparison to three conventional strap-on winter anti-slip devices: 1) metal coils ("Yaktrax Walker"), 2) gritted (sandpaper...
Perceived risks for slipping and falling at work during wintertime and criteria for a slip-resistant winter shoe among Swedish outdoor workers
The leading cause of work related accidents in Sweden is falls. Many slips and falls occur on icy and snowy surfaces, but there is limited knowledge about how to prevent accidents during outdoor work in winter conditions. The purpose of this study was to describe risk factors of slips and falls and criteria for slip-resistant winter shoes from a user perspective. The result is based on focus group interviews with 20 men and women working in mail delivery, construction and home care in Sweden. The data was analyzed with qualitative content analysis. Risk factors described were related to physical...
Predicting the probability of slip in gait
Methodology and distribution study The likelihood of a slip is related to the available and required friction for a certain activity, here gait. Classical slip and fall analysis presumed that a walking surface was safe if the difference between the mean available and required friction coefficients exceeded a certain threshold. Previous research was dedicated to reformulating the classical slip and fall theory to include the stochastic variation of the available and required friction when predicting the probability of slip in gait. However, when predicting the probability of a slip, previous researchers...
Duration of slip-resistant shoe usage and the rate of slipping in limited-service restaurants
Results from a prospective and crossover study Several studies have indicated that slip-resistant shoes may have a positive effect on reducing the risk of slips and falls, a leading cause of injury at work. Few studies, however, have examined how duration of shoe usage affects their slip-resistance properties. This study examined the association between the duration of slip-resistant shoes usage and the self-reported rate of slipping in limited-service restaurant workers. A total of 475 workers from 36 limited-service restaurants in the USA were recruited to participate in a 12-week prospective...
Contribution of gait parameters and available coefficient of friction to perceptions of slipperiness
Perceived slipperiness rating (PSR) has been widely used to assess walkway safety. In this experiment, 29 participants were exposed to 5 floor types under dry, wet and glycerol conditions. The relationship between their PSR and objective measurements, including utilized coefficient of friction (UCOF), gait kinematics and available coefficient of friction (ACOF), was explored with a regression analysis using step-wise backward elimination. The results showed that UCOF and ACOF, as well as their difference, were the major predictors of the PSR under wet and glycerol conditions. Under wet conditions...
Development of a High Slip-resistant Footwear Outsole Using a Hybrid Rubber Surface Pattern
The present study examined whether a new footwear outsole with tread blocks and a hybrid rubber surface pattern, composed of rough and smooth surfaces, could increase slip resistance and reduce the risk of fall while walking on a wet floor surface. A drag test was performed to measure static and dynamic coefficient of friction (SCOF and DCOF, respectively) values for the footwear with the hybrid rubber sufrace pattern outosole and two types of commercially available boots that are conventionally used in food factories and restaurant kitchens with respect to a stainless steel floor covered with...
Temporal changes in the required shoe-floor friction when walking following an induced slip
Biomechanical aspects of slips and falls have been widely studied to facilitate fall prevention strategies. Prior studies have shown changes in gait after an induced slipping event. As such, most researchers only slip participants one time to avoid such changes that would otherwise reduce the external validity of experimental results. The ability to slip participants more than once, after allowing gait to return to a natural baseline, would improve the experimental efficiency of such studies. Therefore, the goal of this study was to characterize the temporal changes in required shoe-floor friction...
Perceived floor slipperiness and floor roughness in a gait experiment
BACKGROUND: Slips and falls contribute to occupational injuries and fatalities globally. Both floor slipperiness and floor roughness affect the occurrence of slipping and falling. Investigations on fall-related phenomena are important for the safety and health of workers. OBJECTIVE: The purposes of this study were to: compare the perceived floor slipperiness before and after walking on the floor; compare the perceived floor slipperiness with and without shoes for males and females; discuss the perceived floor roughness based on barefoot walking; and establish regression models to describe the relationship...
Slip-related characterization of gait kinetics
Investigation of pervious concrete as a slip-resistant walking surface Slip-related falls are a significant health problem, particularly on icy walking surfaces. Pervious concrete, a material allowing rapid exfiltration of melted ice from the walking surface, may help reduce slipping risk. Therefore, the purpose of this study was to compare slipping characteristics of traditional and pervious concrete walking surfaces in icy conditions using kinetic biomechanical analyses. We hypothesized that pervious concrete, in comparison to traditional concrete, would be characterized by less severe ice-related...
Optimisation of the mechanical slip resistance test for footwear used in EN ISO 13287:2007 - Follow on study
The measurement of the slip resistance of footwear is inherently difficult due to the complexity of the human gait, which leads to changing values of the biomechanical parameters during the walking step. Only some steps result in a slipping heel, which compounds the difficulty in identifying the values of the parameters that need to be simulated. A number of studies have attempted to measure the parameters of walking and/or a slip, in order that realistic values can be incorporated into tests attempting to replicate the slip process. Source : http://www.hse.gov.uk/research/rrpdf/rr951.pdf
Slips and trips new tools disponible
HSE (UK) explains how to prevent slips and trips in the workplace. Looks at the causes of slips and trips and discusses how to prevent them. A new «Shattered Lives» website, specialist e-learning tools: STEP (Slips and Trips elearning Package) and a new e-tool, WAIT (Work at height Access equipment Information Toolkit) have received 33 000 new visitors. Source: Slips and trips. Health and Safety Executive, August 2012. http://www.hse.gov.uk/slips/ Voir Aussi: Slips, trips and falls are preventable and everybody has a role to play. The HSA «Get a grip» document (Ireland)...
Over-treating tiles with 10 times the amount of hydrofluoric acid normally used leads to more slip resistant surface
There are many anti-slip treatments that claim to reduce the risk of slips and falls. In a previous investigation, it was shown that the normal treatment of smooth and glazed ceramic tiles with an aqueous solution of hydrofluoric acid increased only slightly the dry and wet friction and the average roughness but made the tiles more fragile and more difficult to clean. This article reports the impact of multiple cycles of hydrofluoric acid treatment and abrasive wear and the impact of over-treating the tiles with 10 times the amount of hydrofluoric acid normally used. The overtreatment removes more...
A field assessment of floor slipperiness in a student cafeteria
Investigation of floor slipperiness is critical in studying the risk of slips and falls. This research conducted friction measurements and employee survey on floor slipperiness in a student cafeteria in a university in China in order to study the correlation between the two types of floor slipperiness measure. It was found that the fryer area in kitchen 1 and the meat defrost sink in kitchen 2 had significantly the lowest coefficient of friction (COF) values among all areas in the same kitchen. The results showed that the levels of friction on the floors in different areas in each kitchen were...
Development of new footwear sole surface pattern for prevention of slip-related falls
In this study, a new rubber surface pattern for a footwear sole was developed to prevent slip-related falls. This pattern shows a high static coefficient of friction (SCOF) and a high dynamic coefficient of friction (DCOF) when sliding against a liquid contaminated surface. A hybrid rubber block, in which a rubber block with a rough surface (Ra = 30.4 μm) was sandwiched between two rubber blocks with smooth surfaces (Ra = 0.98 μm), was prepared. The ratio of the rough surface area to the whole rubber block surface area r was 0%, 30%, 50%, 80%, and 100%. The coefficient of friction of the...
Assessment of slip resistance under footwear materials, tread designs, floor contamination, and floor inclination conditions
Slip and fall incidences are common in our daily lives. They are not only important environmental safety issues but also important occupational safety and health problems. The purpose of this study was to use the Brungraber Mark II to measure the friction so as to investigate the effects of the shoe sole, surface condition and the inclined angle of the floor and their interactions on friction coefficient. The results of the study showed the effects of all the main factors and their interactions were significant (p<0.001). Engineering designs & ergonomic interventions in slip & fall prevention...
Identifying Risk Factors of Falls among B.C.’s Healthcare Workers
This study examined data on workplace falls among healthcare workers in a large B.C. health region, to identify the factors leading to fall related injuries and report the associated compensation costs and days lost from work. Monitoring workplace falls in healthcare is critical to understanding the size of the problem, characterizing trends, estimating the economic burden, improving knowledge among health professionals, policy makers and the workers, and designing, implementing and evaluating appropriate interventions. Source : http://www.worksafebc.com/contact_us/research/research_results/res_60_10_750...
Footwear and modifications to goods vehicles in the UK road haulage sector
The central aim of this survey was to produce a set of baseline data, based on the opinions of HGV drivers, that described practices within the UK road haulage sector relating to slip, trip and falls risk factors. The survey explored risk factors relating to footwear and vehicle safety fittings eg ladders, steps, handrails and load bed covering. The research employed face-to face sample survey methodology that allowed reasonable generalisation to the UK population of HGV drivers. Source : http://www.hse.gov.uk/research/rrhtm/rr793.htm

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