Measurements of trackways as a method for assessing locomotion in dairy cows

The aim of this study was to assess whether locomotion parameters obtained by measurements of cow trackways are reliable and sufficiently sensitive to describe locomotion in non-lame and lame dairy cows on different floors. Thirty-two non-lame cows were used to study the reliability of the trackway measurements. The cows were tested twice over three weeks and measurements from four consecutive strides were used during each test session. To study the effect of different floors on locomotion, 25 non-lame cows and eleven cows with different lameness degrees were tested on five different surfaces: solid and slatted concrete, both with and without 20 mm thick elastic rubber mats, and wet, compacted sand. The reliability of the measurements varied from moderate to low, with measurements relating to inter-limb coordination being most inconsistent. The slippery slatted concrete floor caused restricted locomotion in so far as the strides were significantly shorter here than on all the other floors. Use of yielding rubber mats resulted in a locomotion more similar to that on the sand path. Lameness had an effect on shortening strides and steps, but in most cases the animals’ reaction to different floorings was similar in lame and healthy cows. Step asymmetry due to lameness was decreased when cows walked on the soft surfaces. It was concluded that a trackway measurement system is a suitable method to use in field locomotion studies and that the system is useful in identifying differences in kinematics on different floor types. Since there is a relatively high inconsistency in cow walking it is beneficial to use measurements of several strides to obtain a representative gait pattern

Slips, Trips, and Falls: A Call to Duty

Slips, trips, and falls are a problem globally. Safety and health professionals must work diligently to protect workers and the public from injury. Property owners and/or occupants have a duty to mitigate hazards and reduce or eliminate risks of injury to visitors, customers, or travelers. Older workers and citizens are at greatest risk. Many types of hazards and conditions have been identified that increase the chances of pedestrian slip, trip and fall injuries. Common indoor hazards include slippery floors due to wax, water, tracked in snow and/or ice, spills, loose carpets or mats, uneven flooring, transition areas, raised edges, worn flooring, or items left on the floor such a cords, tools, equipment, unused material or waste. In the outdoor environment, and in cold climates snow and ice, are the major hazards associated with slips, trips, and falls and should be addressed immediately. Additional outdoor hazards are uneven surfaces, objects, potholes, mud, water, and debris from natural sources or human activity. Preventing slips, trips, and falls can be as simple as evaluating the hazards, determining risks, identifying controls, implementing controls and prevention strategies, and evaluating effectiveness to reduce the burden of slip, trip, and fall injuries and fatalities

A Study of Walkway Safety and Evaluation of Tribological Test Equipment

A walkway tribometer measures the coefficient of friction between flooring material and a test foot. The value of the coefficient of friction is an indicator as to whether the flooring surface is slippery and has a propensity to cause slip and falls. This study determined that one style of tribometer, an XL Tribometer, mimics the heel-to-floor interaction of the human heel strike. High speed video footage revealed that the test foot strikes the surface and rotates so that full engagement occurs before sliding thus mimicking the affect of a human ankle. The test foot accelerates forward as would be expected during a human slip event. The manufacturer’s reported impact speed of 11 in/s, when set to the operating pressure of 25psi, was found to be much lower than measured speeds of three calibrated tribometers. Three XL tribometers were tested and provided a range of impact speeds from 17.4 to 22.7 in/s (n=540) when set to the operating pressure of 25 psi. The pressure setting was found to have a significant effect on the impact speed while the mast angle had an insignificant affect. A review of human walking studies revealed a range of pedestrian heel impact speeds on the order of 19.4 to 45.3 in/s during normal human ambulation activities. These tribometers fell on the low side of this speed range. A sensitivity study showed that the measured value of the coefficient of friction tends to decrease with a higher impact speed. This COF decrease was on the order of 0.02 and below the machine resolution and considered inconsequential within the walkway safety community

Lower extremity preventive measures for slips: joint moments and myoelectric analysis

This study investigated the lower extremity preventive measures for slips on simulated slippery surfaces in construction worksites. A total of 15 harnessed Chinese males walked without slips on a 5-m walkway in 16 simulated conditions 10 times at their natural cadence. Joint moments were calculated from kinetics, kinematics and anthropometric data recorded from a force plate, a Novel Pedar system and a motion analysis system. Data were evaluated from footstrike to mid-stance at 10%-stance intervals. Electromyography signals from tibialis anterior, gastrocnemius, rectus femoris and biceps femoris in one stride were evaluated in four phases, including early/late stance and swing. Results showed that lower extremity preventive measures for slips included prolonged ankle plantar flexion moments from 25% to 92% stance, increased ankle plantar flexion moments from 30% stance to mid-stance, and diminished knee extension moments from 10% to 30% stance. Higher activity of rectus femoris and gastrocnemius were found in the late stance and the swing phase respectively

Lower-extremity gait kinematics on slippery surfaces in construction worksites

Purpose: The purpose of this study was to investigate the lower-extremity kinematics when walking on potentially slippery surfaces in simulated construction worksite environments. Methods: A survey was conducted to select two types of footwear, two floorings, and four contaminants to represent the local construction worksite environments, making 16 simulated conditions. A mechanical slip-resistance test was conducted to evaluate the slipping potential of the 16 conditions by the value of the dynamic coefficient of friction. The 16 conditions were classified into three groups by slipping potential. Fifteen harnessed Chinese male subjects were instructed to walk and avoid slips on each of the 16 simulated 5-m walkways 10 times at their natural cadence. The movements in the sagittal plane were videotaped, digitized, and analyzed by a motion analysis system. Gait pattern parameters were obtained. Lower-extremity kinematic data were time-normalized from foot strike (0% stance) to take-off (100% stance) and were extracted from foot strike to midstance (50% stance) at 10% stance intervals. Results: ANOVA showed that with increased slipping potential, changes in gait pattern parameters included increased stance and stride time, shortened stride length, decreased propagation speed, and gentle heel strike. In lower-extremity kinematic parameters, significant differences were found mainly at the ankle joint rather than the knee joint. Conclusion: Strategies to prevent slips included increased stance and stride time, shortened stride length, decreased propagation speed, and gentle heel strike. The ankle joint played the most important role in adaptation strategy. Such strategy included reducing range of motion, maintaining a stiff joint, and achieving flatfoot landing or a plantarflexed ankle joint during the first 10% stance

J Appl Biomech

Footwear plays an important role in worker safety. Work boots with safety toes are often utilized at mine sites to protect workers from hazards. Increasingly, mining operations require metatarsal guards in addition to safety toe protection in boots. While these guards provide additional protection, the impact of metatarsal guards on gait are unknown. This study aimed to measure the effects of 4 safety work boots, steel toe, and steel toe with metatarsal protection in wader- and hiker-style boots, on level and inclined walking gait characteristics, during ascent and descent. A total of 10 participants completed this study. A motion capture system measured kinematics that allowed for the calculation of key gait parameters. Results indicated that gait parameters changed due to incline, similar to previous literature. Wader-style work boots reduced ankle range of motion when ascending an incline. Hip, knee, and ankle ranges of motion were also reduced during descent for this style of boot. Wader-style boots with metatarsal guards led to the smallest ankle range of motion when descending an inclined walkway. From these results, it is likely that boot style affects gait parameters and may impact a miner's risk for slips, trips, or falls.CC999999/ImCDC/Intramural CDC HHSUnited States/2022-01-24T00:00:00Z32707563PMC785537410846vault:3720

Slip resistance of winter footwear on snow and ice measured using maximum achievable incline

Protective footwear is necessary for preventing injurious slips and falls in winter conditions. Valid methods for assessing footwear slip resistance on winter surfaces are needed in order to evaluate footwear and outsole designs. The purpose of this study was to utilise a method of testing winter footwear that was ecologically valid in terms of involving actual human testers walking on realistic winter surfaces to produce objective measures of slip resistance. During the experiment, eight participants tested six styles of footwear on wet ice, on dry ice, and on dry ice after walking over soft snow. Slip resistance was measured by determining the maximum incline angles participants were able to walk up and down in each footwear-surface combination. The results indicated that testing on a variety of surfaces is necessary for establishing winter footwear performance and that standard mechanical bench tests for footwear slip resistance do not adequately reflect actual performance. Practitioner Summary: Existing standardised methods for measuring footwear slip resistance lack validation on winter surfaces. By determining the maximum inclines participants could walk up and down slopes of wet ice, dry ice, and ice with snow, in a range of footwear, an ecologically valid test for measuring winter footwear performance was established

Stepping over obstacles of different heights and varied shoe traction alter the kinetic strategies of the leading limb

This study aims to investigate the effects of shoe traction and obstacle height on friction during walking to better understand the mechanisms required to avoid slippage following obstacle clearance. Ten male subjects walked at a self-selected pace during eight different conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two different pairs of shoes (low and high traction). Frictional forces were calculated from the ground reaction forces following obstacle clearance, which were sampled with a Kistler platform at 960 Hz. All frictional peaks increased with increases in obstacle height. Low traction shoes yielded smaller peaks than high traction shoes. The transition from braking to propulsion occurred sooner due to altered control strategies with increased obstacle height. Collectively, these results provided insights into kinetic strategies of leading limb when confronted with low traction and high obstacle environments

IIE Trans Occup

BackgroundNo specific guidelines or regulations are provided by the Mine Safety and Health Administration for the use of inclined grated metal walkways in mining plants. Mining and other companies may be using walkway materials that do not provide sufficient friction, contributing to slip and fall injuries.PurposeThe purpose of this study was to determine if there are significant differences in the required friction for different grated metal walkways during walking in diverse conditions.MethodsThe normalized coefficients of friction were measured for 12 participants while walking up and down an instrumented walkway with different inclinations (0\uc2\ub0, 5\uc2\ub0, 10\uc2\ub0, 15\uc2\ub0, and 20\uc2\ub0) and with and without the presence of a contaminant (glycerol). Self-reported slip events were recorded and the required coefficients of friction were calculated considering only the anterior/posterior components of the shear forces. Additionally, the available coefficients of friction for these walkway materials were measured at the 0\uc2\ub0 orientation using a tribometer, with and without the presence of the contaminant, using a boot heel as well as Neolite as the test feet.ResultsThe number of slips increased when the inclination angle reached 10\uc2\ub0 and above. Of all materials tested, the diamond weave grating was found to have the best performance at all inclines and when contaminated or dry. A high number of slips occurred for the perforated grating and serrated bar grating at 20\uc2\ub0 when contaminated.ConclusionsResults of this study suggest that the diamond weave grating provides significantly better friction compared to serrated bar and perforated gratings, especially at inclines greater than 10\uc2\ub0.CC999999/Intramural CDC HHS/United States2016-01-15T00:00:00Z26779388PMC471484

Effect of floor condition on pig gait

Unhealthy legs and claws in pig production are a persistent problem, a primary reason for which seems to be inappropriate floor properties in the pig pen. Inadequate frictional properties or low coefficient of friction (COF) may result in slippery floors and slip injuries to pigs. This thesis presents basis of design criteria for pig house floors with the aim of minimising the number of claw disorders. Parameter values were determined by pig gait studies in a gait analysis laboratory, where the pigs walked a straight or a curved test aisle. The gait was recorded by a force plate and a perpendicularly placed digital video camera as the pigs walked the test aisle. The specific aims of the four studies included in the thesis were to: 1) characterise pig gait and describe the effect of clean and fouled floor conditions for pigs walking a line on solid concrete, walking a curve on solid concrete and walking a curve on rubber mat; 2) determine the utilised COF (UCOF) of the walking pigs and compare it with measured dynamic COF (DCOF); and 3) analyse pig slip in different floor conditions. A set of parameter values characterising pig gait in clean and fouled concrete floor conditions were obtained by kinematic and kinetic methods. The data showed that pigs walking a straight line adapted their gait to fouled floor conditions. Pigs were able to adapt to walking a curve in clean floor conditions but the observed adaptation was not enough for safe walking in fouled floor conditions, where UCOF exceeded DCOF. Walking a curve on fouled rubber mat gave better traction and reduced forward and backward slips by over 50% compared with walking a curve on fouled concrete. The discrepancy between UCOF and measured DCOF observed in the studies could be due to the friction measuring device underestimating the actual risk of slipping and falling in fouled floor conditions, especially when walking a curve. Additional studies are needed to provide pig producers with more detailed information, e.g. guidelines for required COF values in pig pen situations where the required motion and speed of motion are determined. An appropriate data set for COF measurements at farm level can bring safer and more slip-resistant floor solutions in the future