Barriers and Motivators for Tractor ROPS Retrofitting in Iowa.

Iowa State University Extension and Outreach conducted an assessment of Iowa farm operators' perceptions of the barriers and motivators when considering retrofitting tractors with rollover protective structures (ROPS). A statewide sample of approximately 2,000 farm operators was surveyed in the 2017 Iowa Farm and Rural Life Poll. A series of questions was asked to evaluate the importance of potential barriers to decisions to not retrofit a tractor and potential motivators that could influence the decision to retrofit or purchase a tractor with ROPS. The survey received a 48% response rate (999 responses). Among the 76% of Iowa farm operators who reported at least one pre-1985 tractor, only 18.6% reported that all of those tractors had ROPS. The remaining 81.4% had at least one tractor that did not have ROPS. Iowa farm operators' perceptions of the barriers and motivators when considering retrofitting tractors with ROPS are shared. The results of Iowa farm operators' perceptions will be used as Iowa State University Extension and Outreach prepares to align efforts with the National Tractor Safety Coalition and participate in the National ROPS Rebate Program, with the goal of reducing tractor fatalities.

Extraction Force Prediction for Male Entrapment Victims with Different Body Types Submerged below the Grain Surface.

One contributor to agriculture's high death rate is confined space fatalities caused by entrapment in grain. Over 1,000 grain-related fatalities have been documented by researchers in 43 states, and states with the largest grain storage capacities have been shown to experience a proportionally larger number of suffocation fatalities. Several researchers have measured extraction forces in specific conditions, but a reference standard is needed for estimating the extraction forces for grain suffocation victims in common conditions. A prediction model for estimating extraction forces was developed using the principle of boundary shear, an approximation of human surface area, and a commonly accepted equation for lateral granular pressure. This research reintroduces the prediction model for extraction forces and explores several sensitivity analyses of the input variables. It also updates the anthropometric data used in the model calculations and produces extraction force estimates for adult male victims with different body shapes submerged below the grain surface. Results from the prediction model are presented graphically for common input variables, various entrapment depths, and adult male body shapes.

Editorial: ROPS Are Not Homemade.

Safety professionals should speak up when secondary school teachers and FFA advisors consider fabricating and installing low-cost rollover protective structures (ROPS) as service learning projects for ag education students or as a service to the farm community. These projects are often motivated by the desire to address the continued occurrence of tractor rollovers, which are the most frequent cause of farm-related fatalities (NIOSH, 2018). These projects have also been made feasible by the availability of online plans for ROPS fabrication, including plans from the National Institute for Occupational Safety and Health (NIOSH) that are designed for specific makes and models of tractors. Because of the large number of older tractors that were not originally equipped with ROPS, and the cost and lack of easily accessible ROPS retrofits, fabricating a structure to provide operator protection in the event of an overturn can be attractive as a service learning project. In addition, several of the NIOSH Agricultural Injury Prevention Centers have promoted these projects as a means of reducing the frequency of rollover-related injuries. However, in light of the liability risk involved, such projects should be weighed carefully. Fabricating a ROPS is not the same as building a chicken house, fabricating a welding table, or welding together a hay feeder. ROPS are life-saving devices that must meet specific design and installation standards that exceed the expertise available in most secondary school ag education shops, and even most local machine shops. In fact, "ROPS" is a technical term defined by OSHA standards and the Society of Automotive Engineers (SAE). It does not apply-nor should it be applied-to untested, homemade structures that are installed on tractors with the intent of protecting the operator.

Estimating Passive Stress Acting on a Grain Entrapment Victim's Chest.

Grain entrapments remain a major concern in the grain industry, with 1,100 incidents documented since the 1970s. One particular concern is the ability of a victim to breathe while entrapped in grain. Anecdotal reports suggest that victims struggle to breathe when entrapped in grain to a depth that covers their chests, yet some evidence indicates that victims should be able to breathe normally as long as their airways are not blocked regardless of depth. The hypothesis for this discrepancy is that previously published experiments measured an active stress state in the grain, while a person breathing also experiences a passive stress state during inhalation. The passive stress is significantly larger than the active stress. The objective of this study was to measure the passive stress when pushing against grain, such as during inhalation, and compare it to active stress state measurements. An MTS Criterion testing machine, which is a force deformation testing device, was used to push a block horizontally against a column of grain and record the force and displacement during the movement. The measured passive stress was calculated from the force and displacement values and ranged from 9.4 to 11.0 kPa at a depth of 20 to 30 cm. These values are three to four times larger than previously published measurements of stresses at similar depths. This result indicates that the discrepancy between experimental results and anecdotal reports is most likely due to the type of stress state experienced in grain entrapment. Findings imply that the pressures on the victim's chest during entrapment are sufficient to cause breathing difficulties or crush/positional asphyxiation in some cases. A full-scale study is recommended.

Apparent Coefficient of Friction of Wheat on Denim.

Calculation of the extraction force for a grain entrapment victim requires a coefficient of friction between the grain and the surface of the victim. Because denim is a common fabric for the work clothes that cover entrapment victims, the coefficient of friction between grain and denim becomes necessary. The purpose of this research was to calculate the apparent coefficient of friction of wheat on denim fabric using a proven procedure. The expectation is to improve the current understanding of conditions that influence extraction forces for victims buried in wheat. The apparent coefficient of friction of wheat on denim fabric was calculated to be 0.167 with a standard deviation of ±0.013. The wheat had a moisture content of 10.7% (w.b.) and bulk density of 778.5 kg m-3. The apparent coefficient of friction of wheat on denim was not significantly affected by pull speeds of 0.004, 0.008, and 0.021 mm s-1 nor normal grain pressures of 3.2, 4.8, 6.3, 7.9, and 11.1 kPa. This is a beginning of understanding the conditions that influence the extraction forces for grain entrapment victims.

Agricultural Worker Injury Comparative Risk Assessment Methodology: Assessing Corn and Biofuel Switchgrass Production Systems.

Keeping workers safe is a continuing challenge in agricultural production. Risk assessment methodologies have been used widely in other industries to better understand systems and enhance decision making, yet their use in production agriculture has been limited. This article describes the considerations and the approach taken to measure the difference in worker injury risks between two agricultural production systems. A model was developed specifically for the comparison of worker injury risk between corn and biofuel switchgrass production systems. The model is composed of injury and exposure values that were used in a Monte Carlo simulation. The output of this risk assessment shows that approximately 99% of the values from the Monte Carlo simulation rank corn production as a greater worker injury risk than biofuel switchgrass production. Furthermore, the greatest contributing factors for each production system were identified as harvest, and that finding aligns with current literature.

Likelihood of Entanglement when Materials are Dropped Vertically onto a Rotating PTO Knuckle.

Power take-off (PTO) is a common method of transferring power from a tractor to a towed piece of machinery. The PTO is also a well-documented cause of severe and often permanent disabling injuries to farm operators. The physical conditions that cause entanglements are not well established. Several studies have explored the parameters of PTO entanglements as materials have been drawn across a rotating PTO knuckle to test for entanglement probability. The objective of this study was to determine probability of entanglement when materials are dropped vertically onto a PTO knuckle spinning at 540 rpm. A total of 360 randomized trials were conducted with ten replications for each of the six positions (center of yoke, edge of yoke rotating downward, edge of yoke rotating upward, center of cross, edge of cross rotating downward, and edge of cross rotating upward) and six different materials (woven cotton athletic shoe lace, cotton workboot lace, leather workboot lace, cotton twine, denim strip, and Tyvek strip). Not a single entanglement was recorded. Dramatic high-speed video imagery authenticated the material's motion and path as it interacted with the rotating PTO knuckle.

Contributing Causes of Injury or Death in Grain Entrapment, Engulfment, and Extrication.

OBJECTIVES: Grain entrapments and engulfments are one of most common hazards associated with grain storage facilities, with over 1,140 such entrapments/engulfments documented since the 1970s. The objective of the study was to determine the factors that contribute to injury or death in grain entrapment, engulfment, and extrication cases. METHODS: A literature review, including data contained in the Purdue Agricultural Confined Spaces Incident Database (PACSID), was conducted to determine the conditions that the body experiences during an entrapment or engulfment in grains and during extrication efforts. RESULTS: Based on the review, the conditions a human body faces during an entrapment, engulfment, or extraction can be split into two broad categories-environmental and physiological/psychological. The environmental factors depend on the grain's properties, depth of entrapment or engulfment, position of the victim's body, and characteristics of the storage unit, which include the grain's lateral pressure, vertical pressure, and weight, as well as friction, oxygen availability and diffusion rate, and grain temperature. The physiological and psychological factors are related to the individual's age and physical and psychological conditions, and manifest themselves in terms of oxygen consumption, asphyxiation (including aspiration, lack of oxygen, compression or splinting of the thorax), blood flow, and heart rate. CONCLUSION: Of all the above factors, a review of fatality data contained in the PACSID indicate that aspiration, asphyxiation, grain weight, and lateral pressure are most likely the primary cause of death for most entrapment victims. Research gaps found by this study include an understanding of the impact of lateral pressure on lung expansion and oxygen availability and consumption rate, and the need for more case studies to accurately determine cause of death.

Lower extremity joint moments during carrying tasks in children.

Farm youth often carry loads that are proportionally large and/or heavy, and field measurements have determined that these tasks are equivalent to industrial jobs with high injury risks. The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity joint moments during carrying tasks. Three age groups (8-10 years, 12-14 years, adults), three load amounts (0%, 10%, 20% BW), and three load symmetry levels (unilateral large bucket, unilateral small bucket, bilateral small buckets) were tested. Inverse dynamics was used to determine maximum ankle, knee, and hip joint moments. Ankle dorsiflexion, ankle inversion, ankle eversion, knee adduction, and hip extension moments were significantly higher in 8-10 and 12-14 year olds. Ankle plantar flexion, ankle inversion, knee extension, and hip extension moments were significantly increased at 10% and 20% BW loads. Knee and hip adduction moments were significantly increased at 10% and 20% BW loads when carrying a unilateral large bucket. Of particular concern are increased ankle inversion and eversion moments for children, along with increased knee and hip adduction moments for heavy, asymmetrical carrying tasks. Carrying loads bilaterally instead of unilaterally avoided increases in knee and hip adduction moments with increased load amount.

The effects of age and type of carrying task on lower extremity kinematics.

The purpose of this study was to determine the effects of age, load amount and load symmetry on lower extremity kinematics during carrying tasks. Forty-two participants in four age groups (8-10 years, 12-14 years, 15-17 years and adults) carried loads of 0%, 10% and 20% body weight (BW) in large or small buckets unilaterally and bilaterally. Reflective markers were tracked to determine total joint range of motion and maximum joint angles during the stance phase of walking. Maximum hip extension, hip adduction and hip internal rotation angles were significantly greater for each of the child/adolescent age groups as compared with adults. In addition, maximum hip internal rotation angles significantly increased when carrying a 20% BW load. The observation that the 8-10-year-old age group carried the lightest absolute loads and still displayed the highest maximum hip internal rotation angles suggests a particular necessity in setting carrying guidelines for the youngest children. STATEMENT OF RELEVANCE: Bucket-carrying tasks were analysed as a function of age group, load amount and load symmetry. Hip joint rotations significantly increased when carrying 20% BW loads and in children as compared to adults, which suggests a particular necessity in setting carrying guidelines for the youngest age group (8-10 year olds).

Upper extremity and lower back moments during carrying tasks in farm children.

Farm youth commonly perform animal care tasks such as feeding and watering. The purpose of this study was to determine the effects of age, bucket size, loading symmetry, and amount of load on upper body moments during carrying tasks. Fifty-four male and female participants in four age groups (8-10 years, 12-14 years, 15-17 years, and adults, 20-26 years) participated in the study. Conditions included combinations of large or small bucket sizes, unilateral or bilateral loading, and load levels of 10% or 20% of body weight (BW). During bucket carrying, elbow flexion, shoulder flexion, shoulder abduction, shoulder external rotation, L5/S1 extension, L5/S1 lateral bending, and L5/S1 axial rotation moments were estimated using video data. The 8-10 year-old group did not display higher proportional joint moments as compared with adults. Decreasing the load from 20% BW to 10% BW significantly decreased maximum normalized elbow flexion, shoulder flexion, shoulder abduction, shoulder external rotation, L5/S1 lateral bending, and L5/S1 axial rotation moments. Carrying the load bilaterally instead of unilaterally also significantly reduced these six maximum normalized joint moments. In addition, modifying the carrying task by using smaller one-gallon buckets produced significant reductions in maximum L5/S1 lateral bending moments.