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.