Industrial machines which use vertical reciprocating motions in repetitive tasks are often operated by foot controls. Included among these machines are mechanical power presses, resistance welders, press brakes, sheet metal shears and riveting machines. A high percentage of machine operator injuries occur when a foot control is inadvertently depressed while the operator is reaching into a danger point to reposition a workpiece or to adjust the equipment. Using occupational injury statistics, workplace observations and a review of selected literature, a model of inadvertent use of foot controls is proposed and presented with the aid of two diagrams. One of the diagrams shows the operators foot movement coordinated with the hand movement, the other represents a sequence when coordination between hand and foot movement is interrupted. The proposed model was used for conducting machine safety simulation experiments in a metal products manufacturing establishment. It was found that the primary causes for inadvertent actuation of foot controls were: unmediated hand movements in response to workpiece or machine problems, mental slips associated with the normal task rhythm, and loss of operator balance. The authors suggest that to avoid injury, automated or hand control devices could be considered in lieu of foot controls. Alternatively, if foot control is selected, safeguarding devices which are difficult to circumvent could be used at the point of danger.