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The purpose of this study was to determine if differences exist in angle-specific torque, torque-velocity relationships, and power-velocity relationships of the quadriceps femoris muscle group when the trunk was and was not stabilized and the starting position was varied. We calculated isokinetic torques from seven adult men while the trunk was and was not stabilized for nine combinations of velocity of movement 0, 30, and 105 degrees/sec) and starting position (40, 60, and 100 degrees of knee flexion). The results suggest that peak angle-specific torques and instantaneous power are greater when the trunk is stabilized, the increase in the trunk-stabilized torque and power was greater at the higher velocity and for the larger ranges of motion, and the testing movement should not begin beyond 30 degrees of the angle of interest.

The problems associated with hazardous materials control are numerous and complex. One of these problems involves selecting hand protection which will resist permeation for the duration of the exposure while maintaining sufficient levels of dexterity and tactility so that the worker can safely and efficiently perform the required task.This study investigated the effect of nine glove combinations on manual dexterity. These included three single glove and six double glove combinations plus the bare hand condition. The subjects performed a nut-bolt-washer assembly-dissassembly task using the Bennett Hand Tool Dexterity Test apparatus. The task required the use of a screw driver, two sizes of open-end wrenches, and an adjustable wrench, along with handling the bolt, nut, and washer while performing the assembly-disassembly task for three different bolt, nut, and washer sizes (1/2", 5/16", 1/4").The response variables measured in the experiment were the time to complete each task and number of errors committed during each task. any of the items handled. model and the Duncan's Multiple Range Test. analysis. The results of the analyses showed that gloves increased the average completion time by 15 to 37%. Several double gloving combinations had significantly longer task completion times compared to single gloves.

This paper describes the theoretical basis upon which a test system has been set up to evaluate the sampling error associated with in-facepiece sampling on half-mask respirators. The in-facepiece sampling technique evaluated in this study is the one currently used in the U.S. to conduct quantitative facepiece fit testing. An experimental design was developed to study the sampling bias associated with in-facepiece sampling when selected parameters of the man/respirator system were varied. The results indicated that significant errors can be made in estimating concentration within a respirator when the current in-facepiece sampling technique is employed. Sampling bias was determined when in-facepiece samples were collected only during the inhalation phase of the respiratory cycles. They were found to range from greater than -99% to greater than +98%. The mean sampling bias was -17 +/- 38%. When measured in-facepiece concentrations were used to calculate a fit factor the resulting range was 44 to 4728 even though the actual fit factor was only 87. Based upon the data presented, it was hypothesized that faceseal leakage was streamlining within the respirator cavity. As a result, quantitative facepiece fit data on half-mask respirators may be biased by the large measurement error.