Subjective Self-Ratings of Perceived Difficulty during Obstructed Manual Hose Insertion Tasks

Objective: A study was conducted to measure the effect that restricted hand access had on perceived difficulty ratings during simulated hose insertion tasks. Background: Insertion tasks have been identified by workers as physically demanding. Spatial limitations around the flange may affect the ability of the workers to successfully perform the insertion task. Methods: Six male and six female subjects pushed a rubber hose onto a stationary flange under conditions of limited hand access during simulated insertions. Results: The highest difficulty ratings were recorded when an obstruction was lateral to the flange. The overall difficulty rating was positively correlated with posture and force ratings. Conclusion: The location and number of obstructions is an important factor in how the subjects perceived the difficulty of the task. Application: The results of this study can be applied to the future design of insertion-type tasks and methodologies for subjectively assessing hand clearance.