Date of Award

Spring 2019

Degree Type


Degree Name

Master of Science (MS)


Industrial Hygiene

Committee Chair

Roger Jensen

First Advisor

Lorri Birkenbuel

Second Advisor

Theresa Stack

Third Advisor

Liping Jiang


A major concern in the field of occupational safety and health is the fatalities resulting from falling from heights. In the construction industry, a common approach for protecting workers is the use of a fall protection harness connected to a secure anchor. To be effective, harnesses must be fitted and adjusted to the individual. This requires training on adjusting the straps of a harness, and the training must include practice to ensure the worker has the skills to make a secure fit. It would be useful for those who conduct training on harness fitting to know if trainees would benefit from more than one practice donning a harness and adjusting the straps.

The broad hypothesis for this study is that the repetition times for donning a harness to attain a satisfactory fit will be, after proper training and familiarity with the harness, longer on the initial repetition, and reduced each subsequent repetition. The reduction pattern is expected to follow the common learning curve model.

The specific aim of this project was to experimentally characterize how the time to don and adjust a harness changes with number of repetitions. A secondary intent was to obtain qualitative feedback about usability of harness fitting straps. The time to properly adjust the straps was used as an indicator of how skill level changes with additional repetitions. A repetition was defined for this project as donning and adjusting the harness with coaching by the trainer. General donning strap guidelines and visual observations by the trainer were used to help each trainee fit their harness according to the manufacturers’ guidelines.

Twenty-five college students participated in a study by performing each of five steps in a harness-donning repetition. Each participant repeated the process four times while being timed. After each repetition the participant received tips from the experimenter. This approach was used to mimic the harness-fit training used in the construction company where the investigator interned.

Results showed reduced donning times with each repetition. The largest mean decrease was from the first to second repetition. Times continued to decline each repetition, with time reductions getting smaller with each repetition. The pattern of declining time followed a learning curve based on a power model. According to the fitted model the time will decrease 20.6% with each doubling of repetitions; thus, the second repetition will take 20.6% less time than the first, and the fourth repetition will take 20.6% less time than the second.


A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Industrial Hygiene