Effects of Added Weight and Girth on Static Strength
Open Access
- Author:
- Jankiewicz, Susan Lynn
- Area of Honors:
- Industrial Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Andris Freivalds, Thesis Supervisor
Dr. Paul M Griffin, Thesis Honors Advisor - Keywords:
- Lifting
Obesity - Abstract:
- The rise of obesity is a challenge our world is facing today. In the workplace the National Institute of Occupational Safety and Health (NIOSH) has outlined guidelines for the recommended weight a person should not exceed when lifting an item repeatedly throughout the work day (United States, 1994). One of the limitations of the 1991 lifting guidelines is that it does not account for a different body structure, such as obesity (Blosser, 2007). The purpose of this research is to compare the lifting capacities of the normal, overweight, and obese weight groups as well as determine if it is the added weight, added girth, or the added weight and girth that contributes to the change in lifting capacity. During the experiment the lifting capacity, using the leg and then torso muscles, of the participants was measured. Next, the participants completed the maximum acceptable weight of lifts (MAWL), which determined the maximum amount they would be comfortable lifting every 15 seconds during an eight hour work day. Phase 2 of the experiment was completed by the normal weight category participants. They were asked to perform the lifts again but with a 19.7 pound weight vest on, a pregnant belly, and then with both on. The weight vest simulated added weight and the pregnant belly simulated added girth. These procedures follow the protocol developed by Lorna Cintron (2012). The results of the experiment showed that in Phase 1, gender, height, and weight were used to predict the lifting capacity using the leg and torso muscles. The regression model for the leg muscles had an R-squared value of 49.5% and the torso muscles had an R-squared value of 57.1%. The MAWL model produced an R-squared value of 37.7%, using the gender and leg average, which is worse than the previous models due to the subjective nature of the test. Phase 2 found that the added weight and girth were not significant factors in the regression model for the leg average, which produced an R-squared value of 54.1%. In contrast, the regression model for the torso average found that the added weight, girth, gender, and height were significant with an R-squared value of 60.7%. It was then determined that the extra weight on the back impacted the individual’s ability to lift with their torso muscles. This research and two other studies have looked at the impact of obesity on lifting capabilities, but more research needs to be completed to prevent individuals in the workplace from developing lower back pain or injuring themselves on the job or outside of work.