Unit VII Course Project Final
docx
keyboard_arrow_up
School
Columbia Southern University *
*We aren’t endorsed by this school
Course
5302
Subject
Industrial Engineering
Date
Feb 20, 2024
Type
docx
Pages
10
Uploaded by DeanMinkMaster696
Unit VII Course Project
June A. Warren-Pope
Columbia Southern University
Advanced Ergonomics
OSH 6301
Professor Edem Tetteh
January 9, 2024
2
Ergonomic Assessment Report
1. Task Description
The worker in the video is outside in the woods leaning down and picking up pieces of wooden logs, placing them onto an electric saw, cutting the wood lengthwise, and then throwing the wood into a pile on the side. The outdoor environment is characterized by uneven terrain, varying lighting conditions,
and ambient noise. The work layout comprises a designated area for cutting logs and a designated area for stacking the cut logs off to the side. The tools employed include a large chainsaw for cutting logs.
The work environment poses challenges due to the uneven ground, potentially leading to unstable footing during log lifting. Inadequate lighting might result in reduced visibility, increasing the risk of tripping or encountering obstacles. Furthermore, the exposure to ambient noise could lead to distraction and communication difficulties among workers.
2. Identification of MSD Risk Factors
For assessing MSD risk factors, the chosen evaluation tool is the Rapid Upper Limb Assessment (RULA). The tool evaluates factors such as posture, force exertion, repetition, and vibration. Applying RULA to the task, it is evident that workers frequently engage in awkward postures while lifting logs and operating chainsaws. These postures, combined with the exertion of force, elevate the risk of developing
musculoskeletal strain and discomfort. The repetitive nature of lifting and transporting logs, as well as the vibration generated by chainsaw operation, contributes to increased risk. A RULA assessment aids in visualizing the ergonomic stressors workers are exposed to and enables a comprehensive understanding of the risks present in the task. RULA involves assessing different aspects of upper body posture and force exertion. It uses a scoring system for various postural factors like neck, trunk, arms, and wrists. The scores are then used to determine risk levels and potential improvements. The application of the RULA assessment is as follows:
3
A. Arm and Wrist Analysis
Step 1: Locate Upper Arm Position:
Step 1a: Adjust…
If shoulder is raised: +1
If upper arm is abducted: +1
If arm is supported or person is leaning: -1
The score for the upper arm position of the worker in this scenario is 1 because the shoulder is raised, the upper arm is abducted and the person is leaning.
Step 2: Locate Lower Arm Position:
Step 2a: Adjust…
If either arm is working across midline or out to side of body: Add +1
The score for the lower arm position of the worker in this scenario is 1 because either arm is working across the midline or out to the side of the body.
Step 3: Locate Wrist Position:
Step 3a: Adjust…
If wrist is bent from midline: Add +1
The score for the wrist position of the worker in the scenario is 1 because the wrist is bent from midline.
Step 4: Wrist Twist:
If wrist is twisted in mid-range: +1
If wrist is at or near end of range: +2
The score for the wrist twist position of the worker in the scenario is 1 because the wrist is twisted in mid-range.
Step 5: Look-up Posture Score in Table A, which was 5.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
4
Step 6: Add Muscle Use Score
If posture mainly static (i.e. held>10 minutes),
Or if action repeated occurs 4X per minute: +1
The muscle use score for the worker in the scenario is 1 because the action is repeated 4x per minute.
Step 7: Add Force/Load Score
If load < .4.4 lbs. (intermittent): +0
If load 4.4 to 22 lbs. (intermittent): +1
If load 4.4 to 22 lbs. (static or repeated): +2
If more than 22 lbs. or repeated or shocks: +3
The force/load score is 3 because the load is more than 22 lbs.
Step 8: Find Row in Table C
Add values from steps 5-7 to obtain. The worker in the video has a score of 4.
B. Neck, Trunk and Leg Analysis
Step 9: Locate Neck Position:
Step 9a: Adjust…
If neck is twisted: +1
If neck is side bending: +1
The neck position of the worker in the video is 2 because it is twisted and side bending.
Step 10: Locate Trunk Position:
Step 10a: Adjust…
If trunk is twisted: +1
If trunk is side bending: +1
The trunk position of the worker in the video is 2 because the trunk is twisted and side bending.
5
Step 11: Legs:
If legs and feet are supported: +1
If not: +2
The worker in the video has a score of 1 for legs because his legs and feet are supported.
Step 12: Look-up Posture Score in Table B: the posture score is 4.
Step 13: Add Muscle Use Score
If posture mainly static (i.e. held>10 minutes),
Or if action repeated occurs 4X per minute: +1
The muscle use score of the worker in the video is 1 because the action repeated occurs 4x per minute.
Step 14: Add Force/Load Score
If load < .4.4 lbs. (intermittent): +0
If load 4.4 to 22 lbs. (intermittent): +1
If load 4.4 to 22 lbs. (static or repeated): +2
If more than 22 lbs. or repeated or shocks: +3
The force/load score is 3 because the logs are more than 22 lbs or repeated or shocks.
Step 15: Find Column in Table C, the final RULA score is 4.
Scoring: (final score from Table C) 3-4 = further investigation, change may be needed
3. Quantification of MSD Injury Potential
Although the precise weight of the logs and total task time are not provided, we can make reasonable assumptions. Assuming that the logs are of substantial weight and that the task is performed repeatedly over a significant period, the MSD injury potential is noteworthy. The lack of proper lifting techniques, combined with the awkward postures and repetitive motions, amplifies the risk of
6
developing musculoskeletal disorders over time. While specific quantification may be challenging due to missing data, it's evident that the injury potential is substantial, warranting immediate attention to mitigate the risks.
4. Potential for MSD Injuries
The identified risk factors significantly increase the potential for various musculoskeletal injuries among workers. Awkward postures during log lifting and chainsaw operation can lead to strains in the back, shoulders, and neck. Repetitive motions involved in lifting and transporting logs may result in overuse injuries such as tendonitis. The exertion of force while manipulating logs can lead to muscle fatigue and potential sprains.
Considering the cumulative effect of these factors, workers are at risk of developing chronic musculoskeletal disorders such as herniated discs, carpal tunnel syndrome, and rotator cuff injuries. Early intervention is crucial to prevent these injuries from progressing and impacting workers' well-being.
5. Recommendations for Risk Control
To effectively control the identified MSD risk factors, a multi-faceted approach is recommended, involving engineering controls, administrative controls, and personal protective equipment (PPE):
Engineering Control: The implementation of mechanical lifting aids, such as cranes or hydraulic lifts, can significantly reduce the need for manual lifting of logs. This minimizes the strain on workers' bodies and promotes safer lifting techniques. Additionally, modifying the design of chainsaws to reduce vibration transmission can mitigate the impact of vibration-related risks.
Administrative Control: Implement a job rotation system that alternates between log cutting, lifting, and transportation tasks. This reduces the duration of repetitive motions for each worker and provides them with variety in their activities. Frequent breaks should be scheduled to allow workers to rest and recover from physically demanding tasks.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
7
Personal Protective Equipment (PPE): Provide workers with ergonomic gloves that offer vibration
dampening to mitigate the effects of chainsaw-induced vibration. Additionally, back support belts can be provided to encourage proper posture and reduce the risk of back strains during lifting.
8
Appendix
1.
Washington Industrial Safety and Health Act (WISHA) Lifting Equation:
- Use: Evaluate lifting tasks.
- Calculates: Recommended Weight Limit (RWL).
- Purpose: Determine maximum safe weight to lift.
This equation helps assess the risk of lifting tasks. The formula is as follows:
RWL = LC × HM × VM × DM × AM × FM × CM
Where:
- RWL: Recommended Weight Limit
- LC: Lifting Constant (23 kg for two-handed lifting)
- HM: Horizontal Multiplier
- VM: Vertical Multiplier
- DM: Distance Multiplier
- AM: Asymmetric Multiplier
- FM: Frequency Multiplier
- CM: Coupling Multiplier
2. NIOSH Lifting Equation:
- Use: Assess lifting tasks.
- Calculates: Lifting Index (LI).
- Purpose: Identify risk level for lifting task.
This equation is used to evaluate lifting tasks. The formula is:
LI = Load Constant × HM × VM × DM × CM
Where:
- LI: Lifting Index
9
- Load Constant: 51 lbs (for males) or 37 lbs (for females)
- HM: Horizontal Multiplier
- VM: Vertical Multiplier
- DM: Distance Multiplier
- CM: Coupling Multiplier
3. Rapid Upper Limb Assessment (RULA) Tool:
- Use: Evaluate upper body posture.
- Scoring: Assess neck, trunk, arm, wrist postures.
- Purpose: Identify upper body ergonomic risks.
RULA involves assessing different aspects of upper body posture and force exertion. It uses a scoring system for various postural factors like neck, trunk, arms, and wrists. The scores are then used to determine risk levels and potential improvements.
4. Rapid Entire Body Assessment (REBA) Tool:
- Use: Evaluate entire body posture.
- Scoring: Assess posture, load handling, force.
- Purpose: Identify whole-body ergonomic risks.
REBA assesses the risk of musculoskeletal disorders associated with whole-body postures. It assigns scores to different body parts and factors like load handling, posture, and force. The scores are combined
to give an overall risk level.
5. Snook Tables (Pushing/Pulling):
- Use: Evaluate pushing/pulling tasks.
- Factors: Task height, frequency, weight.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
10
The Snook Tables help assess the risk of pushing and pulling tasks. They consider factors like task height, frequency, and weight being pushed or pulled. The tables provide guidelines to determine risk levels based on these factors.