Ergonomic Assessment of Assembly Line Worker Using REBA and RULA Methods Essay

Problem Background

One of the responsibilities of the company’s safety department is to ensure the consistency and integrity of safe workplace conditions for all employees engaged in their professional duties while at work. In this regard, this paper is intended to outline the essence of one of the employees’ complaints regarding the working conditions that cause them pain due to the repetitive movements required when sorting boxes on the assembly line. This paper aims to explain the problem and investigate the impact of workplace conditions on the health and well-being of employees. Furthermore, one intends to conduct the Rapid Entire Body Assessment (REBA) and the Rapid Upper Limb Assessment (RULA) calculations, compile recommendations, and submit a request for changes to ensure safe working conditions. The recommendations and assessments will be based on the Occupational Safety and Health Administration (OSHA) General Duty Clause and standards.

Case Overview and Risks for the Employee

An employee working at an assembly line at a box sorting station has complained about the inappropriate working conditions. Their concern is with the issues of hip, back, neck, and shoulder pain caused by twisting, lifting, and bending when sorting boxes in five different bins located to the left, right, in front, above, and across the conveyor. Repetitive movements in this direction cause pain to the employee, which is why they are requesting changes to eliminate the causes of pain and improve work conditions. In this regard, it is considered relevant to investigate the case, revise the ergonomics of the assembly line process in relation to the employee’s responsibilities, and make adjustments as much as possible to minimize the risks of injury and pain (Stack et al., 2016). Therefore, it is essential to identify the general potential risks faced by employees due to the current working conditions.

In particular, the character of the worker’s responsibilities is bound to repetitive actions throughout the shift. According to Stack et al. (2016), ergonomics implies “fitting the task and work environment to the human,” which means designing “tasks and workplaces within the capability of the human” (p. 455). Although the task of the employee filing the complaint is adjusted to human capabilities, it is insufficiently adjusted to comfort and injury elimination, which is essential, especially when performing actions with limited movement variety and scale. Indeed, “common causes of injury are as follows: repetitive gripping/twisting, repetitive reaching, repetitive moving, and static postures” (Stack et al., 2016, p. 456). The complaint detects all these causes and should be verified, given OSHA standards and practice implications.

OSHA Considerations

An employer must ensure that the workers are provided with workplace conditions that comply with the requirements of OSHA. This organization aims to regulate employee-employer relations and provide sufficient guidelines for implementing standardized workplace interaction (OSHA, 2023). In particular, the organization is expected to ensure that employees have the right to a safe and healthful workplace, as regulated by the General Duty Clause of the Occupational Safety and Health Act (OSHA, 2023). According to the General Duty, “Employers have the responsibility to provide a safe and healthful workplace that is free from serious recognized hazards” (OSHA, 2023, p. 7).

Moreover, specific standards developed by OSHA, including Standard 501(a), require employers to adjust working conditions to meet the ergonomic requirements of humans, thereby minimizing workplace hazards. Moreover, the standardization of workplace conditions enables a precise assessment of risks and exposure to potential hazards, justifying the necessity of change. In this regard, REBA and RULA calculations are relevant to the case, as they help identify the employee’s workplace threats and develop appropriate recommendations.

Potential Injuries Based on RULA and REBA

When calculating potential injuries the employee faces when completing their job task at the assembly line, one should refer to RULA and REBA assessments. In particular, RULA allows for the analysis of upper limb scores to identify the level of hazard and injury exposure (Stack et al., 2016). It involves fifteen steps to score each part of the upper body as it is positioned during the work. In this case, the analysis is performed step-by-step, with the results of each step’s calculations presented below.

• Step 1: The upper arm position is estimated at +3 due to the angle of 45-90 degrees. It is adjusted by +1 because the employee lifts their shoulders when placing the boxes into a bin above their head; thus, the score is +4.
• Step 2: The lower arm position is estimated at +2 due to the movement in downward and upward directions; it is adjusted by +1 due to the midline crossing movement; thus, the score is +3.
• Step 3: Wrist posture remains stable; the score is +1.
• Step 4: The wrist twist is characterized by a score of +1 because it is twisted along the midline.
• Step 5: The posture score based on previous steps is 4.
• Step 6: Muscle use score is 4+1 due to the repeated actions, which results in a score of 5.
• Step 7: Given the load varying from 4.4 to 22 lb, the score is +1, which gives the result 6.
• Step 8: According to Table C in Stack et al. (2016), the wrist and arm score is 6.
• Step 9: The neck position is +3 due to the head tilt angle; it is adjusted by +1 due to the neck twisting, resulting in a +4 score.
• Step 10: The trunk position is +4 and adjusted by +1 due to the twisting, which results in +5.
• Step 11: Legs are not supported, so the score for legs is +2.
• Step 12: The leg, torso, and neck score is 7, based on the scores of the three previous steps.
• Step 13: Since the action is repeated, a +1 score is added to 7, which gives 8.
• Step 14: Since the load is 4.4 to 22 lb, the score is +2, giving 10.
• Step 15: The final RULA score is 7, which implies that “the person is working in the worst posture with an immediate risk of injury from their work posture, and the reasons for this need to be investigated and changed immediately to prevent an injury“ (Stack et al., 2016, p. 346). Thus, the employee’s claim is valid, and their working conditions should be improved.

Another assessment is REBA, which allows for the whole body assessment.

• Step 1: Neck position +2 and adjusted by +1, resulting in +3.
• Step 2: The trunk starts at +4 and is increased by +1, giving a final position of +5.
• Step 3: Leg position is +1 since both legs are supported and adjusted by +1 due to the knee bend, resulting in +2 for the leg position.
• Step 4: The posture score is 8.
• Step 5: The posture score of 8 is adjusted by +1 due to the load, resulting in 9.
• Step 6: Finding row in Table C (Stack et al., 2016).
• Step 7: The upper arm position is +3 and adjusted by +1 due to the shoulder rise, which results in +4.
• Step 8: Lower arm position is +2.
• Step 9: Wrist position is +2.
• Step 10: cumulative posture score based on the previous three steps is 6.
• Step 11: The coupling score is +1.
• Step 12: The final score is 11.
• Step 13: The final score should be adjusted by +1 due to repeated actions. The ultimate score is 12, which is action level 4 with a high level of risk, and the action is necessary now.

Recommendations for Correcting the Issue

Given the high level of risks and urgency of action as implied by the assessment results, the working conditions for the employee should be adjusted immediately to avoid injury. In this regard, several recommendations might be applicable, among which substitution and engineering controls should be considered. In particular, Stack et al. (2016) state that a substitution is an approach that requires altering the exposure to the threatening job by adjusting the working conditions. In this regard, the sorting bins might be located near the worker to eliminate the need to bend and reach above the head.

Another possibility to address the issue is by adhering to engineering controls, which might allow for changing the sorting process by subdividing boxes into two categories first and then sorting them into two or three groups, which would ease the posture load for the workers. Furthermore, according to OSHA’s (2OSHA’secommendations, the Safety Director might refer to knowledgeable workers to elicit their vision of improved conditions in the workplace. Thus, the implementation of these recommendations based on the calculations that were conducted might improve the safety of the workplace.

References

Occupational Safety and Health Administration. (2016). Recommended practices for safety and health programs. Web.

Occupational Safety and Health Administration. (2023). Workers’ rights. Web.

Stack, T., Ostrom, L. T., & Wilhelmsen, C. A. (2016). Occupational ergonomics: A practical approach. Wiley Professional Development (P&T).