In-depth survey report: ergonomic interventions for the soft drink beverage delivery industry at Pepsi-Cola Company, Dayton, Ohio, report no. ECTB-181-12a.
The objectives of this National Institute for Occupational Safety and Health (NIOSH) study were to investigate, identify, and remove risk factors which may cause musculoskeletal disease and injury in the soft drink beverage delivery industry. A field study of nine soft-drink beverage deliverymen (ages 34 to 58) was conducted over a four month period in 1993. Ergonomic evaluations of the truck bays showed that they exceeded the normal reach limit of workers. Extended reaches for heavy beverage cases can significantly increase the risk of musculoskeletal injuries. During the field survey several ergonomic interventions to reduce and prevent musculoskeletal injuries were implemented, which included 1) engineering controls for easier access to beverage products, such as A) pullout steps, B) external handles, and C) multi-level shelving units, 2) two-wheel handtrucks with counter-balancing devices. 3) substitution of plastic beverage containers for glass containers to reduce weight, and 4) improved beverage carton design for better manual coupling during beverage product handling. Changes in work risk factors were documented through videotaping biomechanical modeling of manual material handling, continuous heart rate monitoring, and analysis of psychophysical discomfort assessment surveys. Measurement differences were compared before, during, and after ergonomic interventions were made to the beverage delivery trucks and in the delivery process. Initially, discomfort reporting increased while new work routines and use of ergonomic interventions were developed for beverage delivery tasks. The lower back, knees, right elbow, and right shoulder were the most frequently reported locations of discomfort. However, as the beverage deliverymen developed experience with the ergonomic controls, the frequency and magnitude of body discomfort reporting decreased. The benefits of the ergonomic interventions were in proportion to the amount of time such controls were used. Reductions in biomechanical stressors for the back and shoulders were observed when pullout steps, external handles, and multilevel shelving were used. Heart rate decreased for six of nine deliverymen from the beginning versus the end of the survey, despite an increase in the product volume handled. The ergonomic interventions, in combination with improved work practices, reduced fatigue, the amount of beverage handled per day, and awkward postures during beverage handling. Favorable reports from the deliverymen in the study about the effectiveness of these controls helped convince management that all new trucks should have ergonomic changes made. Other beverage delivery companies could also benefit from the lessons learned in this study with the resulting recommendations since the risk of a musculoskeletal injury during beverage delivery was found to be 100 percent among those deliverymen surveyed. The NIOSH lifting criteria showed that most of the beverage lifting tasks exceeded the Recommended Weight Limit (RWL). Heart rate results and indirect measurements of metabolism showed that the job of beverage deliverymen is physically demanding, especially during peak delivery periods. Statistically speaking, the probability of such musculoskeletal injuries, in terms of days lost, is twice as high for the beverage deliverymen as for those in general manufacturing jobs. Engineering controls are recommended, along with rest breaks during peak delivery periods to prevent fatigue and reduce injuries.