Effects of carrying handles, postures, materials and distances on carrying capability

Team manual handling: a systematic review for identifying research gaps

Objectives. Team manual handling, a process still common in many jobs, can affect the safety and health of employees. A systematic review of the literature was conducted to identify the research gaps in this area for future studies. Methods. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology was followed. Related papers were searched on PubMed, Web of Science, ProQuest and Scopus electronic databases until September 2020. Results. A total of 300 papers were identified, of which 28 were selected for final review based on the respective criteria. The findings of these studies were classified and evaluated based on biomechanical, physiological and psychophysical approaches. No study was found for the epidemiological approach. Only three papers mentioned the body physiological responses in team manual handling. The focus of the related studies found in this field was team lifting. No study was found on team pulling and pushing. Most studies were performed in a laboratory setting using young students who had no experience of team manual handling. Conclusion. The results of this study emphasize the need for further research, especially using the epidemiological and physiological approaches in different tasks of team manual handling in real work environments using experienced workers.

Development and Investigation of a Wearable Aid for a Load Carriage Task

Anterior load carriage tasks are common and can lead to musculoskeletal disorders such as lower back pain. The objectives of this study were to develop a wearable carriage aid and examine its effectiveness on physical demands while considering the potential moderating influence of the carried load. The study consisted of two within-subject factors: device and load. For the former, two levels were tested: with and without the device worn. For the latter, two loads were examined: 15 and 30% of each individual’s body mass. Sixteen participants walked on a treadmill for five minutes at a constant speed for each condition. Physical demands were quantified using objective (EMG-based) and subjective (discomfort) measures. Wearing the device reduced static and median anterior deltoid, trapezius, and biceps brachii muscle activations. Increasing the carried load increased most physical demand measures. Two significant Device×Load interactions were observed; for the anterior deltoid and trapezius median activation measures, the influence of increasing load was lower when the device was worn. While slightly increasing perceived discomfort in the lower back, wearing the device reduced shoulder, neck, and hand/wrist discomfort. While the study demonstrated a potential for the device, future work is required under more realistic and diverse testing conditions.