Musculoskeletal models may enhance our understanding of the dynamic loading of the joints during manual material handling. This study used state-of-the-art musculoskeletal models to determine the effects of load mass, asymmetry angle, horizontal location and deposit height on the dynamic loading of the knees, shoulders and lumbar spine during lifting. Recommended weight limits and lifting indices were also calculated using the NIOSH lifting equation. Based on 1832 lifts from 22 subjects, we found that load mass had the most substantial effect on L5-S1 compression. Increments in asymmetry led to large increases in mediolateral shear, while load mass and asymmetry had significant effects on anteroposterior shear. Increased deposit height led to higher shoulder forces, while the horizontal location mostly affected the forces in the knees and shoulders. These results generally support the findings of previous research, but notable differences in the trends and magnitudes of the estimated forces were observed.

Manual material handling is common in supermarkets and may be a contributing factor to the high prevalence of work-related musculoskeletal disorders, particularly to the lower back. This cross-sectional study applied state-of-the-art musculoskeletal models driven by kinematic data obtained in two supermarkets to estimate joint reaction forces in the knees, shoulders and lumbar spine under dynamic lifting conditions. Based on 1479 lifts from 15 workers, 8 tasks for which the compression or shear forces in the L5-S1 joint exceeded well-known biomechanical tolerance limits were identified. High shoulder forces were associated with lifting relatively heavy merchandise to high shelves, while the weight of the handled merchandise was the main predictor of high knee forces. The study addressed well-known limitations associated with traditional lifting analysis tools and was the first to present a detailed analysis of the biomechanical loads during manual material handling tasks in the supermarket sector based on field measurements.

Work-related musculoskeletal disorders are highly prevalent in the supermarket sector with manual material handling being one of the most commonly identified occupational risk factors. This cross-sectional study applied inertial motion capture and electromyography (EMG) to measure full-body kinematics and muscle activity of trapezius descendens and erector spinae longissimus during 50 manual material handling tasks performed by 17 workers in two supermarkets. The handling of bread and cucumbers to high shelf heights showed the highest trapezius muscle activity (from 47% to 59% peak normalized EMG), while the handling of bananas as well as lifting milk, bread and cucumbers from low to high positions showed the highest erector spinae activity (from 59% to 71%). Twenty-two tasks involved flexing the shoulders and trunk more than 90° and 50°, respectively. Based on these results, several manual handling practices in supermarkets should be reconsidered to reduce the physical work demands.

Designspecialists have acknowledged the need for more accurate measurements of human anthropometry through the use of 3D data, especially for the design of head and facial equipment. However, 3D anthropometric surveys of the human head are sparse in the literature and practically non-existent for Australia. Research published to date has not proposed concrete methods that can accurately address the hair thickness responsible for inaccurate representation of the head's shape. This study used a state-of-the-art handheld white light scanner to digitize 3D anthropometric data of 222 participants in the Melbourne Metropolitan Area. The participants volunteered for the study consisted of 46 females and 176 males (age: 34.6 ± 12.5). The participants’ head scans were aligned to a standard axis system, whereby a Hair Thickness Offset (HTO) method was introduced to more accurately describe the true shape of the head. It is envisaged that the database constructed through this research can be used as a reference for the design and testing of helmets in Australia

High physical work demands increase the risk of musculoskeletal disorders and sickness absence. Supermarket work involves a high amount of manual material handling. Identifying specific ergonomic risk factors is an important part of occupational health and safety efforts in the supermarket sector. In this cross-sectional field study among 64 supermarket workers, we used electromyography during the workday to determine the influence of lifting height and load mass on muscular workload of the low-back and neck/shoulder muscles during un-restricted manual material handling (grocery stocking). We found a significant effect of load mass, i.e., higher loads associated with higher muscular workload in the low-back and neck/shoulder muscles. We demonstrated a significant interaction between start and end position, i.e., lifts performed from ‘Low’ start positions to ‘High’ end positions demonstrated the highest low-back muscular workload, whereas ‘High’ positions were associated with increased neck/shoulder workload. In conclusion, lifting higher loads and lifting goods from low to high positions (low-back) and at high positions (neck/shoulder) are associated with higher muscular workload. These results can be used to guide highly warranted preventive initiatives to reduce the physical workload during supermarket work.