It is usual to link respiratory and skin health issues to hairdressing job. The most current papers from throughout the world reported on biomechanics as well. Shoulder, lower back, and upper back joints were the most impacted. Several authors conducted ergonomic risk assessments through standardized protocols, like REBA, founding high-risk levels. Other authors measured shoulder and wrist movement with IMU or inclinometer founding a high biomechanical risk. Only one study used electromyography (sEMG) to compare the activity of male and female hairdressers founding those women had considerably higher sEMG activity. This study only measured the muscle work from upper limb flexors and extensors. To our knowledge, no research has investigated the whole upper body kinematics and sEMG from the upper arm, shoulder, and trunk using instrumentally based tools for hairdressers’ risk assessment. The aim of our study is a biomechanical risk assessment of the subtask of hair drying in two different ways (horizontally – HOR and upwardly - UP). We acquired four expert workers using an optoelectronic system and sEMG. sEMG results showed that the left side of the body was generally more involved than the right one in both the assessed tasks. Latissimus Dorsi, Trapezius Superior, Deltoideus Anterior, and Flexor Carpi Ulnaris were severely affected by this. In the UP task, the shoulders (Trapezius Superior and Deltoideus Anterior) had high mean percentage of Maximum Voluntary Contraction (%MVC) values. According to our sEMG results, holding a phone that weighs almost 1 kg in a static position is less straining on the upper limb and shoulder than constantly moving the left hand while holding a small comb. Kinematic data seems to support this. The left side showed the highest Range of Motion (RoM) values than the right for shoulder abd-adduction and elevation on the UP task and shoulder horizontal abduction, elbow flex-extension, and wrist prono-supination on both tasks. The shoulder flex-extension showed comparable high RoM values in both tasks.Our findings also show a high standard deviation for RoMs, indicating a high heterogeneity in performing the same task. Our research found that hair-drying is a demanding task for hairdressers. We recommend using wearable technologies to have a more reliable work situation instead of standardized protocols for risk assessment.

Many scientific papers report that curbside waste collection is a work with high biomechanical load. Our previous papers highlighted the biomechanical risk in this activity and we identified these main risk factors: bad design of equipment, landscape and the number of households covered. The high variability of this task makes it hard to apply standardized protocols for biomechanical risk assessment. For this new experience, we used pulse rate monitors to assess cardiac effort during a full day of pick-up in two different days for two operators gathering bio-waste and glass. The first worker pick-up the waste in the same area on both days. The second worker pick-up waste on zones with different morphology and different urban density. We also recorded GPS data from the second worker. We analyzed heart rate calculating Relative Cardiac Cost (RCC) and heart rate distribution. The first worker performed the task in the municipal urban area and reported a RCC of 43 and 45%. Both values correspond to a heavy work level on the Chamoux scale. The second worker reported RCC values of 36% when collecting in the municipal urban area (quite-heavy work level) and 23% in the non-urban hilly area (moderate work level). The heart rate of the second worker exceeded 140 bpm 7.7% of the time and ranged from 110 to 130 bpm for 72.6% of the time in the municipal area. In the non-urban area, 140 bpm heart rate was never reached and heart rate values were between 110 and 130 bpm for 16.6% of the time. No differences resulted in the first worker due to the type of waste collected. For the second worker, we found a relevant difference in heart rate distribution, probably not related to the type of waste but rather to the number of households and the morphology of the landscape. GPS data seem to support these findings. In the municipal area, the worker moved 17.6 km at a mean speed of 4.8 km/h. In the non-urban area, the worker moved 40.84 Km at a mean velocity of 7.8 Km/h. The higher speed and more than twice the distance covered highlight that the worker spent much more time driving the truck in the non-urban zone than in the municipal one resulting in a reduced biomechanical workload. In conclusion, combined data from heart rate monitor and GPS allowed us to highlight the different workloads between the two zones, municipal and non-urban. We suggest alternating the workers between them to reduce biomechanical risk.

The biomechanical risk of cashiers in the retail sector has been extensively studied in literature. Despite high back pain prevalence in this sector manual material handling (MMH), instead, seems almost ignored. The aim of our study is MMH risk assessment in a fruit and vegetable department of a supermarket. This task wasn't still investigated, to date, together with standardized protocols and instru-mental-based tools. The sizes of the shelf allowed the use of the NIOSH protocol for the low level, whereas middle and high did not allow its use due to horizontal distance that exceeded the 63 cm set by the protocol. To integrate the NIOSH pro-tocol was used surface electromyography (sEMG). The recommended weight limit (RWL) in our case, according through NIOSH liftinq equation, was 17 Kg. The maximum handled weight from the workers was 14 Kg. The maximum mean peak value while lifting 14 Kg at a low level was 40.1% of Maximum Voluntary Contraction (MVC) in the left Erector Spinae. We assumed this sEMG value to be a safety value and used as a limit for lifts at the middle and high shelf levels because the maximum handled weight of 14 Kg was lower than the 17 Kg limit calculated through the NIOSH equation for the low level. This sEMG limit was exceeded, in the middle, while lifting 14 Kg (47.8% MVC), and in the high level lifting 10 Kg (44.7% MVC), 12 Kg (50.3% MVC), and 14 Kg (57.7% MVC). Our findings show that, for the analyzed shelf and for the male working popula-tion of that supermarket, we could accept as reasonably safe handling boxes up to 14 Kg for the low level, up to 12 Kg in the middle, and up to 8 Kg in high. This study shows that the integration of different assessment tools, such sEMG and NIOSH protocol, could help to a better estimation of biomechanical risk assess-ment. The study, moreover, provided practical guidelines for the health and safety service concerning the recommended load handled on each shelf level to minimize the risk of MMH in the fruit and vegetable department.

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