Application of wearable technologies for the assessment of an ergonomic intervention in hairdressers: preliminary results

Abstract

Several authors conducted ergonomic risk assessments through standardized protocols, like REBA, founding high-risk levels of hairdressing jobs. Others measured shoulder and wrist movement with IMU or inclinometer and found a high biomechanical risk. One study used electromyography (sEMG) to investigate flexors and extensors of upper limb to compare the activity of male and female hairdressers founding those women had considerably higher sEMG activity. In our previous study, we investigated the kinematic of the neck, trunk, and upper limb and sEMG bilaterally from Latissimuss Dorsi, Erector Spinae, Trapezius Superior, Deltoideus Anterior, Extensor Carpi Ulnaris, Flexor Carpi Ulnaris in hair drying in two different ways (horizontally – HOR and upwardly - UP). We found a high standard deviation for RoMs, indicating a high heterogeneity in performing the same task. Our sEMG results showed that, in both investigated tasks, the left side of the body was generally more involved than the right one. The right side, the one holding the phone, showed less %MVC mean values than the right side, the one holding the comb. Our sEMG results suggest that handling a 1 kg phone in a static position is less demanding for upper limbs and shoulders than using a light comb in continuous motion. In another paper, we investigated, through REBA and 3DSSPP, the static posture of workers after a corrective action consisting of a hairdryer holder. We found that the holder contributes to changing the posture in either positively and negatively. The positive effects seemed more than the negative ones. In this new paper, we investigated the effect of the hair dryer holder in dynamic situations founding that there are no significative improvements in the biomechanics of the workers. Moreover, the holder seemed to increase several investigated RoMs. The workers also complained of decreased flexibility of the wrist. Our results suggest that the holder system seems to have more negative than positive effects. To reduce the biomechanical overload in hairdryer, we suggest to improve several aspects, the training, the equipment (lighter hairdryer and adjustable seats), and increasing the breaks.

Keywords: Ergonomic, Hairdresser, Drying, Electromyography, Kinematic

DOI: 10.54941/ahfe1005050