# Ergonomic Assessment of Physical Load in Slovak Industry Using Wearable Technologies
## 3 Results  
The result of the ergonomic evaluation is a comparison of the measured values with limit values given by the legislation or individually adjustable criteria, classification of works into categories, recommendations for the implementation of measures to reduce physical activity (organizational, ergonomic, technical, etc.). Ergonomic assessments are complementary in accordance with the Council Directives [33; 34; 35; 36; 37; 38]. The results in Table 3 represent data for one evaluated worker proceeded by the Captiv system. It describes the ratio of time duration and how long the particular body segment spent in a certain threshold area. The difference method was chosen for comparing the results from both types of experiments, STAND and EXO, to judge quantitative change to find out the level of difference between them; formula 1 was used:  
\[\Delta E_{A}=E_{W_{A}}-E_{N_{A}} \tag{1}\]where \(\Delta E_{A}\) is the difference value to compare both types of experiments, \(E_{W_{A}}\) is the value representing the ratio between durations of times when the observable occurred in one of three zones (green + orange + red = 100%) during experiment EXO (with exoskeleton), and \(E_{N_{A}}\) is the value representing the ratio between durations of time when the observable occurred in one of three zones (green + orange + red = 100%) during experiment STAND (without exoskeleton). A change of the ratio \(\Delta E_{A}\) gives difference values, decrease (\(-\)) or increase (\(+\)). An increase in the green zone means positive change; an increase in the orange zone means positive change only if the red was decreased, and negative change if the green was decreased. An increase in the red zone is always negative. The obtained results correspond to the periods when the subject's exposure to the risk was greater than the acceptable threshold. Figure 3 shows the level of activity in the colors (green: appropriate, orange: indicates a change in activity, red: inappropriate). The results in Figure 3a show STAND experiments, and Figure 3b shows the EXO experiments. Comparing the results in Table 3 in the neck joint, there was a visible improvement in neck flexion/extension of 34.1%, the angle exceeding 30\({}^{\circ}\) in neck flexion was reduced to the level between 15\({}^{\circ}\) to 30\({}^{\circ}\), in neck extension from above \(-\)20\({}^{\circ}\) to the range of \(-\)10\({}^{\circ}\) to \(-\)20\({}^{\circ}\). However, neck rotation was with or without exoskeleton still in the red area over 10% from the total time and even raised in 2% together with orange raised in \(-\)10%. Similarly, the risk was raised in the EXO experiments for both shoulders, moving about 10% from the green zone to orange and red. Therefore, we need to improve the height adjustment of the workplace table because, during the sitting position, the situation was worse for shoulder manipulation. The measured data (Figure 3) were displayed via 3D Captiv avatar, in green/orange/red colors based on customizable threshold values for the reference angles. Green indicates suitable parameters, orange indicates a change in activity, and red indicates inappropriate activity with an immediate need for correction. Results shown in Figure 4 reflect detailed Neck flexion/extension time duration in individual postures in experiments with the exoskeleton. When we look at the hip, the left side was pulled more than the right side, and the left hip rotation in the experiment without the exoskeleton was in the orange color region, representing 77.1% of the total