## 3 Results  
### Productivity Analysis  
The productivity analysis was conducted over 2 h work periods, with measurements taken at 30 min intervals (0-30, 30-60, 60-90, and 90-120 min). The results represent the average values of 20 participants, each performing tasks under both low-intensity and high-intensity conditions. This averaging of multiple participants' performance data provides more reliable and statistically significant results while accounting for individual variations in work capacity. For the sack carrying task (CT), under low-intensity conditions (level surface), the exoskeleton group maintained higher productivity throughout the work period, starting at 48.7 sacks per 30 min and declining to 42.5 sacks in the final interval. The non-exoskeleton group showed a steeper decline from 40.3 to 32.8 sacks. Under high-intensity conditions (inclined surface), the difference was more pronounced, with the exoskeleton group completing 45.2 to 38.6 sacks across intervals, compared to 35.8 to 28.1 sacks without assistance. These decimal values reflect the mean performance across all participants, providing a more precise measure of the overall productivity impact. In the masonry task (MT), low-intensity conditions (waist-level work) showed consistent benefits from exoskeleton use, with completion rates of 7.8 to 6.9 layers versus 6.5 to 5.1 layers without. High-intensity conditions (ground-level work) demonstrated even greater advantages, with rates of 6.9 to 5.9 layers with the exoskeleton compared to 5.2 to 3.7 layers without indicating substantial fatigue mitigation benefits. The scaffolding installation task (ST) showed similar patterns. Under low-intensity conditions (clamp installation), average productivity with the exoskeleton ranged from 23.6 to 21.2 components compared to 19.5 to 15.6 without. High-intensity conditions (frame installation) showed rates of 17.8 to 15.3 components with the exoskeleton versus 14.5 to 10.7 without. Table 1 and Figure 5 presents detailed measurements across all conditions and time intervals. To determine the statistical significance of productivity differences between exoskeleton and non-exoskeleton conditions, paired \(t\)-tests were performed for each task type and intensity level. The analysis examined both the overall average productivity and the time-segmented productivity values across the 2 h work period. The results of these statistical analyses are presented in Table 2.  
The paired \(t\)-test results revealed highly significant differences (\(p<0.001\)) between exoskeleton and non-exoskeleton conditions across all task types and intensity levels. The highest \(t\)-statistic values were observed in high-intensity conditions, particularly for the sack carrying task (\(t=19.74\)) and scaffolding installation task (\(t=18.46\)), indicating that the exoskeleton's impact was most substantial in these scenarios. The calculated effect sizes  
For the time-segmented analysis, the productivity advantage of exoskeleton use grew more pronounced as the work period progressed. During the first 30 min, the average productivity improvement across all tasks was 20.8% (\(t\) = 11.75, \(p\) < 0.001) while, in the final 30-min interval, the improvement increased to 29.6% (\(t\) = 17.42, \(p\) < 0.001). This pattern suggests that the exoskeleton not only enhanced immediate productivity but also provided increasing benefits through fatigue reduction during extended work periods. Repeated measures ANOVA revealed significant main effects for exoskeleton use (F = 46.3, \(p\) < 0.001), task intensity (F = 38.5, \(p\) < 0.001), and time intervals (F = 30.2, \(p\) < 0.001). This statistical method was chosen for its ability to analyze data where the same participants were measured across multiple conditions while controlling individual variability.