## 4 Discussion  
Incline walking and load carriage are external factors that can alter spatiotemporal gait parameters. Both can be related to external stress on the musculoskeletal system, requiring adaptations of posture and movement patterns. Thus, the primary aim of this study was to assess how the incline of the treadmill and the position of the load affected walking while carrying a backpack asymmetrically. The main finding was that both factors, incline and load position, significantly affect spatiotemporal gait parameters, which is consistent with the stated hypothesis. Current findings agree with previous studies on spatiotemporal gait patterns, which have reported that step length increases with increasing incline and cadence decreases  
Figure 3: Plots show statistically significant (\(p<0.05\)) interactions between inclination and load position. Vertical bars denote 0.95 confidence intervals and markers denote means: (**a**) cadence; (**b**) gait cycle; (**c**) swing phase; (**d**) stance phase. uphill as the angle of incline increases. These results are likely linked to the fact that walking on an incline requires greater force exertion across the hip, knee, and ankle, as well as increased ankle movement [30]. [PERSON] et al. investigated level (0%) and uphill (5, 10 and 15%) walking at a speed of 5 km/h without and with a front pack or a backpack (15% of body weight). The main finding of [PERSON] et al. 's study was an interaction between inclination and backpack position for stride length and cadence, which is consistent with our findings [31]. In the current study, changes observed between slope and level walking were similar in all three conditions of load. However, there were some differences between load positions. Previous studies reported that walking speed and cadence decreased significantly with increasing backpack load, while double support time increased. The demand for increased power at the lower limb joints increased with the amount of weight carried in the backpack [32]. Children also walked with a slower cadence with a load brought to school. Backpack carriage with different loads did have a significant effect on force distribution and plantar pressure [33]. Even when the load was light (4 kg), noticeable shifts in body posture and pressure distribution were detected when individuals carried weight asymmetrically using their hands [13]. The findings of [PERSON] et al. suggest that carrying loads of 10% of the body weight or more should be avoided, as these loads cause significant changes in electromyography, kinematics and subjective feelings of discomfort ([PERSON]'s rating scale) [24]. Our findings lead us to a similar conclusion; that 10% of the body weight can significantly affect gait parameters in both positions, in hand and on the shoulder. However, the speed was set at the beginning and was steady during trials, in contrast to previous studies [32; 34]. For this reason, participants had to adapt their gait to maintain the pace. That can explain some differences between the current study and previous ones. Subjects carrying loads by their sides may increase their cadence and decrease their stride length in order to maintain velocity. We found that step length and gait cycle were the shortest and cadence was the greatest when the backpack was carried in hand compared to the shoulder position and no load. There were no statistically significant differences between shoulder position and no load. That implies that the lower position of the load may have affected these parameters. Individuals can increase cadence and simultaneously decrease step length to maintain speed when carrying the load in hand for two reasons. Carrying a backpack in the hand and taking long steps can involve a large swing of the load, which is not so noticeable when the load is on the shoulder. Load swing is a perturbation and can affect balance during walking, and thus a reduction in step length is an adaptation to avoid balance disturbance [35].