## 4 Discussions
The analysis of power and mechanical energy indicated that for the coefficient of generated power and loss power ratio \(\lambda\), the decrease of 18% was observed. The skewness \(\mu\) of the measured coefficient distribution \(\lambda\) is also of importance here. It was right-sided for ramp climbing with the activated and deactivated anti-rollback system. Therefore, for the majority of the performed tests, the coefficient values \(\lambda\) were higher than the average value. Whereas, the average coefficient value \(\lambda\) for ramp climbing with the activated anti-rollback system was 0.8 and for ramp climbing with the deactivated anti-rollback system it was 0.97. The differentiation of coefficient \(\lambda\) indicates the significant impact of additional motion resistances resulting from the use of the anti-rollback system. In the event of the total mechanical energy of a single propelling cycle, it was observed that the use of the anti-rollback system did not exert any significant impact. Based on the measured values it was determined that the total mechanical energy o \(E\) decreased on average merely by 3% during ramp climbing with the activated anti-rollback system. Referring to the individual evaluation of kinematic parameters for respective participants, it was determined that for 88% tested participants, the increase in the propelling cycle duration time \(t\) was observed cycle, which on average amounted to 6% as compared to ramp climbing with the deactivated anti-rollback system. This proves the performance of propelling cycles with lower frequency. Probably, such a phenomenon is a consequence of the feeling of safety [42] in users who did not have to worry about wheelchair rolling down in the event of decreasing the frequency of propelling cycles. For 63% participants, the maximum velocity decrease \(v_{max}\) was recorded on average as 12% during ramp climbing with the activated anti-rollback system. For the same number of participants, the decrease was observed in coefficient \(\lambda\), which was 17% during ramp climbing with the anti-rollback system. While analyzing the changes in the value of the total mechanical energy, it was observed that in 50% participants there was the increase of mechanical energy. In the event of the push phase measurement in the propelling cycle, it was observed that in 63% of participants, an increase was observed and in 37%--a decrease was observed in the push phase. Whereas, the difference in the shares of the push phase depending on the activation of the anti-rollback system did not exceed 1%. A main factor affecting the differences among respective participants in the increases or decreases of respective kinematic parameters during ramp climbing with the activated or deactivated anti-rollback system includes physical conditions such as static force during pushing and body performance [46]. In the case of participants with a push force lower than the average (for all subjects), the greatest drops in the kinematic parameters of the wheelchair were found while using the anti-rollback system. In participants with a high physical fitness, the high amplitudes of wheelchair acceleration were observed which resulted directly in the value of mechanical energy. The analysis of muscle activity (MA) demonstrated that during the use of the anti-rollback system when climbing the ramp, the participant's muscle system was exposed to a higher effort as compared to ramp climbing without the use of the anti-rollback system. An exception from the above observation was determined only in two cases. During the _MA_ measurement of deltoid muscle posteriori for Participant 2 with the recorded 0.62% decrease during the use of the anti-rollback system, and the _MA_ measurement of triceps brachii for Participant 5, with the observed 21.27% decrease during the use of the anti-rollback system. During ramp climbing, the highest _MA_ increase was recorded for Deltoid muscle anterior. The average _MA_ increase value during ramp climbing with the activated anti-rollback system was 18.56%.