# Manual Wheelchair Equipped with a Planetary Gear-Research Methodology and Preliminary Results
## 3 Results and Discussion
### Results of EMG Measurements
The effort of the wheelchair's operator (measured by the \(SA\) value) decreased as the angle of the inclination of the wheelchair decreased and the gear ratio increased. These changes were recorded consistently for each measurement test. The statistical analysis carried out allows for concluding that both the change in the angle of inclination of the wheelchair as well as the change in the gear ratio of its propulsion system, and their combination, influenced the determined values of the area (\(SA\)) under the MVC diagrams. The change in the gear ratio and the increase in the resistance to movement resulting from the angle of inclination affected the position of the wheelchair user in relation to the axis of the rear wheel. The nature of the kinematics of the movement of the upper limbs and muscle electromyography is similar to the results of the research by [PERSON] et al., 2018, which analyzed the impact of the position of the rear wheel axle on a wheelchair's user ([PERSON] et al., 2018). The necessary statistical data are contained in Table 3. For all measurements, very small values (\(p_{val}\)) can be observed, so there is great certainty that the observed changes were significant. Figure 10 shows the average amplitude values of the EMG (\(MVC_{MAX}\)) signal for all propulsion cycles in experiments s2. The necessary statistical data are contained in Table 4. As the analysis of the data provided shows, the changes occurring in the average EMG signal amplitude values were similar to the values of the areas. \begin{table}
\begin{tabular}{c c c c c c c c} \hline  & \(F\) & \(p_{val}\) & \(F\) & \(p_{val}\) & \(F\) & \(p_{val}\) & \(F\) & \(p_{val}\) \\ \hline  & & **s1 A** & & **s1 B** & & **s1 C** & & **s1 D** \\ \hline
**p1-3** & \(166.07\) & \(8.46\times 10^{-41}\) & 206.21 & \(2.69\times 10^{-46}\) & 665.36 & \(2.10\times 10^{-81}\) & 1192.56 & \(3.74\times 10^{-101}\) \\ \hline
**k1-3** & \(39.62\) & \(7.29\times 10^{-15}\) & 96.99 & \(7.02\times 10^{-29}\) & 472.89 & \(2.09\times 10^{-70}\) & 2350.68 & \(4.16\times 10^{-125}\) \\ \hline
**Interaction** & \(18.34\) & \(1.48\times 10^{-12}\) & 15.84 & \(4.74\times 10^{-11}\) & 31.42 & \(1.29\times 10^{-19}\) & 540.83 & \(7.04\times 10^{-96}\) \\ \hline  & & **s2 A** & & **s2 B** & & **s2 C** & & **s2 D** \\ \hline
**p1-3** & \(170.93\) & \(1.64\times 10^{-41}\) & 429.84 & \(1.99\times 10^{-67}\) & 667.01 & \(1.74\times 10^{-81}\) & 201.49 & \(1.09\times 10^{-45}\) \\ \hline
**k1-3** & \(404.84\) & \(1.4\times 10^{-65}\) & 539.42 & \(1.38\times 10^{-74}\) & 830.89 & \(8.42\times 10^{-89}\) & 1673.81 & \(5.09\times 10^{-113}\) \\ \hline
**Interaction** & \(5.42\) & \(0.000393\) & 71.40 & \(1.85\times 10^{-35}\) & 111.28 & \(1.59\times 10^{-46}\) & 29.07 & \(1.93\times 10^{-18}\) \\ \hline  & & **s3 A** & & **s3 B** & & **s3 C** & & **s3 D** \\ \hline
**p1-3** & \(877.56\) & \(1.2\times 10^{-90}\) & 599.86 & \(5.16\times 10^{-78}\) & 621.09 & \(3.79\times 10^{-79}\) & 654.92 & \(6.96\times 10^{-81}\) \\ \hline
**k1-3** & \(135.90\) & \(4.68\times 10^{-36}\) & 216.88 & \(1.25\times 10^{-47}\) & 551.69 & \(2.61\times 10^{-75}\) & 443.29 & \(2.20\times 10^{-68}\) \\ \hline
**Interaction** & \(106.42\) & \(2.44\times 10^{-45}\) & 42.02 & \(1.65\times 10^{-24}\) & 53.29 & \(4.26\times 10^{-29}\) & 31.77 & \(8.65\times 10^{-20}\) \\ \hline \end{tabular}
\end{table} 
Table 3: The statistical data of the analysis of variance (ANOVA); \(F\)—F test value, \(p_{val}\)—test probability of ANOVA analysis, Deltoid muscle anterior (A) and posterior (B), Triceps brachii (C), Extensor carpi radialis longus (D); markings of the angles of erection of the wheelchair: k1 = 0\({}^{\circ}\), k2 = 1.5\({}^{\circ}\) and k1 = 5.4\({}^{\circ}\); markings of experiment series: s1, s2 and s3; markings of the propulsion system gear ratios: p1 = 1.96, p2 = 1 and p3 = 0.51.