However, the lever propulsion with gear ratio 1/1.5 is equivalent to much longer virtual moment arm.
Sequentially, the virtual moment arm for the lever propulsion with gear ratio 1.5 was 1.05 (the ratio of the moment arm/gear ratio = 1.57/1.5), which is almost the same as the virtual moment arm for the lever propulsion.
Results show that during lever propulsion with a gear ratio of 1.5 the intersegmental forces are greater than the intersegmental forces for lever propulsion with gear ratios 1 and 1/1.5.
This result also shows that lever propulsion on a gear ratio of 1.5 can reduce shoulder joint contact force up to 40%% compared to handrim propulsion.
It was also observed that lever propulsion on a gear ratio of 1 reduced shoulder joint contact force up to 60%% compared to handrim propulsion.
For the experiments, we developed a special mechatronic wheelchair simulator that allows simulation of lever propulsion on various gear ratios and road inclinations.
For the new tests, the existed simulator was upgraded to allow simulation of lever propulsion on various gear ratios and road inclinations.
Result showed that the shoulder joint contact force during lever propulsion with a gear ratio 1/1.5 was up to 70%% lower than the shoulder joint contact force during handrim propulsion.
It was observed that for inclination angles of 2° and 4°, the cadence during the lever propulsion on a gear ratio of 1 was almost the same as the cadence of handrim propulsion (Fig. 6).
