Lui J, MacGillivray MK, Sheel AW, Jeyasurya J, Sadeghi M, Sawatzky BJ. Mechanical efficiency of two commercial lever-propulsion for mechanisms for manual wheelchair locomotion. J Rehabil Res Dev. 2013;50(10):1363–72.http://dx.doi.org/10.1682/JRRD.2013.02.0034

Figure 2. Drag test setup showing wheelchair and subject on treadmill while force transducer measures drag force (F d).