Jan M Polgar

Use of a geared wheelchair wheel to reduce propulsive muscular demand during ramp ascent: analysis of muscle activation and kinematics.

Clark R Dickerson, Jack P Callaghan, Samuel J Howarth, 2010, Clinical biomechanics.

Trunk muscle activity during wheelchair ramp ascent and the influence of a geared wheel on the demands of postural control.

Clark R Dickerson, Jack P Callaghan, Samuel J Howarth, 2010, Archives of physical medicine and rehabilitation.