Biomechanical effect of changes in walker height and position on sagittal plane elbow dynamics for rehabilitation purposes

Many devices are used to assist in ambulation including crutches, canes, and walkers. Forces applied to these walking aids have been quantified as well as the kinematics associated with each device usage pattern in past research with relative acceptance. In addition kinetics have been described for canes and crutches although walker joint moments and forces have been noticeably lacking. This has been due to the unique problems that the walker´s rigid frame presents in separating the forces applied to each handle. In this paper a unique device has allowed for the examination of forces applied to each side of a subject´s upper extremities. The kinetics of ten healthy subjects are presented while using a standard walker during five prescribed walking conditions with no weight bearing on the right leg. Forces were measured individually on both left and right sides to allow for the calculation of internal joint moments at the elbow in the sagittal plane. It was found that each usage pattern produces different moment magnitudes at the elbow. The higher walker setting and increased forward placement of the walker produced the largest moments. Knowledge about upper extremity kinetics and kinematics during walker-assisted gait may prove beneficial to improve rehabilitation procedures and in the design of future walkers