System for routine assessment of walker-assisted gait

Strain gauges were built into the legs of a standard aluminium walking frame to simultaneously record forces in three dimensions from all four legs. Preliminary data from six walker-dependent lower-limb amputee subjects suggests that the primary function of a walking frame during ambulation is to enlist the upper extremities to supplement the lower extremities to support body weight. The amplitude and duration of applied forces varied widely from one patient to another. However, repeated strides of individual patients were quite reproducible. Peak vertical walker forces ranged from 33 to 67% body weight and usually occurred during the swing of the least affected leg. Peaks of this magnitude suggest that proper training and evaluation are particularly important for patients whose muscles, joints, and cardiovascular systems have been compromised by disease or prolonged periods of convalescence. Vertical centres of pressure encroached from time to time upon the borders of the walking frame's base of support. Walker stability and patient safety may have been compromised during these periods. A more complete analysis of the magnitude, direction, and point of application of walking frame forces is required before more specific issues of patient safety and stability can be addressed.