Accuracy evaluation of a method to partition ground reaction force and center of pressure in cane-assisted gait using an instrumented cane with a triaxial force sensor

Clarifying the biomechanics of cane-assisted gait in elderly individuals and patients with gait disorders is important for developing better therapeutic interventions in the fields of rehabilitation and orthopedics. However, if the foot and the cane in the ipsilateral hand are placed on the same force plate simultaneously, the force plate cannot separate the forces as it records the sum of the forces. To overcome this indeterminacy problem of the ground reaction force (GRF) and the center of pressure (COP) in cane-assisted gait analysis, a method to partition the GRF and COP using an instrumented cane with a force transducer has been proposed. However, the accuracy and precision of the estimated GRF and COP has not been evaluated previously. We therefore reestablished a framework to partition the foot and cane forces during walking using an instrumented cane with a triaxial force sensor and evaluated the accuracy and precision of the method using a force plate array. Cane-assisted gait of healthy adults and hemiplegic patients were measured. Mean accuracy and precision associated with the GRF and COP measurements were approximately 0.4 ± 1.4 N and 0.2 ± 2.7 mm, respectively, indicating that the separations of the GRF and COP were sufficiently accurate for kinetic gait analysis. Although some methodological limitations certainly apply, this system will serve as a useful tool for improved therapeutic interventions.