On the estimation of maximum stress in cushions for wheelchair patients who are prone to develop pressure injuries.

Abstract

Pressure injuries are an important health care issue. This problem is even more evident with patients with neurological conditions. This study aims to develop an analytical tool to predict the magnitude of the maximum stresses developed at the wheelchair cushion-patient contact area. Newton's polynomial interpolation method was applied in order to obtain correlations between the maximum stress developed and the weight of the patient and the maximum pressure and body mass index (BMI) of the participants. For this study it was recruited five able-bodies and nine patients with spinal cord injury. The agreement between the computed stress values and those measured with the able-bodied group is excellent, but in the patients within the spinal cord injury group, the concordance is poor. The correlations were applied in data from Crawford's study, and predictions of pressures show lack of agreement. Correlation between the weight of a person and the maximum stress developed by him or her while sitting for extended periods of time has been demonstrated. The lack of agreement between estimated and measured values in spinal cord injuries and Crawford's data can be mainly attributed to some sort of neurological status.