Effects of Wheelchair Cushions and Pressure Relief Maneuvers on Ischial Interface Pressure and Blood Flow in People With Spinal Cord Injury

ObjectiveTo investigate the effectiveness and interactions of 2 methods of pressure ulcer prevention, wheelchair cushions and pressure relief maneuvers, on interface pressure (IP) and blood flow of the buttocks.DesignWithin-subject repeated measures.SettingRehabilitation center.ParticipantsWheelchair users with a spinal cord injury or disorder (N=17).InterventionsParticipants performed 3 forward leans and 2 sideward leans with different degrees of lean while seated on each of 3 different wheelchair cushions.Main Outcome MeasuresIP measured with a custom sensor and blood flow measured with laser Doppler flowmetry were collected at the ischial tuberosity.ResultsPressure relief maneuvers had a significant main effect on the ischial IP (P<.001); all maneuvers except for the small frontward lean resulted in a significant reduction in IP compared with upright sitting. Blood flow significantly varied across postures (P<.001) with flow during upright sitting and small forward leans being significantly lower than during the full and intermediate leans in both the forward and sideward directions.ConclusionsThe results of the study highlight the importance of positioning wheelchair users in a manner that facilitates in-seat movement. Regardless of the cushion being used, the pressure relief maneuvers resulted in very large reductions in IPs and significant increases in buttock blood flow. Only the small frontward lean was shown to be ineffective in reducing pressure or increasing blood flow. Because these pressure relief maneuvers involved postural changes that can occur during functional activities, these pressure relief maneuvers can become a part of volitional pressure relief and functional weight shifts. Therefore, clinical instruction should cover both as a means to impart sitting behaviors that may lead to better tissue health.