A knee airbag includes a front panel, rear panel coupled to the front panel to define an inflation chamber, and an intermediate panel between the front panel and the rear panel and within the inflation chamber. The intermediate panel is connected to the front panel and the rear panel at various locations between a proximal end and a distal end of the intermediate panel to control an inflated configuration of the knee airbag. First and second suspension portions suspend the proximal end of the intermediate panel between the front panel and the rear panel and are permeable to the passage of inflation gases. The first suspension portion extends between the front panel and the proximal end of the intermediate panel. The second suspension portion extends between the rear panel and the proximal end of the intermediate panel. An inflator for inflating the knee airbag is disposed in the inflation chamber at a proximal end of the knee airbag. An inflation gas diffusing arrangement is disposed in the inflation chamber between the inflator and the proximal end of the intermediate panel.