Many clients using wheelchair seating have increased muscle tone. This can lead to active extension, particularly at the hips, knees, and neck. When a client extends against a static seating system, the forces exerted against the footplates, seat, back and head support have nowhere to go and this can lead to an actual increase in client extension. As a result, the client may have difficulty tolerating the seating system for a reasonable amount of time (sitting tolerance) and may experience discomfort and even pain. Dynamic seating absorbs and diffuses these extensor forces. Remarkably, this can lead to an actual reduction in extensor tone.