A Rehabilitation Tool for Functional Balance using Altered Gravity and Virtual Reality

The current project is driven by the need for effective and functional treatment of various categories of patients with gait and balance problems. Furthermore, early treatment and mobilization of patients with hip fractures, a common consequence of falls especially in the elderly population, is critical for a successful outcome. Gait training in these populations of patients using partial body weight support (BWS) on a treadmill, a technique that involves unloading the subject through a harness, improves walking better than training with full weight bearing. One problem with the BWS technique that is not commonly acknowledged is that the supporting harness decreases the need for natural postural control. The harness provides an external support partly eliminating associated postural adjustments that are required during independent gait. We have developed a tool that can refine the concept of BWS training by allowing natural associated postural adjustments to occur. While in a supine position in a 90 deg tilted environment built around a modified hospital bed, subjects wear a backpack frame that is freely moving on air-bearings (cf. puck on an air hockey table) and attached through a cable to a pneumatic cylinder that provides a load to emulate G-like loads. Various exercise devices can be used including a treadmill, stepper and bicycle. Veridical visual input is provided through two 3D automultiscopic displays that allow glasses free 3D vision representing a virtual surrounding environment that may be acquired from sites chosen by the patient. A group of 12 healthy subjects were exposed to a combination of strength and balance training in such a tilted environment over a period of 4 weeks. Measures of both isokinetic strength and balance assessed in an upright position showed statistically significant improvements after training with postural measures indicating less reliance on visual and/or increased use of somatosensory cues