By Greg Gargiulo
A balance training program featuring a virtual reality feedback component improves postural stability and coordination in patients with diabetic peripheral neuropathy (DPN), which may in turn reduce their risk of falling, according to a study published in the November-December 2013 issue of the Journal of the American Podiatric Medical Association.
DPN is associated with balance deficits and a number of gait abnormalities that are also associated with an increased risk of falls. Research supports the effectiveness of balance training to improve postural stability; however, there may be some drawbacks to the use of conventional exercises in the DPN population, according to Bijan Najafi, PhD, director of the interdisciplinary Consortium on Advanced Motion Performance at the University of Arizona in Tucson.
“Patients with DPN may not be able to perform conventional exercises correctly, and many existing exercises do not incorporate visual feedback, which is critical given the impaired proprioception associated with DPN,” Najafi said.
The repetitive nature of exercise programs can lead to poor compliance in any population, and Najafi believes certain conventional exercises can be overtaxing for DPN patients, which could also negatively affect compliance.
Incorporating virtual reality into a treatment protocol has been effective for improving balance and strength in some older populations (see “Ready Patient One: Exer-gaming for rehabilitation,” April 2013, page 16), but not all patients have responded positively to such interventions, and the concept had not yet been evaluated in patients with DPN.
Therefore, Najafi and colleagues conducted a pilot study involving 29 participants (mean age 57 years) with type 2 diabetes and confirmed DPN and who could walk a minimum of 100 feet independently. Patients performed a series of ankle-based point-to-point reaching tasks, assisted by visual feedback from a virtual reality interface that used sensors on the lower back and calf. Patients followed a virtual avatar on a computer screen and adjusted their movements to best match colored icons that promoted optimal form and timing.
After the 15-minute intervention, researchers found that sway was reduced from baseline in both eyes-open and eyes-closed bipedal balance assessments, but the results were only statistically significant with eyes closed, specifically for center of mass (22%) and for ankle (10%) and hip (12.7%) in the anteroposterior direction. The postural coordination between ankle and hip joints was also significantly improved post-training compared to baseline (10.4% improvement in the anteroposterior direction).
These findings support virtual reality with balance training as an effective intervention for improving postural stability in DPN patients, Najafi said.
While other exer-gaming systems generally have a broad appeal, the exercises in this virtual reality program were specifically designed for DPN patients and their limited abilities, with a focused goal of encouraging them through feedback to move in the most beneficial way.
“The difference is we create the benefit from game features to trigger the enthusiasm of the patient to continue the exercises, and the patient can perceive the error that they’re making,” Najafi said.
In addition, the exercises don’t require much dedicated space and can be performed anywhere that can accommodate a computer or TV screen, even in a patient’s home. Larger screens are recommended for patients with vision problems.
James Richardson, MD, a professor of physical medicine and rehabilitation at the University of Michigan in Ann Arbor who has studied balance and DPN, believes certain components of the intervention hold some promise.
“I think the technology assures that the subjects are indeed moving their ankles in a weight-bearing posture, and that cannot be bad and is likely good. Also, if the technology allows improved patient interest, then that is good as well,” Richardson said.
However, Richardson urges caution in analyzing the study’s results due to the lack of a control group and the bipedal nature of the balance assessment. His 2001 study supports the use of hip strengthening exercises to compensate for impaired ankle proprioceptive thresholds in patients with DPN.
According to Najafi, a large-scale randomized controlled trial of the virtual reality intervention that confirms the initial findings has already been completed and should be published soon, with additional studies planned for the future.
Najafi B, Grewal GS, Sayeed R. Balance rehabilitation: Promoting the role of virtual reality in patients with diabetic peripheral neuropathy. J Am Podiatr Med Assoc 2013;103(6):498-507.
Richardson JK, Sandman D, Vela S. A focused exercise regimen improves clinical measures of balance in patients with peripheral neuropathy. Arch Phys Med Rehabil 2001;82(2):205-209.