The goal of rehabilitation therapy, according to the NYU Langone Medical Center, is to restore function of the involved joint or muscle so that patients can perform functional activities in accordance with their individual goals. New research in the field of rehabilitation has recently begun to explore the anti-gravity treadmill as a new tool for achieving positive patient outcomes. So far, all signs point forward.
What Is An Anti-Gravity Treadmill?
AlterG bills itself as “the next stride in physical therapy and athletic training,” yet the anti-gravity treadmill is not a new idea by any means. Originally conceived over 20 years ago, Dr. Robert Whalen and Dr. Alan Hargens developed the idea while designing an effective exercise program for use on the space station by NASA’s astronauts. NASA had found by studying astronauts returning from space that bone loss and muscle deterioration were a consequence of lack of gravity. To mimic the feeling of gravity, Whalen and Hargens used Differential Air Pressure (DAP) technology to create a machine that sucked air out of a chamber in which the runner exercises.
The AlterG treadmill essentially does the reverse and pumps air into a chamber to counteract gravity. In this way, DAP technology “unweights” a user and so reduces the impact of walking or running on both muscles and joints. In practical terms, while on the AlterG, a patient weighs less so that stress and impact are significantly reduced during exercise. In turn, this experience of carrying less load enables patients to maintain their natural gait while rehabilitating and may even speed the process of therapy.
In Guidelines for Using the AlterG: Patients with Orthopedic Problems, the chief medical officer and clinical specialist of AlterG, Inc. explain how “unweighting an individual to the appropriate loads” may:
- decrease pain and minimize swelling in the early stages of recovery
- increase hip, knee, and ankle mobility by encouraging assistive range of motion
- progressively load the lower extremities to assist with strength, endurance, and neuromuscular re-education
- increase cardiovascular and muscular endurance in the later recovery stages of recovery
- initiate weightbearing activities earlier
Using AlterG, a physical therapist sets the parameters for "unweighting," treadmill speed, treadmill incline, and duration/frequency of treatment, based on the patient’s ability to bear weight. Progressively, these parameters are adjusted so that a patient gradually improves over time.
Does It Work?
In one study published earlier this year, researchers examined anti-gravity or “lower body positive pressure” (LBPP) treadmills to understand if they have the potential to enhance recovery following lower limb surgery. Through an extensive experiment that involved implanting custom electronic tibial prostheses to measure forces in the knee in subjects, the researchers monitored tibiofemoral forces while subjects exercised on a treadmill at certain speeds, inclines, and pressure settings (that reduced body weight up to 25 percent).
What did the team decide? After making a series of adjustments in speed, incline, and pressure setting for each of the subjects, the researchers determined that the anti-gravity treadmill “allows for more precisely achieving the target knee forces desired during early rehabilitation.” The anti-gravity treadmill, then, “might be an effective tool in the rehabilitation of patients following lower-extremity surgery,” the authors wrote in their study.
Sports therapists as well as sports trainers have already incorporated anti-gravity into their sessions. There’s an Instagram photo of Kobe Bryant running on an AlterG and tweets of Eddy Lacy (Green Bay Packers) and Barrett Jones (St. Louis Rams) following suit. Since American professional athletes probably have the most expensive, if not the best, sports programs in the world, you can bet that anti-gravity treadmills must be living up to their claims of offering 'remarkable' recovery times.
Reason alone suggests the anti-gravity treadmill, with its ability to progressively re-introduce weight as an injured patient exercises, is an excellent tool for rehabilitation. Although very few studies have been conducted so far, only positive comments have been made and meanwhile therapists and researchers continue to study the impact on real patients. If nothing else, anti-gravity treadmills sound like the next wave in gym exercising.
Running with a lot less impact on my knees? Sign me up!
Source: Patil S, Steklov N, Bugbee WD, et al. Anti-gravity treadmills are effective in reducing knee forces. Journal of Orthopedic Research. 2013.