Dynamic Unweighting: Anti-Gravity Systems for Rehabilitation

People come to rehabilitation clinics or physical therapists due to a variety of conditions, including obesity, stroke, joint replacements, or sports-related injuries including ligament sprains and meniscal tears.

For many of these people, weight-bearing exercise, particularly walking, can be extremely challenging. In many cases, it can pose safety concerns for both the patient and the assisting clinicians.

Despite the difficulties such patients may face, however, weight-bearing activities are often an essential component to their recovery. Clinical trials and other studies show that weight-bearing activities improve strength, balance, and other important components of functional mobility.

For many clinic owners and physical therapists, the question becomes:

How can I provide my patients with safe and effective opportunities for weight-bearing activities without imposing unnecessary risk, while at the same time garnering an effective treatment response that will elicit physiological change and progress?

Dynamic unweighting, also known as body-weight support training or anti-gravity training, provides a cost-effective and evidence-based solution to this quandary.

What are the benefits of an Anti-Gravity System?

Body-weight supported rehabilitation, including treadmill training or overground walking, has a variety of scientific data to support its safety and efficacy. It's been used in everything from stroke rehabilitation to sports injury recovery for professional athletes.

Aside from improving things like gait quality, balance, coordination, joint integrity, and strength, many clinicians find that anti-gravity devices are a more feasible option for their clinical practice compared to aquatic therapy devices, including pools and underwater treadmills, which can take up considerably more space, time (due to upkeep and maintenance), and financial resources.

Anti-gravity systems may also benefit clinicians and clinic owners from a marketing perspective.

Being able to offer a community this relatively unique type of rehabilitation tool may attract interest from local physicians, surgeons, and sports teams who are looking for trustworthy and high-quality resources to refer their parties to. 

As for the patients themselves, many of them may find that anti-gravity systems provide a highly motivating and engaging way to work on their impairments.

This type of rehabilitative tool can help them maximize their function and activity tolerance while minimizing pain, and may help them return to work or return to play more quickly. 

Additionally, bodyweight support systems can provide patients the physical and mental sense of support and safety, thereby minimizing their fearfulness of falling which could otherwise impose self-limiting behaviors during therapy.

Frequently Asked Questions

The following are a few of the most frequently asked questions by both patients and providers about anti-gravity training systems:

How do anti-gravity systems work?

Unlike patient lift systems that are intended to perform most or all of the work during transfers, anti-gravity systems help patients by partially supporting their bodyweight while they perform functional activities, such as walking or running.

Consequently, an anti-gravity system reduces the amount of load imposed through the body during weight-bearing activities. These systems can unweight a person by up to 80% or more of their bodyweight, and (because individuals are generally supported in the device) prevent falls during challenging gait and balance activities.

There is quite a degree of versatility in the type of anti-gravity systems available on the market but most have a few specific features and designs, including an adjustable harness to support a person's body weight and rails and/or bars for upper extremity support as needed.

Depending on the design of the device, some anti-gravity systems come with caster wheels and locks for overground travel, while others come with a treadmill directly installed. Still others can be used for both treadmill training and overground walking.

Which anti-gravity system is right for my clinic and patient population? 

Special considerations to be made before purchasing an anti-gravity system for an individual clinic include the following:

  • Typical patient population (e.g., pediatric, bariatric, orthopedic, neurological, or a combination of these and others)
  • Projected frequency of use
  • Amount of clinic space that would be able to be dedicated to set-up and placement of the anti-gravity device, especially if it features an overground capability
  • Whether clinicians prefer manually adjusted systems or pneumatic/motorized systems 

Understandably, different products may be more or less successful at meeting these specific needs. Investing a little time in research prior to purchase can help ensure the best choice is made so that the device will be put to good clinical use.

What kinds of injuries can be treated with anti-gravity systems?

Manufacturers of anti-gravity systems, individual practitioners, as well as various research studies have found that anti-gravity systems can enhance and assist with recovery from a variety of injuries and conditions. These include, but are not limited to, the following:

  • Balance and gait impairments caused by cerebrovascular accidents, vestibular impairments, traumatic brain injury, Parkinson's disease, and other neurodegenerative conditions
  • Post-surgical recovery from procedures including total knee arthroplasty, total hip arthroplasty, and spinal fusions
  • Complex regional pain syndrome (CRPS)
  • General deconditioning, failure to thrive, and debility, including frailty among elders
  • Low back pain
  • Plantar fasciitis, Achilles tendonitis, stress fractures, ligament sprains, meniscus tears, shin splints, and other forms of leg and foot pain
  • Obesity and weight-loss 
  • Osteoarthritis and rheumatoid arthritis
  • Osteoporosis and osteopenia
  • Pediatric conditions including Down syndrome, cerebral palsy, and spinal cord injury 

What does the research say about anti-gravity training systems?

While more and larger studies need to be done to fully clarify the benefits and effectiveness of anti-gravity/bodyweight supported training systems, there is data to show that when properly prescribed, these systems are both safe and effective.

For instance, a 2016 randomized controlled study published in Annals of Physical and Rehabilitation Medicine found that bodyweight supported treadmill training elicited better outcomes in outcome measures for stroke patients (including walking endurance) compared to normal treadmill training and overground training. The authors of the study comment that these improvements were not statistically significant. However, the study was limited by a small initial sample size (n=45) and a significant attrition rate, with only 40 participants completing the training and only 34 participants remaining at a 3-month follow up.

Another systematic review published in the November 2010 issue of the Journal of Neurologic Physical Therapy found that bodyweight support yielded small but positive effects in gait quality, activity tolerance, and level of participation in the pediatric populations affected by conditions including central nervous system disorders such as cerebral palsy and spinal cord injuries.

Overall, the consensus appears to be that more extensive research will benefit clinicians interested in using anti-gravity training in their rehabilitation practice. However, there is enough evidence to say that it is at least effective and safe for a wide variety of patient populations, and therefore may be able to enhance patient outcomes for individuals of different ages and health backgrounds.

Anti-Gravity Systems Offered by RehabMart

The following are the main anti-gravity systems offered on RehabMart. These devices and systems have several similarities and differences and can accommodate a variety of different facilities and patients:

  • PhysioGait: offers overground and treadmill walking capability while non-manually off-loading some or all of a patient's bodyweight, as well as a 360 degree turning radius on the yoke for ease of use 
  • PneuLift Unweighting Exercise System: with a flexible yoke system, this device permits bodyweight supported squats and other dynamic, multi-joint movements
  • PneuWalker2 Mobility Trainer: slightly larger in design, this trainer can accommodate larger patients and also assist with basic sit-to-stand transfers in addition to walking; it includes a rechargeable battery that has up to a 12-hour battery life along with a width-adjustable base to allow for transitions through doorways and unilateral unloading for hemiparetic assistance
  • LiteGait MX Gait Trainer: designed for children and adolescents, this trainer comes with acutators to increase the ease with which patients move from wheelchairs into standing
  • Pediatric LiteGait Mobility Frames: featuring a non-powered manual yoke system, this device can be used for a variety of functional purposes including walking, balance training, posture re-training, and standing endurance

Conclusion

Anti-gravity systems, also known as bodyweight support systems, have been around for several years in the rehabilitation world, and research is ongoing to better clarify their overall effectiveness and utility.

Many clinic owners, physical therapists, and others within the allied health field find that these systems offer a variety of training and recovery benefits to their patients, while at the same time improving their safety and the safety of their staff.

When deciding whether to purchase an anti-gravity system, it's helpful to understand the different features of every available option and compare these features to the specific needs of the clinic or therapist.

With nearly half a million satisfied customers (and growing), RehabMart is proud to be a leading provider of safe, effective, and economical rehabilitation tools and products that can enhance patient outcomes and workflow at a variety of clinics.

To learn more about our anti-gravity systems or to find out about our other services, visit RehabMart today, or check out our full library of resources on Caregiver University.

Author:

Sara McEvoy, PT, DPT, is a licensed and board-certified Doctor of Physical Therapy. She has direct clinical experience within the long-term acute care and skilled nursing settings, and has a special interest in geriatrics and neurological rehab. She is also a freelance writer who creates content almost exclusively within the health and wellness fields.

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