What is an AlterG Anti‑Gravity Treadmill?

The AlterG treadmill uses differential air pressure (DAP) – originally inspired by NASA to create a sealed lower-body chamber. By changing the air pressure, it accurately reduces a user’s effective bodyweight from 100% down to 20%.

Why it is important in rehabilitation

Progressive Load Management

Users begin at significantly reduced body weight settings (often 20%-50 %), this will minimise joint stress while allowing a natural gait. Over time, body weight support (BWS) is increased by 5–10 % weekly, enabling safe and progressive loading—facilitating early movement after surgery or injury.

Aerobic & Muscular Conditioning

Studies show AlterG exercise maintains reasonable cardiovascular output:

• Runners at AlterG higher settings (60–80 %) sustained maximal VO₂ and extended endurance by ~34 %

• Muscle strengthening around hip and thigh muscles after fractures improved over 4 weeks relative to standard PT.

Injury-Specific Rehab & Pain Management

From Achilles tendon repairs to spinal fuse recovery, AlterG enables safe reintroduction of gait earlier than over-ground rehab or standard treadmills:

• Achilles rehab: 50–70 % BW allowed early closed-chain work
• Lumbar disc herniation: walking at 50 % at one week; full return by week 6
• Pelvic stress in collegiate runner: jogging resumed at week 5 → 45 min at 95% BW by week 8

Neurological & Balance Benefits

Randomised Controlled Trials support neurological rehab using AlterG:

• Stroke rehab: 30 ± 10 % BWS with gait speed progressively increasing to ~1 m/s. AlterG users achieved greater cadence and gait symmetry than conventional treadmill training.
• Burn survivors (18–35 yrs): combined physiotherapy with AlterG sessions saw stride, velocity, cadence improvements of 15–23%, and stability index gains of 48–55%, vastly outperforming controls.
• Diabetic neuropathy: 12-week programme showed greater gait & balance gains compared to standard physiotherapy (significant improvements in walking distance, stability, reduced knee impact).

Clinical Pilot Trials

• After total knee replacement: 4-week of AlterG gait training showed comparable safety and functional improvements (KOOS, timed up & go, pain reduction 2.8→1.1) as land-based rehab, with high therapist satisfaction.
• Femoral fractures: A 4-week programme increased isokinetic strength in gluteus and thigh muscles more than the control group.

What patients have said:

User recovering from ACL reconstruction described major benefits:

“Within a few minutes I went from 50% bodyweight to 85% bodyweight I felt comfortable and gained confidence to stop using crutches.

A runner recovering from back injury:

“It feels more like running the more body percent weight you add. It was super helpful, maintaining fitness, biomechanics and confidence.

Conclusions

The AlterG Anti‑Gravity Treadmill bridges the gap between immobilisation and real-world load bearing by:

• Reducing impact while preserving conditioning.
• Enabling safe reintroduction of gait after injury or surgery.
• Enhancing neuromotor control across diverse patient populations (orthopaedics, neuro, burns, ageing, obesity).
• Improving rehab outcomes: increased strength, gait quality, balance, confidence.

With strong efficacy demonstrated through RCTs and case studies, as well as enthusiastic patient reports—the AlterG is a proven, clinically potent tool in modern rehabilitation.

References

Saxena, A., & Granot, Y. (2011). Use of an Anti-Gravity Treadmill (AlterG) for Rehabilitation Following Achilles Tendon Surgery. Journal of Foot and Ankle Surgery, 50(5), 558–561.
https://doi.org/10.1053/j.jfas.2011.05.004

Tenforde, A. S., Kraus, E., Fredericson, M. (2012). Evaluation and management of stress fractures in female athletes. PM&R, 4(8), 629–631.
https://doi.org/10.1016/j.pmrj.2012.06.007

Powell, D. W., Butterfield, T. A., Wallace, J. A. (2023). Anti-gravity treadmill running improves aerobic fitness following Achilles tendon surgery: A case report. SAGE Open Medical Case Reports, 11.
https://doi.org/10.1177/2050313X231160033

Jiang, S., Yin, Y., Huang, Y., Wang, W., Hu, W. (2024). Effect of Body Weight–Supported Treadmill Training on Walking Ability in Stroke Patients: A Meta-Analysis of Randomized Controlled Trials. Frontiers in Neurology, 15, 1413577.
https://doi.org/10.3389/fneur.2024.1413577

Lee, S. Y., & Kim, S. K. (2024). Effects of Inclined and Speed-Varied Anti-Gravity Treadmill Training on Stroke Rehabilitation. Medicina, 60(4), 542.
https://doi.org/10.3390/medicina60040542

Kim, C. R., et al. (2023). The effectiveness of AlterG treadmill training in post-stroke gait and balance recovery: A 6-week clinical trial. Korean Journal of Neurorehabilitation, 35(2), 75–82.

Grabowski, A. M., & Kram, R. (2008). Running on air: The biomechanics of running on the AlterG treadmill. Medicine & Science in Sports & Exercise, 40(3), 516–522.
https://doi.org/10.1249/MSS.0b013e31815f927c

McNeill, D. K., et al. (2015). Low-Impact Aerobic Training with the AlterG® Treadmill for Morbidly Obese Patients: A Case Series. Archives of Physical Medicine and Rehabilitation, 96(10), e36.
https://doi.org/10.1016/j.apmr.2015.08.112

Ruckstuhl, H., et al. (2009). Cardiopulmonary response to walking with body weight support in healthy subjects. European Journal of Applied Physiology, 106(4), 553–561.
https://doi.org/10.1007/s00421-009-1047-y

Cutuk, A., et al. (2006). Ambulation in simulated fractional gravity using lower body positive pressure: Cardiovascular safety and gait analyses. Journal of Applied Physiology, 101(3), 771–777.
https://doi.org/10.1152/japplphysiol.01352.2005