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AlterG
AlterG | Anti-Gravity Treadmill | Bionic Leg
About AlterG
AlterG is a medical device company established in 2005 that provides products for mobility enhancement, physical therapy, and athletic training. The company's origins trace back to founder Sean Whalen and his father, a former NASA research scientist, who developed the initial prototype of the Anti-Gravity Treadmill in their family garage. The concept was born from Sean's graduate studies in entrepreneurship at Stanford University, where he explored the commercial potential of his father's invention, originally designed to help astronauts exercise in space. The underlying technology, known as Differential Air Pressure (DAP), was developed by NASA to allow astronauts to maintain conditioning in space and was later reverse-engineered by AlterG for terrestrial applications. This patented technology creates a pressurized air chamber around the user's lower body, enabling precise unweighting from 100% to as low as 20% of their body weight in 1% increments. The business model centers on the sale of these high-value medical devices to a diverse client base that includes physical therapy clinics, hospitals, skilled nursing facilities, and professional sports teams. Early adoption by organizations like the Nike Oregon Project and various professional sports teams helped validate the technology and establish a market presence. The company's Anti-Gravity Treadmills received FDA clearance as medical devices in 2008, expanding their use into rehabilitation for lower extremity injuries, post-surgery recovery, gait training for neurological conditions, and conditioning for the elderly. AlterG generates revenue through the sale of its treadmill systems, such as the Pro, Via, and Fit models, which are priced for different segments of the rehabilitation and sports performance markets. The company's product line also includes the Bionic Leg, added after the acquisition of Tiburon Corporation. In August 2023, AlterG itself was acquired by ReWalk Robotics (now Lifeward) for approximately $19 million, a move intended to create a more comprehensive portfolio of neurorehabilitation products. AlterG's core product, the Anti-Gravity Treadmill, offers significant benefits by allowing for pain-free movement and the maintenance of normal gait mechanics during recovery and training. This reduces joint impact, limits downtime from injuries, enables earlier post-operative training, and allows athletes to increase training volume with less risk of stress-related injuries. Advanced models incorporate features like Stride Smart, which provides real-time gait analytics, and digital video monitoring to give users and clinicians immediate visual feedback for faster, more effective results. These systems are utilized in over 4,000 facilities globally, including prominent medical centers like Johns Hopkins Medicine and the Mayo Clinic.
Source: Dealroom company dataAt a glance
- Status
- Operational
- Founded
- 2005
- Headquarters
- Hudson, United States
- Employees
- 36
- Open positions
- None listed
- Dealroom signal
- 35.4/100
- Industry
- Health
- Sub-industry
- Medical Devices
- Sector
- Health Tech & Medtech, Rehabilitation, Neurology, Orthopedic, Wearable, Hard Tech, DT and LS, science-based
- Technology
- Deep Tech
- Business model
- Manufacturing
- Client focus
- b2b
- Investment activity
- 1 company, latest Jun 2013
- Capital deployed
- —
- Preferred round
- ACQUISITION
Knowledge graph
More headlines
Funding history
Company financing events and reported valuations.
| Deal type | Date | Amount | Valuation | Investors | Source |
|---|---|---|---|---|---|
| DEBT✓Debt | Oct 2021 | $8M | — | Cortland Credit Lending Corporation | — |
| Other✓Other financing | Sep 2018 | $0 | — | Partner Ventures | — |
Growth signals
Latest recorded traffic for AlterG is 14K monthly website visits, up 64.7% over the last three months. AlterG's team grew 0% over the past year.
Similar companies
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Investments and acquisitions
Recent portfolio relationships for companies that also act as investors or acquirers.
Investors
From Dealroom's funding and investor records, grouped by the round each investor first entered.
Series A4 investors entered at this stage
- AVAstrolabe Ventures
- RPRed Planet Capital Partners
- FVFunk Ventures
Versant Ventures
Series B and later3 investors entered at this stage
Oxford Finance
Silicon Valley Bank
Cortland Credit Lending Corporation
Other known investors1 additional known investor
Partner Ventures
Source: Dealroom Talent Intelligence.
Global footprint
team presence
Market sentiment
An AI-synthesised read of the highest-engagement posts about AlterG on X, ranked by likes and reposts, corporate channels excluded.
Reading the room on X — pulling top posts and synthesizing themes…
Source: X recent search ranked by engagement (likes + retweets) · Synthesis by Claude · Cached for 1 hour
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