EchelonVAC Below-Knee Prosthesis: Hydraulic Ankle with Integrated Vacuum Suspension

The EchelonVAC below-knee prosthesis is an "all-in-one" solution combining a hydraulic ankle joint with an integrated vacuum pump for the socket, offered by Lê Hoàn Prosthetics & Orthotics for below-knee amputees. This design brings together the essential features of a modern prosthesis in a single unit, delivering a stable, near-natural feel.

The carbon foot with integrated hydraulic ankle joint absorbs force at heel-strike and returns that energy before the foot lifts off the ground — a mechanism that produces a softer, more natural gait while reducing the impact forces transmitted up through the knee, hip and lower back, helping users conserve energy while walking. The hydraulic mechanism also automatically adjusts the ankle's flexion angle to match sitting, standing or walking posture, keeping the foot fully in contact with the ground even on slopes, which improves safety and helps prevent trips and falls.

Another standout feature of EchelonVAC is its vacuum pump built directly into the ankle joint, creating negative pressure that secures the residual limb to the socket more firmly and safely. Vacuum-Assisted Socket Suspension (VASS) technology is now widely used across developed countries such as the UK, the US and Europe. Studies comparing vacuum suspension with traditional pin suspension systems suggest that vacuum suspension tends to help maintain residual-limb volume more stably and reduce pistoning — the sliding movement of the limb within the socket during walking — although the degree of improvement can vary between studies. Clinically, this system has also been associated with reduced limb shrinkage over time, helping extend the usable life of the prosthesis.

Notably, Lê Ngọc Hoàn, MSPO — founder of Lê Hoàn Prosthetics & Orthotics — published research on a running prosthesis using a vacuum-assisted socket system in the international journal JPO: Journal of Prosthetics and Orthotics (2021). The study, involving an amputee runner, found no significant difference in running speed between the VASS and non-VASS prosthesis, but the VASS system provided clear benefits in comfort, proprioception and residual-limb volume stability during high-intensity activity.

Alongside EchelonVAC, Lê Hoàn also offers running prostheses for users who want to run or play sports at a competitive or recreational level, tested and fine-tuned using real-world speed and energy-expenditure measurements.

For advice on the below-knee prosthesis best suited to your activity level, contact Lê Hoàn Prosthetics & Orthotics at hotline 0985211888.