P-Leg Polycentric Pneumatic Knee Joint

Walnut Medical is the first company in India to manufacture Pneumatic Knee joints, fully manufactured in India.

Walnut Medical P-Leg  WM-002        MADE IN INDIA


Specification of Four Bar Polycentric Pneumatic Knee Joint for AK Amputee


Material of Cylinder

Material of Distal tube connector (removable)



Aircraft Grade lightweight Aluminum

Malleable Grade Aluminium



Amputation Level



Above-Knee / Trans-Femoral



Overall Height





Activity Level 2-3

Product Weight



<900 grams


Flexion Angle Connectors 150°
Connectors Proximal – Pyramid

Distal – Tube Clamp (separable connector)

Side Bars SS 316 with Electro-polishing finish
Max Patient Weight 110 Kgs

Extension Assist, Swing Phase control, Extension/Flexion control


Single-chamber pneumatics control the swing phase 

In swing phase, the smooth yet powerful single-chamber pneumatic’s – one chamber each for flexion and extension damping – do not run out of air, even at various walking speeds.

Harmonious flexion and extension movements, and therefore an approximation of the physiological gait pattern, are made possible. Here the joint geometry effectively shortens the prosthesis during swing, resulting in more ground clearance.

Four-axis poly-centric structure ensures stance phase stability

In extension, the instantaneous center of rotation is located above the joint and behind the load line, resulting in high stability in stance phase. The integrated extension assist spring ensures that the lower leg of the prosthesis is always extended at heel strike and weight can be safely supported on

First Pneumatic Knee Joint Designed, Developed and Manufactured in India

German Quality made in India            ISO 10328 13485                                                                   

 Polycentric – 4 Axis – Pneumatic Knee Joint

the prosthesis side. This is especially advantageous when the user takes small compensating steps, turns in a circle or walks in confined areas. The Walnut Medical P-Leg offers numerous advantages, not only whilst walking.

When sitting or kneeling, the large maximum flexion angle of 150° and the low system height when flexed make it both comfortable and practical.

 Easy to fit

Flexion and extension dampening can be separately and individually customized to the needs of the user. This effectively reduces the working time of the prosthetist and leads to rapid fitting success.


  • Treatment of all amputation levels
  • Powerful swing phase control
  • Flexion and extension damping can be easily adjusted independently of the other
  • High stance phase stability thanks to polycentric four-axis joint
  • Robust, durable construction
  • Lightweight aluminum design


Pneumatic Knee Joint