Orion3 MPK

From the recent and independent OASIS study of 602 patients, it was concluded that Orion3 is one of the only MPKs proven to significantly reduce the rate of injurious falls and had a high level of patient satisfaction.


Why Microprocessor Control?

Microprocessor control more accurately mimics the natural movement and behavior of muscles which allows the user to remain perfectly balanced across a range of activities. This not only promotes safety and long-term health but also enables a natural walking experience.


“Because Orion3 is so easy to use it doesn’t drain me of energy, leaving me with more energy to do other things”

How Does Orion3 Work?

The innovative technology powering Orion3 increases the user’s confidence and independence, reducing the risk of stumbles or falls and ensuring more balanced limb loading for greater long term health and protection. 


Stair Descent
Supported Sitting

Orion3 Clinical Evidence

In addition to the recent and independent OASIS study of 602 patients, there is extensive research into Orion3 Microprocessor Technology showing significant improvements to patient quality of life.

  • Significantly reduced number of falls1,2
  • Reduced center-of-pressure fluctuations by 9-11% with standing support active when standing on sloped ground3
  • Less cognitive demand during walking, leading to reduced postural sway4
  • Increased walking speed5
  • Easier to walk at different speeds6
  • Higher scores in mobility-related patient-reported outcome measures7
  • More natural gait6,8
  • Easier to walk on slopes6
  • Reduced energy expenditure compared to mechanical knees9-13
  • Equivalent energy expenditure to other MPKs14
  • Reduced self-perceived effort6,8
  • Energy expenditure closer to that of able-bodied control subjects15
  • Able to walk further before becoming tired6
  • Better step length symmetry5
  • Reduced loading asymmetry with standing support active when standing on sloped ground3
  • Reduced fear of falling1
  • Reduced limitations due to an emotional problem8
  • Preference over other prosthetic knees1,14
  • Reductions in direct and indirect healthcare costs when using an MPK16
1. Kaufman KR, Bernhardt KA, Symms K. Functional assessment and satisfaction of transfemoral amputees with low mobility (FASTK2): A clinical trial of microprocessor-controlled vs. non-microprocessor-controlled knees. Clin Biomech 2018; 58: 116–122.  
2. Campbell JH, Stevens PM, Wurdeman SR. OASIS 1: Retrospective analysis of four different microprocessor knee types. Journal of Rehabilitation and Assistive Technologies Engineering. 2020;7:2055668320968476.  
3. McGrath M, Laszczak P, Zahedi S, et al. Microprocessor knees with ‘standing support’ and articulating, hydraulic ankles improve balance control and inter-limb loading during quiet standing. J Rehabil Assist Technol Eng 2018; 5: 2055668318795396.  
4. Heller BW, Datta D, Howitt J. A pilot study comparing the cognitive demand of walking for transfemoral amputees using the Intelligent Prosthesis with that using conventionally damped knees. Clin Rehabil 2000; 14: 518–522.  
5. Chin T, Maeda Y, Sawamura S, et al. Successful prosthetic fitting of elderly trans-femoral amputees with Intelligent Prosthesis (IP): a clinical pilot study. Prosthet Orthot Int 2007; 31: 271–276.  
6. Datta D, Howitt J. Conventional versus microchip controlled pneumatic swing phase control for trans-femoral amputees: user’s verdict. Prosthet Orthot Int 1998; 22: 129–135.  
7. Wurdeman SR, Stevens PM, Campbell JH. Mobility analysis of amputees (MAAT 3): Matching individuals based on comorbid health reveals improved function for above-knee prosthesis users with microprocessor knee technology. Assist Technol 2018; 1–7.  
8. Saglam Y, Gulenc B, Birisik F, et al. The quality of life analysis of knee prosthesis with complete microprocessor control in trans-femoral amputees. Acta Orthop Traumatol Turc 2017; 51: 466e469.  
9. Chin T, Sawamura S, Shiba R, et al. Energy expenditure during walking in amputees after disarticulation of the hip: a microprocessor-controlled swing-phase control knee versus a mechanical-controlled stance-phase control knee. J Bone Joint Surg Br 2005; 87: 117–119.  
10. Datta D, Heller B, Howitt J. A comparative evaluation of oxygen consumption and gait pattern in amputees using Intelligent Prostheses and conventionally damped knee swing-phase control. Clin Rehabil 2005; 19: 398–403.  
11. Buckley JG, Spence WD, Solomonidis SE. Energy cost of walking: comparison of “intelligent prosthesis” with conventional mechanism. Arch Phys Med Rehabil 1997; 78: 330–333.  
12. Taylor MB, Clark E, Offord EA, et al. A comparison of energy expenditure by a high level trans-femoral amputee using the Intelligent Prosthesis and conventionally damped prosthetic limbs. Prosthet Orthot Int 1996; 20: 116–121.  
13. Kirker S, Keymer S, Talbot J, et al. An assessment of the intelligent knee prosthesis. Clin Rehabil 1996; 10: 267–273.  
14. Chin T, Machida K, Sawamura S, et al. Comparison of different microprocessor controlled knee joints on the energy consumption during walking in trans-femoral amputees: intelligent knee prosthesis (IP) versus C-leg. Prosthet Orthot Int 2006; 30: 73–80.  
15. Chin T, Sawamura S, Shiba R, et al. Effect of an Intelligent Prosthesis (IP) on the walking ability of young transfemoral amputees: comparison of IP users with able-bodied people. Am J Phys Med Rehabil 2003; 82: 447–451.  
16. Chen C, Hanson M, Chaturvedi R, et al. Economic benefits of microprocessor controlled prosthetic knees: a modeling study. J Neuroengineering Rehabil 2018; 15: 62.


Complimentary Ankles

Orion3 works well in combination with our hydraulic ankle technology. By aligning to the terrain and remaining dorsiflexed for swing, our hydraulic ankles provide a smooth, safe and natural walking experience, helping to preserve the body for the long term.

Microprocessor Ankles

Hydraulic Ankles


Hydraulic Ankles for K2 Patients


Request Training & Demo

If you’d like to find out more about Orion3, to arrange training, product demonstrations or trials then please complete the form below and one of our team will get back to you.