Mobility classes


Imagine a competitive athlete with amputation who is forced to work out on a prosthesis with a rigid knee. Or an older, more sedentary person using a prosthesis with a "fast" high-performance knee and running foot.

When it comes to prosthetic legs, the component selection needs to be appropriate for the individual and their potential level of functional ability, such as their activity and mobility.

To help determine the ideal prosthetic components for each user, mobility levels have been developed through four classifications known as the "K Levels.“ All prosthetic components are assigned a corresponding K-Level, and based on your personal K-Level, your prosthetist can select the right components for your needs.

Determining your degree of mobility

How do you find your K-Level? Your orthopedic technician or doctor will consider many factors. These include your age, body weight, physical constitution, level of amputation, blunt features, pain, and whether you have any possible comorbidities . Your level is determined based upon your current needs and your anticipated performance in the future.

The four K-Level categories

K-Level 1: Indoor walker

With the help of a prosthesis, it is possible for a person to manage level walking distances at a fixed cadence.

K-Level 2: Restricted outdoor walker

With the help of a prosthesis, it is possible for a person to cope with limited walking distances at low walking speeds. The person can navigate low environmental obstacles such as curbs, steps and uneven floors.

K-Level 3: Unrestricted outdoor walker

With the help of a prosthesis, it is possible to move freely on different types of terrain. The person may walk or have the potential to walk at varying speeds and be able to handle most environmental obstacles. They may be able to pursue therapeutic, occupational, recreational or exercise activities without overstressing their prosthesis.

K-Level 4: Outdoor walkers with particularly high requirements

With the help of the prosthesis, the person can move without restriction, including tolerating high-impact, stress or energy levels. Walking time and walking distance are unlimited. The prosthesis is capable of fulfilling the typical needs of a child, active adult, or athlete.