All ADVANCE participants with lower-limb amputations undergo some extra tests when they come to Stanford Hall for their ADVANCE visits. These tests are done mainly to assess the participants’ mobility and how well they are able to perform certain functional movements. We use a tool called the Amputee MobilityPredictor (AMP) to do this.
The AMP is a quick and easy tool, and the tests involved take no more than 15 minutes to do. The tests are slightly different for people with prostheses (AMPPRO tests) and without prostheses (AMPnoPRO tests).
The things we look at with AMP include sitting ability, going from sitting to standing, standing ability and balance, and walking – at different speeds, over obstacles, and up and down stairs. Each function is then scored, and the total score over all the tests is calculated and correlated to the AMP scoring system which has five bands, from K-Level 0 to K-Level 4. K-Level 0 corresponds to minimal mobility and not having the ability or potential to walk or transfer safely without assistance, and a prosthesis does not enhance the quality of life or mobility. K-Level 4 corresponds to very good mobility and having the ability to move very well with a prosthesis.
The AMP is a reliable tool and has a good validity against other commonly used tests, such as a the 6-minute walk test and the Amputee Activity Survey. This means that the AMP can be used widely by different clinicians to get the same scores when testing patients.
As the ADVANCE participants return to Stanford Hall for their follow-up appointments, the AMP is a quick stock check to see how they are faring over the years. It’s an easy assessment and can highlight any issues very quickly. The test leaves little place to hide, so we can see who has good technique with their prostheses (or not!) and how this changes over time. We are also able to look at differences in mobility between unilateral and bilateral amputees, and people with below-knee and above-knee amputations.