Test exercise for a long-term monitoring of unilateral leg amputees in gonarthrosis therapy

Abstract Unilateral leg amputees suffer from an increased risk of gonarthrosis. The risk of substantial joint damage ca be decreased by an early diagnosis, therapy and long-term monitoring to regularly assess the knee joint’s condition. To adapt the acoustic-kinetic analysis to unilateral amputees, a hand rig with Hottinger Quantum X440B and 2SMR sensors was added to the measurement setup. It helps the probands to keep their balance and to achieve a fluent motion during their test exercise of 3 knee bends in 10 seconds. The measurement setup comprises a ZebrisR system to measure the vertical ground force, two Zebris SyncR Cams to assess the sagittal knee angle, the frontal horizontal knee shift and - in case of the amputees- the data of the hand forces via the Hottinger sensors. It is crucial to establish if the test exercise is adequate for the amputees and if the probands can perform the exercise regularly and over a long period of time with less than 10% - 20% variation. To this end a case study out of a pilot study of 18 case conditions and 108 measurements is presented to clarify the approach. The proband is female, 43 years old, with a unilateral amputation at the thigh. She does not suffer from arthrosis. She performed the test routine six times over a period of five weeks. The kinetic analysis resulted in a characteristic pattern, comparable to non-amputated patients. The results showed a good recurrence and therefore indicate that the test exercise of 3 knee bends in 10 seconds with hand support will be the exercise prospective studies.