Ambulatory Knee Load and Physical Activity Monitoring
The project has two main objectives:
1) Development of a remote-sensing measurement system for physical activity and knee joint load monitoring in free-living environments.
2) Development of an ambulatory real-time biofeedback system, driven by human body kinematics and kinetics, and aiming to offload the knee joint load.
Both methods should meet several user requirements, such as portability, ease of use, ergonomic design in terms of comfort, shape, size and weight.
The current state of the art in on-body sensors, including inertial and magnetic measurement units is promising and fast growing. Recent developments in these devices such as decreased size, increased accuracy and sensitivity are creating the ideal conditions for their usage during daily life. However, there are still several technical and practical challenges to overcome.
Previous research suggested a combination of inertial measurement units, mounted on-body, and ground reaction force and torque sensors placed underneath the foot, either in the form of instrumented force shoes or in the form of insoles. In other studies, inverse dynamics techniques using exclusively kinematic data have been found to provide reasonable accuracies, in forces and moments estimation.
In the first part of this project, knee load will be estimated using inertial kinematic and minimal kinetic data using two different processing approaches: firstly with a musculoskeletal model, and secondly including machine learning techniques during various activities of daily living. Finally a biofeedback system will be delivered to investigate the potential application of the system as an ambulatory gait training alternative for clinical or home use.
The initial evaluation of the method will be performed in healthy subjects. However, since the target group of the project is KOA patients, clinically-oriented research studies are required. Firstly, the accuracy and sensitivity of the knee load estimation before and after biomechanical interventions should be examined. Moreover, the clinical outcome of the ambulatory real-time biofeedback system in gait retraining applications will be investigated. The very final goal of the project, is the wider clinical adoption of the technique, in rehabilitation exercises and continuous monitoring of the knee joint function. For this reason, meeting design requirements, defined by patients’ preferences is important during the development stage.