Summary
Background: An aging population and people’s higher survival to diseases and traumas that leave
physical consequences are challenging aspects in the context of an efficient health
management. This is why telerehabilitation systems are being developed, to allow monitoring
and support of physiotherapy sessions at home, which could reduce healthcare costs
while also improving the quality of life of the users.
Objectives: Our goal is the development of a Kinect-based algorithm that provides a very accurate
real-time monitoring of physical rehabilitation exercises and that also provides a
friendly interface oriented both to users and physiotherapists.
Methods: The two main constituents of our algorithm are the posture classification method
and the exercises recognition method. The exercises consist of series of movements.
Each movement is composed of an initial posture, a final posture and the angular trajectories
of the limbs involved in the movement. The algorithm was designed and tested with
datasets of real movements performed by volunteers. We also explain in the paper how
we obtained the optimal values for the trade-off values for posture and trajectory
recognition.
Results: Two relevant aspects of the algorithm were evaluated in our tests, classification
accuracy and real-time data processing. We achieved 91.9% accuracy in posture classification
and 93.75% accuracy in trajectory recognition. We also checked whether the algorithm
was able to process the data in real-time. We found that our algorithm could process
more than 20,000 postures per second and all the required trajectory data-series in
real-time, which in practice guarantees no perceptible delays. Later on, we carried
out two clinical trials with real patients that suffered shoulder disorders. We obtained
an exercise monitoring accuracy of 95.16%.
Conclusions: We present an exercise recognition algorithm that handles the data provided by Kinect
efficiently. The algorithm has been validated in a real scenario where we have verified
its suitability. Moreover, we have received a positive feedback from both users and
the physiotherapists who took part in the tests.
Keywords
Telerehabilitation - telemedicine - exercise recognition - Kinect-based motion tracking
