Motion capture systems are gaining more and more importance in different fields of
research. In the field of biomechanics, marker-based systems have always been used as
an accurate and precise method to capture motion. However, attaching markers on the
subject is a time-consuming and laborious method. As a consequence, this problem has
given rise to a new concept of motion capture based on marker-less systems. By means
of these systems, motion can be recorded without attaching any markers to the skin of the
subject and capturing colour-depth data of the subject in movement. The current thesis
has researched on marker-less motion capture using the Kinect sensor, and has
compared the two motion capture systems, marker-based and marker-less, by analysing
the results of several captured motions. In this thesis, two takes have been recorded and
only motion of the pelvis and lower limb segments have been analysed. The methodology
has consisted of capturing the motions using the marker-based and marker-less systems
simultaneously and then processing the data by using specific software. At the end, the
angles of hip flexion, hip adduction, knee and ankle obtained through the two systems
have been compared. In order to obtain the three-dimensional joint angles using the
marker-less system, a new software named iPi Soft has been introduced to process the
data from the Kinect sensor. Finally, the results of two systems have been compared and
thoroughly discussed, so as to assess the accuracy of the Kinect system.
