Joint kinematics obtained by the Microsoft Kinect Sensors are
measured based on a simplification of the human anatomy, which don’t
include anatomically accurate estimations of the joint centers.
Consequently the measured joint kinematics are not directly
compatible with the anatomically accuracy of musculoskeletal models.
Accordingly, the purpose of the present study was to propose a new
marker-less tracking approach using the Microsoft Kinect v2 to obtain
the 3D movement of a single leg. A subject specific articulated model
of the right leg with anatomically correct joint centers was generated
using the Microsoft Kinect v2 to scan the anatomical geometry of the
segments. The poses of the detailed articulated model was estimated
relative to a dynamic depth recording of a 90 degree hip flexion
movement, using an iterative closest point algorithm to which a
constrained optimization problem was defined. The proposed approach
was compared to a marker-based system. Hip flexion/extension,
abduction/adduction, external/internal, knee flexion/extension and
ankle plantar/dorsi flexion were measured for one subject. The
flexion/extension and internal/external rotation for the hip and
flexion/extension for the knee showed good agreement with the
marker-based results. The hip abduction/adduction and ankle
flexion/extension showed poor results compared to the marker-based
system.