1. A method for capturing motion of an object having a plurality of segments via a plurality of motion sensor modules located on the segments, each of two or more of the segments of the object having thereon at least one motion sensor, each sensor module being adapted to capture 3D position data and 3D orientation data associated with its respective segment, the method comprising: collecting 3D inertial sensor data at each sensor module via at least one 3D accelerometer sensor and at least one 3D angular velocity sensor; and calculating a 3D orientation and 3D position of each segment having a sensor by integrating the 3D angular velocity data and doubly integrating the 3D accelerometer data in time and updating the calculation via constraints based on predetermined characteristics of the segments.