X-ray motion analysis

Depending on the settings of the X-rays, this technique can visualize specific structures in an object, such as bones or cartilage.

The ability to measure skeletal motions is a key aspect to one's understanding of vertebrate biomechanics, energetics, and motor control.

Movements are performed parallel to the camera's imaging plane in order for the motion to be accurately tracked.

[2] In gait analysis, planar X-ray studies are done in the sagittal plane to allow for highly accurate tracking of large movements.

[3] Methods have been developed to allow for estimating all six degrees of freedom of movement from a planar X-ray and a model of the tracked object.

Accurately capturing and quantifying all three dimensions of movement requires a biplanar imaging system.

[6] This method requires surgical procedures for implanting and a healing period before the subject can undergo a motion analysis.

[2][4][6][8] The markers are then tracked relative to the X-ray camera(s) and the motions are mapped to the local anatomical bodies.

[7] The translations and rotations of the model, as opposed to a set of markers, are then tracked relative to the X-ray camera(s).

However, biplanar analysis requires that all tracking be done on both video frames at the same time, positioning the object in free space.

[12] X-ray motion analysis can be utilized in joint imaging or analyzing joint-related diseases.

Aside from locomotion, X-ray motion analysis has been utilized in the study and research of other moving morphology analyses, such as pig mastication[2] and movement of the temporomandibular joint in rabbits.