What is movement analysis?
Movement analysis is facilitated by the acquisition of objective data that describes a subject’s movement and a physical examination and relevant medical history. Any movement can be studied but the most common clinical analysis is of walking.
Walking involves complex neurological control of limb movements. People with walking difficulties often have different ways of coordinating their movements and adapting to their walking limitations. Clinical gait analysis is used to help understand pathology that affects gait.
Pathologies studied by clinical gait analysis include cerebral palsy, spina bifida, talipes, stroke and amputees. The resulting information can assist clinicians in making decisions about the patient’s management.
Research into human movement is greatly enhanced by the use of an objective tool such as movement analysis, allowing repeated assessment under different conditions. It encompasses many areas including fundamental studies of muscle activity and function, as well as more applied areas such as rehabilitation, development of prostheses and ergonomics. Sports and exercise science is another major area with studies of human movement in athletics, golf and other activities.
A variety of equipment is available for analysis of human movement:
2D video analysis: high quality video footage of coronal (frontal) and sagittal (side) views is included in clinical gait analysis. Video provides a record of the overall gait style and functional ability.
3D computerised analysis: markers are placed on the legs and pelvis and their positions as the subject walks along a walkway are recorded by cameras. By computing the 3D position of the markers the movement of the subject can be regenerated. From this the position of the limb segments and the angles at the joints (kinematics) can be calculated. The kinematics for normal walking are distinctive. The results from subjects with gait disorders can be compared to these to help diagnose the problem and decide a treatment.
Force measurement: The force applied to the floor during walking is measured using one or more forceplates embedded in the floor of the walkway. By combining this with the 3D information, a biomechanical model can be used to find the moments and powers (kinetics) acting at the joints.
Muscle activity and energy cost: electromyography (EMG) equipment can be used to record muscle activity during walking using surface electrodes. Measurements of oxygen consumption or heart rate may be used as a measure of energy consumption.