Biomechanical analysis is the evaluation of mechanical principles (eg, forces, torque, center of mass, friction, energy, momentum) to biological systems and, in this instance, to animal movement. Kinematics describes motion from a position and time perspective. Kinetics examines causes of motion through linear forces and angular torque or movements. Analysis of biomechanics, kinematics, and kinetics provides an objective element to traditionally subjective lameness evaluations. These techniques can be used to evaluate musculoskeletal and neurologic function, improve performance, evaluate surgical and medical treatments, and facilitate preventive actions.
Techniques include 2D video analysis and 3D motion- capture technology. 3D motion capture isolates the movement of segments in 3 anatomic planes; this enables proper interpretation of joint movements, including the challenging transverse plane. Force plates and goniometry are the most commonly used objective techniques for gait analysis in dogs, but accelerometers are becoming more common. Thermography is used to map skin-surface temperature. Abnormal temperatures can be tracked during movement and can highlight subclinical changes. Although more commonly used in horses, thermography can be used to diagnosis cranial cruciate ligament disease in dogs without stifle laxity.
Field conditions vs clinical environment can play a significant role in biomechanical analysis; anxiety or stress associated with an unfamiliar environment can cause behavioral changes that affect gait.