Critics of this simple approach claim that to detect lameness one must specifically and simultaneously observe for many other signs, including movement of the limbs during the swing phase of the stride, cadence of footfall, orientation and placement of the limbs during weight bearing, the apparent ease, comfort, or ability to move in certain gaits, or to transition from one gait to another and other, even more difficult-to-define, signs like head orientation and facial expression.25 I have also observed for most of these signs. In a study tracking the eye movement of veterinary students evaluating videos of lame horses, it was shown that experienced students who concentrated on head and pelvic movement scored significantly better at picking the correct lame limb than inexperienced students who looked at head, pelvis and limb movement and who named a greater number of visual lameness features that they thought were important to track.26 When veterinary trainees are told specifically what to observe, in language clear enough to propose a way to measure it, they can learn to be proficient. Assessment of mild hindlimb lameness during over ground locomotion using linear discriminant analysis of inertial sensor data. Disease-specific changes in equine ground reaction force data documented by use of principal component analysis.