gait: one construct, many systems

In the study of animal locomotion, a gait is a characteristic, repeating pattern of limb movements and footfalls, such as a horse's walk, trot, pace, or gallop, that an animal adopts to move efficiently at a given speed, with transitions between gaits as speed changes. Hildebrand's 1965 Symmetrical gaits of horses gave a quantitative classification by the timing and sequence of footfalls, and Alexander's 1989 Optimization and gaits in the locomotion of vertebrates tied gait choice to minimising energy cost. The referent is the periodic coordination pattern of locomotion, measured in duty factor and relative phase of the limbs, the same construct that recurs in human walking and in walking machines.[1][2]

Unit

The relative timing (phase) and duty factor of the limbs during a locomotor cycle

Recovery means

Not applicable

Measured by

Described by footfall timing, duty factor, stride frequency, and gait-transition speeds

In legged robotics, a gait is the prescribed cyclic pattern in which a machine lifts, swings, and places its legs to move while staying balanced, directly inheriting the biological taxonomy of walks, trots, and bounds and the timing variables that define them. Raibert's Legged robots that balance showed how hopping and running gaits could be generated and stabilised by controlling leg thrust, body attitude, and foot placement. It is the identical periodic-coordination construct as animal and human gait, here realised in a control system and measured by the programmed phase relationships and stability of the leg cycle rather than by muscles and footfalls.[3]

Unit

The programmed phase relationships and support sequence of the legs

Recovery means

Not applicable

Measured by

Specified by the leg phase schedule, support pattern, and stability margins of the locomotion controller

In clinical biomechanics, human gait is the cyclic pattern of walking, analysed as a repeating gait cycle divided into stance and swing phases with defined sub-events, so that normal and pathological walking can be compared and treated. Perry and Burnfield's Gait analysis: Normal and pathological function is the standard reference for the phases of the cycle and the muscle actions and joint motions within them. It is the same periodic-locomotion construct seen in animals and in walking robots, specialised to the human and measured by the timing of the gait cycle, joint kinematics, and ground reaction forces.[4]

Unit

The timing of the gait cycle and the joint motions and forces within it

Recovery means

In rehabilitation, recovery of gait means restoring a normal, symmetrical cycle after injury or neurological insult

Measured by

Quantified by temporal-spatial parameters, joint kinematics, kinetics, and electromyography across the gait cycle