Gait
Also known as: gait cycle, walking pattern
Gait is the pattern of movement used in walking, described as a repeating gait cycle from one heel strike to the next heel strike of the same foot. Each cycle divides into a stance phase, when the foot is on the ground, and a swing phase, when it is not.
Gait is analyzed as a cycle rather than a single motion. One gait cycle runs from initial contact of one foot to the next initial contact of that same foot. Roughly 60% of the cycle is the stance phase, when the limb bears weight, and about 40% is the swing phase, when the limb advances through the air. Because the two limbs are out of phase, there are two brief periods of double limb support per cycle — a feature that disappears in running, which substitutes a float phase in which neither foot is down.
Stance subdivides into initial contact, loading response, midstance, terminal stance, and pre-swing; swing subdivides into initial swing, midswing, and terminal swing. Several measurements describe the pattern quantitatively: step length is the distance from one foot's contact to the opposite foot's contact, stride length covers a full cycle and equals two step lengths, cadence is steps per minute, and gait speed is the product of cadence and step length. Slowed gait speed is a well-established marker of functional decline in older adults.
Deviations from normal gait often point directly to a specific impairment. Weak hip abductors produce a Trendelenburg gait, in which the pelvis drops on the unsupported side or the trunk leans over the stance limb to compensate. Weak ankle dorsiflexors produce a steppage gait with excessive hip and knee flexion to clear a dropped foot. Pain shortens the stance time on the affected limb, giving an antalgic gait. Cerebellar dysfunction produces a wide-based ataxic gait, Parkinson disease a shuffling, festinating pattern, and hemiplegia after stroke a circumducted swing. Orthotics, prosthetics, and assistive devices are commonly prescribed to address these deviations.
Gait analysis is heavily tested on the NPTE for both physical therapists and physical therapist assistants, where questions link a described deviation to the responsible muscle or lesion. The NCLEX approaches the same material from the nursing side, focusing on safe ambulation, fall risk, and correct use of canes, walkers, and crutches.
Key takeaways
- One gait cycle spans initial contact of a foot to the next initial contact of the same foot.
- Stance phase is about 60% of the cycle and swing phase about 40%, with two periods of double limb support.
- Stride length equals two step lengths, and gait speed is the product of cadence and step length.
- Trendelenburg gait indicates hip abductor weakness, steppage gait indicates dorsiflexor weakness, and antalgic gait indicates pain in the stance limb.
- Running differs from walking by eliminating double limb support and adding a float phase.