A normal gait occurs when a person’s running or walking cycle is such that the foot properly absorbs shock. If a person does not have a normal gait, pain and other conditions can result. A person’s gait is separated into two phases: the stance phase and the swing phase. During these phases, the foot should hit the ground in a certain way to achieve a proper gait.
The stance phase of a normal gait comprises about 60% of the entire walking cycle, and less for a running cycle. It progresses from the moment a heel touches the ground to the moment the big toe leaves the ground. In a proper gait, the heel will strike the floor on the outside back — that is, the outer posterior — of the foot. After the heel strikes, the middle of the foot hits the ground. As the walk goes on, the foot will elongate and then go rigid to help a person move forward.
If the arch of the foot is too shallow, a person is said to have flat feet. Without a proper arch, the foot is not able to properly propel a person forward, and the hip and knee may not be in proper alignment during walking or running. Flat feet can cause back pain, bunions, calluses, and hammer toe as the body tries to compensate for the incorrect gait. On the opposite side, a person with too much arch may incur trouble because the foot does not flatten enough to absorb the shock exerted on the joints and bones during walking or running. The consequences of this abnormality include susceptibility to shin splits, stress fractures to various bones, and sprained ankles.
In a normal gait, After the middle of the foot hits the ground, the toes strike. Once the entire foot is on the ground, the person must balance on the foot as the other foot moves forward. During this time, the entire bodyweight is on one foot. As the other foot swings forward, the weight of the body is being shifted forward until the other foot hits the ground and the heel of the first foot starts to lift off. At this point of walking, both feet are on the floor in a state called terminal double support, and the body moves its weight from one foot to the other.
The other 40% of a normal gait is the swing phase. During this phase, the foot is swinging forward and preparing to strike the heel and complete the normal gait. Usually, when the foot is leaving the ground, the weight of the body should leave from the area of the little toe to the big toe. This means that in a normal gait, the outside heel should strike the ground first and the big toe should leave the ground last. When running, the float phase — a subphase in which neither foot is touching the ground — is added to the swing phase.