The gait cycle is basically our walking or running pattern. It is the way we move from one point to another and is generally the same for all of us, in the way it can be divided into phases.
It’s really important in the assessment of many running injuries as observing the way we run (through gait analysis) can give us many clues as to the cause of an injury.
When talking about the gait cycle, we refer to two main phases – stance and swing. This applies to one leg at a time, so for example we would follow the right leg through one entire cycle which includes one stance and one swing phase. When walking, there is always one foot in contact with the ground and for a short period, both feet are on the floor (toes on one foot and heel of the other). When running, there are times when neither foot is touching the ground, and at no time are both feet in contact.
The Gait Cycle: Stance Phase
This is the part of the cycle where the foot comes into contact with the ground. The first part of this cycle is the heel strike or initial contact. When walking the heel usually hits the ground first. In many runners this is also the case although in runners who do not heel strike, it may be the mid-foot or even the toes that touch the ground first.
At this point in the cycle the knee is slightly bent to help absorb the forces from the impact. Another important factor for runners at this point is pronation, which occurs from initial impact through to the next phase – mid stance. It is perfectly normal and healthy for this to happen at this point as it allows the foot to mould to the surface and for weight to be transferred to the big toe for propulsion.
As the foot flattens on the ground the body weight moves forwards over the foot to ‘mid-stance’. At this point in the he cycle the foot needs to provide support for the whole body as the other foot is off the ground and swinging forwards.
Pronation should have stopped by now, if not, the foot is too mobile and potentially ‘overpronates’.
As the body continues forwards, the heel lifts and the weight is now on the front of the foot ready for propulsion. This is known as toe-off.
As the big toe bends, the windlass mechanism ensures that the fascia under the foot tightens which helps make the foot a rigid structure, ready for propulsion.
The Gait Cycle: Swing Phase
The swing phase starts as soon as the stance phase ends at toe off. At this point the leg is behind the body. Swing phase involves the leg moving forwards ready to take the next step. Again there is a mid-swing point when the knee is at full flexion and the thigh is level with the weight bearing limb. This forward motion continues towards terminal swing where the hip reaches full flexion, and then starts to extend again just before heel strike occurs.
The swing phase of gait tends to be less important to running biomechanics in terms of injuries than the stance phase as there is no weight through the joints and so reduced pressure on all structures. However it can still cause a few injuries. Typically over striding can be a problem which may cause hip and groin problems.