Walking is a very easy and convenient way of travelling short distances but it relies on a good joint and muscular system and an absence of pain. The efficiency of walking relies on good joint ranges of motion and sufficient muscular power in the lower limb musculature. As we move forward in walking one leg provides the support for the body while the other one moves through to take its place. Gait is divided most simply into swing and stance phases which indicate what position the leg is in at any one time.
The process of going through all the stages and getting back onto the same foot again is known as the gait cycle. Both feet are down on the ground for about 10% of the gait cycle, with a single down on the ground for about 40% percent overall. The remainder is made up of the swing part of the cycle as the legs are being brought through to be placed down on the ground again for the next step. As walking gets faster the duration of these phases of the gait cycle reduces and when we start running then there is no double support phase when both legs are on the ground at the same time.
The leg joints follow a specific and repeatable series of actions during the swing and stance phases with stance made up of five sections in the order of initial contact, loading response, mid stance, terminal stance and preswing. Heel strike is the common name given to initial contact but some people do not heel strike at all or transfer weight to the heel later in the phase. Heel strike allows the leg which is about to weight bear to take the weight but not compromise speed, stability or shock protection.
With one leg supporting the bodyweight the other limb is going through the swing phase. The body moves the centre of support over the foot in what is known as mid stance, the initial part of the phase of single leg support. Terminal stance occurs next as the heel of the supporting foot rises from the ground and finishes as the other leg makes heel strike and begins to support weight. Preswing is really a preparation for the swing phase and begins with the last part of the both leg support phase, finishing when the foot is raised to begin swing. Foot clearance above the ground and the forward motion of the leg to engage another step are the function of the swing phases of initial, mid and terminal swing phases.
For gait to be efficient it must incorporate some control over the conservation of energy and the absorption of shocks which can be adversely affected by changes in joint motions and the loss of muscle power. This can cause increases in the joint contact forces and lead to musculoskeletal problems with the loaded structures. Bodyweight loads very fast onto the heel strike leg, with 60 percent being transferred within 20 milliseconds of the start of early stance phase.
The leg joints absorb and control these forces as they act as shock absorbers and dampers. When the leg is placed initially on the ground the forward forces involved tend to make the knee bend so we resist this by making the knee straighter even though this increases the forces through the joints. Loading forces are minimised by eccentric muscle action by the hip adductors and quadriceps.
The energy demands of walking are significant but not large in normal adults who walk at their own speed on the level and we choose our typical walking speed to minimise the energy expenditure. Walking speeds are always slowed down when a patient suffers from neurological and musculoskeletal conditions but because the gait cycle is slowed down in these cases the energy expenditure per unit time may not be increased. However, in stroke for example, the energy demand for accomplishing a specific distance can rise markedly, to more than three times the normal level.
Walking speed can be maintained and energy expenditure reduced by about 50 percent with the use of a wheelchair and the choice of using one is made usually when the patient realises the high level of energy required to get across a certain distance. When the energy effort is more than 300 percent of normal this decision is more likely. - 14130
The process of going through all the stages and getting back onto the same foot again is known as the gait cycle. Both feet are down on the ground for about 10% of the gait cycle, with a single down on the ground for about 40% percent overall. The remainder is made up of the swing part of the cycle as the legs are being brought through to be placed down on the ground again for the next step. As walking gets faster the duration of these phases of the gait cycle reduces and when we start running then there is no double support phase when both legs are on the ground at the same time.
The leg joints follow a specific and repeatable series of actions during the swing and stance phases with stance made up of five sections in the order of initial contact, loading response, mid stance, terminal stance and preswing. Heel strike is the common name given to initial contact but some people do not heel strike at all or transfer weight to the heel later in the phase. Heel strike allows the leg which is about to weight bear to take the weight but not compromise speed, stability or shock protection.
With one leg supporting the bodyweight the other limb is going through the swing phase. The body moves the centre of support over the foot in what is known as mid stance, the initial part of the phase of single leg support. Terminal stance occurs next as the heel of the supporting foot rises from the ground and finishes as the other leg makes heel strike and begins to support weight. Preswing is really a preparation for the swing phase and begins with the last part of the both leg support phase, finishing when the foot is raised to begin swing. Foot clearance above the ground and the forward motion of the leg to engage another step are the function of the swing phases of initial, mid and terminal swing phases.
For gait to be efficient it must incorporate some control over the conservation of energy and the absorption of shocks which can be adversely affected by changes in joint motions and the loss of muscle power. This can cause increases in the joint contact forces and lead to musculoskeletal problems with the loaded structures. Bodyweight loads very fast onto the heel strike leg, with 60 percent being transferred within 20 milliseconds of the start of early stance phase.
The leg joints absorb and control these forces as they act as shock absorbers and dampers. When the leg is placed initially on the ground the forward forces involved tend to make the knee bend so we resist this by making the knee straighter even though this increases the forces through the joints. Loading forces are minimised by eccentric muscle action by the hip adductors and quadriceps.
The energy demands of walking are significant but not large in normal adults who walk at their own speed on the level and we choose our typical walking speed to minimise the energy expenditure. Walking speeds are always slowed down when a patient suffers from neurological and musculoskeletal conditions but because the gait cycle is slowed down in these cases the energy expenditure per unit time may not be increased. However, in stroke for example, the energy demand for accomplishing a specific distance can rise markedly, to more than three times the normal level.
Walking speed can be maintained and energy expenditure reduced by about 50 percent with the use of a wheelchair and the choice of using one is made usually when the patient realises the high level of energy required to get across a certain distance. When the energy effort is more than 300 percent of normal this decision is more likely. - 14130
About the Author:
Jonathan Blood Smyth is a Superintendent Physiotherapist at an NHS hospital in the South-West of the UK. He specialises in musculo-skeletal conditions and looking after joint replacements as well as managing chronic pain. Visit the website he edits if you are looking for physiotherapists in London.
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