This blog post is based on the article, ‘Walking with mechanical advantage’ (The Alexander Journal no.28) by Lawrence Jones, to whom I’m very grateful.
Introduction
Walking well and without injury involves minimizing both energy expenditure and impact forces. Unfortunately, social and cultural forces, as well as individual habits, interfere adversely with the way most people walk. For example, wearing shoes usually prevents the toes of the back foot bending adequately as it lifts off. The dorsiflexion (bending) of the big toe reduces from a healthy 60 degrees when barefoot to 45 degrees with soft sole shoes, and even further to 25 degrees with stiff shoes. This has ramifications, as explained later.
There is one essential caveat to the ten principles I outline below. Walking involves our whole body, and so the individual principles need to be understood within the context of finding appropriate muscle tone throughout our whole musculoskeletal system. You could call this ‘Principle 0’, and it is the groundwork provided by lessons in the Alexander Technique.
PRINCIPLE 1: allow the legs to remain more or less bent at all times
The legs are never perfectly straight in efficient walking. This is because, when walking, we need movement in the torso, pelvis, legs and feet to absorb the shock of heel strike impact.
If we did not bend at the joints of the legs and feet, we would end up with a ‘Frankenstein’ walk, or something resembling a pair of compasses trying to walk (why not give it a try!). The kind of walk that only allows movement at the hip joints results in the body dropping around 10cm with each step. This can be compared to efficient walking which involves exquisitely timed bends at appropriate joints, and which results in a body drop of only around 4cm with each step.
Most people try to lengthen their stride by reaching further forward and straightening the front leg. If you want to increase your speed, instead increase the swing angle of the rear leg and increase toe dorsiflexion (see below).
PRINCIPLE 2: allow the back leg to swing forward
After the first three steps from standing, we do not need to drive ourselves forward during walking. Newton’s law of conservation of momentum keeps us going forward at an almost steady pace. We should therefore be aware of the pendular swinging motion of the legs at the hip joints, rather than excessive effort in the hip flexors.
A surprising video of a ‘passive walking robot’ gives you an idea of what momentum alone can achieve in walking.
PRINCIPLE 3: from a static position, allow the head and body unit to tilt forward before the leg moves
Getting up to walking speed from a static position requires the generation of an overall forward force during the first three steps. This is not achieved with leg forces, but by tilting the whole head and body unit forward slightly, before allowing the leg to swing underneath.
The movement is assisted by the gluteus maximus muscles working at low intensity.
PRINCIPLE 4: allow the knee of the swinging leg to bend sufficiently
The tibialis anterior muscle, which is used to raise or flex the foot, is for most people continuously active as the leg swings forward. This is because most people raise the foot to avoid contact with the ground.
Instead, we can allow the knee of the swinging leg to bend sufficiently so that a released ankle and foot clear the ground. This has several advantages:-
- the foot can hang free instead of being shortened by tension at the ankle;
- the more the leg is bent, the more its natural frequency is increased towards the actual frequency of the swing;
- the forces required to accelerate and decelerate the leg are reduced with a more bent leg.
PRINCIPLE 5: allow the pelvis to rotate
The rear leg pushes its hip forwards, and the front leg pushes its hip backwards, creating a torsion (twist) on the pelvis. This means that the left and right sides of the pelvis move alternately back and forth. This pelvis rotation:
- increases stride length;
- helps shock absorption by reducing the body drop distance;
- assists in the forward swing of the free leg.
PRINCIPLE 6: allow the shoulders to swing back and forth
The rotation of the pelvis is absorbed by the cross-pattern action of the pelvis against the shoulders, helped by the arms swinging. In other words, a forward rotation at the right hip is absorbed by a forward rotation at the left shoulder, and vice versa. If we prevent this cross-pattern action by fixing our arms at our sides, the energy requirement for walking increases by about 7%.
We should remember it is the shoulders that cause the arms to swing and not the other way round. The natural frequency of the arm swing is very close to an efficient walking step frequency, and therefore the arms can be left alone to swing without effort. As an aside, if you bend your arms, the natural frequency of the arm swing increases – which is one reason we run with bent arms.
PRINCIPLE 7: allow the pelvis to sway from side-to-side
For stability, the pelvis needs to move from side-to-side to keep the body’s centre of gravity over the standing leg. It is most efficient to move the centre of gravity over the foot by allowing the pelvis to sway to that side, while keeping the head rather free of side-to-side movement. Keeping the sway in the pelvis rather than the head helps maintain visual integrity. To assist, a narrow step width will avoid the need for excessive side sway (in other words, the opposite to the ‘sea-legs’ of a sailor’s widened gait).
Out of interest, fashion models wearing high heels on the catwalk will employ an exaggerated side-to-side sway to help absorb impact forces. This is because their feet, being so restricted, cannot provide the usual assistance.
PRINCIPLE 8: allow the sides of the pelvis to tilt up and down
In walking, the standing hip rises and then descends during the leg swing. By allowing the pelvis to tilt up and down, the innate flexibility of the sacro-iliac joint is better able to participate in shock absorption.
Many people keep their pelvis rather fixed and level during walking by preventing the landing hip joint rise which would otherwise occur naturally during the heel strike.
PRINCIPLE 9: allow the foot to roll from the heel along the outside of the sole and across to the big toe
The feet are the most important actors in shock-absorption and creating a ‘sine-wave’ up-and-down trajectory of the body.
As soon as the weight lands on the heel, the act of rolling the foot begins. The centre of pressure progresses smoothly from the heel along the outside of the foot and then across to the ball of the foot and toes. The final push off is from the big toe which, in a healthy movement, will dorsiflect up to 60 degrees.
PRINCIPLE 10: allow full dorsiflexion of the toes, particularly the big toe
As mentioned above, the wearing of normal shoes prevents the full dorsiflexion of the toes. In particular, a healthy big toe should be able to dorsiflect up to 60 degrees.
Allowing full dorsiflexion of the toes as the back foot lifts off the ground creates a stronger and stiffer foot. This is because dorsiflexion of the toes tightens the plantar fascia ligament along the bottom of the foot through a mechanism known as the ‘windlass action’.
Healthy toe dorsiflexion also assists with the forward swing of the back leg and with the upward force required to raise the body.
