Pacerpole

Our Walking Stride.
The arm and leg stride Length - and Rate. 2010

Written in response to a request on a Walking Forum for those interested in a more technical understanding of the arm's stride leverage - when its "function" is to lever the trunk upwards and forwards to improve posture and walking ....rather than focusing on increasing the arm's swing action in front of the trunk as a means of exercise.

The arms and legs are levers - able to increase their length and rate as they stride-out.
The leg can increase it's length by automatically moving further onto the toes at the point of thrust. There's also the proportionate increase in trunk/pelvic rotation which equates to a lengthening within the stride. The actual increase in the range of movement (rom) at the hip has a proportionate reaction at the knee joint rom to lift the foot/lower-leg which shortens the 'pendulum', raising the limb's weight i.e. the limb's centre of gravity, nearer to the pivot point - and so proportionately increasing its natural rate. The extent of reaction at each joint is inter-related/automatic (as opposed to being considered i.e. we don't knowingly do the calculations as a brain exercise...) as we flow along. If we force an action - so that there is an increase in activity at one joint which is disproportionate to the rest, then the total limb action ceases to be optimum and becomes more tiring.

By understanding how the arm's stride leverage can be integrated naturally to contribute fully without wasting effort when walking, means the body can move more efficiently from place to place i.e it maximises the whole of the body's performance 'potential' - so as well as improving the vertical body posture for better breathing, the leverage can be directed into the balanced longer strides/quicker rate of brisker walking etc.
When the arm includes the extra segment/shaft so it can make ground contact - then the arm's action now ceases to be the familiar pendular one, swinging to and fro. When in its 'ground-contact-phase', the arm's action transforms into a 'metromome' pivoting over the shaft tip on the ground - similar to the leg/trunk pivoting over the foot - which is why the arm's stride action during this phase, has the potential to supplement that of the legs underneath, to support and lift the trunk upwards and move it forwards. During the pendular swing when the arm/shaft tip is off the ground, the arm action is preparing for the next step i.e. the geometry of the arm joints arrange themselves/their limb segments for this walking "function" during their 'swing-phase' off the ground .....so that when the tip touches the ground they are already forming the right 'shape' to lever the trunk upwards and forwards again.
Where the shaft tip pivot point is placed as it touches down in relation to the trunk eg on the ground under the shoulder, will also determine how effective the arm's stride can be in fulfilling its walking function and improving posture.

The legs dictate the walking speed - so as their rate and length of stride increases - then trying to increase the arm's speed by increasing the pendular swing phase of a more straighter arm-stride action in front of the trunk will result in a more forced action. With this straighter arm stride, then the resulting geometry of the arm joints when they touch-down for the 'ground contact' phase means that they are unable to lever the trunk upwards effectively but disproportionately rotate it too much - whilst their potential to instigate the stride to lift and move the trunk as per the leg action, for a naturally brisker speed is compromised.
For the arm's stride - to fulfil its walking "function" of keeping the trunk vertical as it levers it upwards and forwards - requires proportionately little shoulder movement to bring the pole forward for the next step. Instead the action should focus on the muscles working as fixators to 'fix' the rather mobile shoulder girdle into providing a firm base for Triceps/elbow extensors to thrust from ....so that the thrust can be more effective to increase personal 'briskness' and better posture.
 
As soon as the elbow flexes after the push-off, then this lower arm swing action can bring the shaft tip forward for its next placement on the ground under the shoulder ....without needing the shoulder to sweep the arm forwards. The increase in the arm's stride length takes place in a combination of ways - such as by pushing-off further along the thumb shelf of the contoured Pacerpole handle, which also controls the forearm rotation (keeping the arm segments aligned to optimise their leverage potential which would otherwise be wasted i.e. underperformance). In addition, the slight increase in the range-of-movement of the upper arm's arc of movement behind the trunk, moves the elbow a little further back - and has the effect of increasing the stride length, with the shaft tip placement angled further behind the heel (instead of opposite the foot's heel or instep). The natural/proportionate trunk rotation - as the trunk moves around its vertical axis - will also increase the strides length (as per the proportionate pelvic/trunk rotation below) ...without the need to force the shoulder rom disproportionately in order to increase the arm's stride length.

Walking is a whole body, dynamic action. Maximising the arm's walking stride potential will improve the walking performance of the whole body - whatever the fitness level of the user. Using Pacerpoles provides for this - and integral is the understanding of how to get the best out of yourself and your arm's stride, whilst reinforcing better body posture as you walk.