The simplified version of the ‘Preferred Motion Pathway‘ model is that each individual has a preferred pathway for a given task (and that will vary from person to person). The model considers that if you function within that pathway, then you are more efficient and have a less risk for injury. If you function outside that preferred pathway, then you are inefficient and at greater risk for injury. The aim of an intervention to manage an injury to to move the individual back into their preferred pathway for the movement that is associated with the injury. A number of experiments have been published based on this model and a number of experimental results have been interpreted in the context of this model. The most recent one is this study looking at preferred running strike patterns and the effect of that on soft tissues vibrations:
The effects of preferred and non-preferred running strike patterns on tissue vibration properties
Hendrik Enders Vinzenz von Tscharner, Benno M. Nigg
Journal of Science and Medicine in Sport; Available online 1 May 2013
To characterize soft tissue vibrations during running with a preferred and a non-preferred strike pattern in shoes and barefoot.
Participants ran at 3.5 m s−1 on a treadmill in shoes and barefoot using a rearfoot and a forefoot strike for each footwear condition. The preferred strike patterns for the subjects were a rearfoot strike and a forefoot strike for shod and barefoot running, respectively. Vibrations were recorded with an accelerometer overlying the belly of the medial gastrocnemius. Thirteen non-linearly scaled wavelets were used for the analysis. Damping was calculated as the overall decay of power in the acceleration signal post ground contact. A higher damping coefficient indicates higher damping capacities of the soft tissue.
The shod rearfoot strike showed a 93% lower damping coefficient than the shod forefoot strike (p < 0.001). A lower damping coefficient indicates less damping of the vibrations. The barefoot forefoot strike showed a trend toward a lower damping coefficient compared to a barefoot rearfoot strike. Running barefoot with a forefoot strike resulted in a significantly lower damping coefficient than a forefoot strike when wearing shoes (p < 0.001). The shod rearfoot strike showed lower damping compared to a barefoot rearfoot strike (p < 0.001). While rearfoot striking showed lower vibration frequencies in shod and barefoot running, it did not consistently result in lower damping coefficients.
This study showed that the use of a preferred movement resulted in lower damping coefficients of running related soft tissue vibrations.
This study is based on the premise that impact with the ground sets up a vibration in the soft tissues similar to a shock wave that travels up the body. Most of these vibrations are normally dampened by a number of mechanisms to minimize the detrimental effects (ie injury) of the vibrations. It has been suggested that the more vibrations there are, the harder the muscles have to work to dampen it. If they have to work harder, then this impacts on efficiency and increases the loads for injury risk. The aim of the above study was to investigate the damping effect in shod and barefoot running on these soft tissue vibrations and if the foot strike pattern was a preferred pattern or not.
What did they find:
- they showed that when the runners in the study used their preferred strike pattern during both shod and barefoot running, that this resulted in lower damping coefficients (a good thing). This is considered a result of optimizing a particular movement pattern (ie they were in their ‘preferred motion pathway’).
- There was no difference in that ‘shock wave’ and its damping between barefoot and shod conditions.
Practical Implications (as described by the authors):
- there is no conclusive advantage of barefoot or shod running with respect to tissue vibration properties.
- tissue vibration is primarily governed by the preferred running style of an individual.
- the discussion about shod and barefoot running should consider a runners individual preference more strongly.
What does this all mean?
It means that there is no one best way to run for all. It is individual and subject specific. Everyone has their own preferred pathway for any given task ….. now we only need better tools to determine that for each individual.
As always, I go where the evidence takes me.
Enders H, von Tscharner V, & Nigg BM (2013). The effects of preferred and non-preferred running strike patterns on tissue vibration properties. Journal of science and medicine in sport / Sports Medicine Australia PMID: 23642961