Tuesday, 23 March 2021

Running Elastically - the elastic recoil properties of our fascia

Running elastically allows us to propel ourselves forward using less energy and hence we can run faster and for longer.

Running is a hop, flight and hop movement and so when we are running we are stepping over something and so at some point we are in the air floating (both feet off the ground), whereas when we are walking one foot is always in contact with the ground. To achieve this floating we create the right amount of tension and compression for fascia’s elastic recoil to bounce us forward in the air and this is running “elastically”.

Our fascia is defined as “a sheath, a sheet or any number of other dissectible aggregations of connective tissue that form beneath the skin to attach, enclose and separate muscles and other internal organs.” (Stecco 2015).  Or as I like to call it - our big yellow 3D tensile onesie found under the skin. Fascia influences and aids all our body’s movements, through tension and compression throughout the body, rather than singling out individual muscle contractions for individual actions.

Fascia stores energy

Fascia has the ability to temporarily store energy and return it quickly, giving us the ability to bounce. We see this in cyclic movements, such as running and cycling, and it is the same as explosive rhythmic running in animals such i.e. gazelles or cheetahs. Running elastically uses less energy, and less muscular power, and so importantly it helps prevent typical overtraining injuries.

So how do we “run elastically”? For ease of understanding I am going to focus on one key point and this is the importance of the positioning and flexibility of the ankle and the foot, or more precisely the arch of the foot and the Achilles tendon, for the foot strike phase.

Ability of the foot arch and Achilles to recoil and propel

In order to achieve elastic recoil from the arch and the Achilles the ankle needs to be dorsiflexed (which means bringing your toes slightly towards your nose) for landing. In dorsiflexion the subtalar joint (the joint between the ankle and the start of the foot) locks therefore upon foot strike there is less stress through the body. The impact force from this foot strike stretches your Achilles tendon and all the fascia of the arch of the foot (which includes the lower leg and toe tendons which run and insert on the sole of the foot) plus the force is momentarily stored as elastic energy.

Upon landing the Achilles reaches its maximum safe stretch and your stretch reflex causes your calf muscles to contract to start the propulsive take off stage of running. So for take off the foot rocks from heel to toes and the ankle starts to plantarflex (the ball of the foot points into the ground) and as this muscular contraction happens simultaneously the arch of the foot releases its stored elastic energy, which has be shown to create 17% (1) of forward force, and the Achilles tendon then releases its stored energy which has been shown to create 25% (1) of forward force, and we are propelled forward to float through the air!

This is the fascia’s elastic recoil creating the push and bounce forward adding to the force generated by our muscles. The stronger the release of this recoil the less time the foot is on the ground and the body is moving freely forward in the air! This is the free energy created by the impact force from each foot strike.

It is important to remember that fascia and tendons are the major recoil force and the stiffer you are the more energy it takes to stretch them so keeping all our soft tissues supple and flexible eases our movement and the amount of energy it takes to move!!

Please note, this article is intended as brief explanation about the importance of the foot strike in running sports and healthy soft tissues and how it can help us become more effective and efficient runners, it is not a set of running instructions. It is something for you to think about.

The next thing of course is to keep this in mind while training! Please let me know if you have any questions or I can support your training and treat your Soft Tissues
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Author - Nicky Holbrook, Sports Massage and Remedial Soft Tissue Therapist plus Myofascial Release, Lindfield, www.nickysportsmassage.co.uk

(1) Dr Wilbour Kelsick Presentation, 26th June 2017, British Fascia Symposium, Worcester.