Muscular “stiffness” describes the tension stored in myofascial fibers surrounding our muscles or myofascial tensioning. Whenever we take a step, walking or running, there is an interaction of potential and kinetic energy between our feet and the ground, providing the kinetic energy needed for walking. Although this reaction only takes a small fraction of a second to occur, we would not find ourselves able to walk or move efficiently without it.
Before our foot ever touches the ground, our muscles sense the coming impact and tense the muscle and fascial fibers. Once our foot does come in contact with the ground, the energy of the impact is stored as potential energy in the fascial fibers. In this state, the myofascial tensioning of the muscle fibers acts much like a loaded spring, ready to convert its potential energy into kinetic energy.
Finally, as the foot leaves the ground, this energy (stored in the form of muscle and ankle stiffness) is released in the form of kinetic energy used to propel the foot forward. This interaction allows us to have a natural spring in our step, rather than making inefficient mechanical movements and pounding our feet with each step.
The greater the tension of your myofascial fibers are when your foot hits the ground, the more efficient you will be at storing and releasing kinetic energy. Various studies have examined the effects of leg power, stiffness, and strength on the speed of runners, including the studies of Lockie et al. (2011) and Bret et al. (2002).
Specifically, Bret et al. discovered that myofascial tensioning was the single greatest indicator of how fast athletes were able to accelerate in the first and second stages of the 100-meter dash. This study’s results were based on 19 sprinters on the regional and national level, with their performance measured at 30, 60, and 100 meters. While leg strength was directly related to the mean performance of these athletes overall, the fascial tension was the single greatest indicator of acceleration in the first 60 meters.
Similarly, Lockie et al. found that contact time and impulse efficiency were major indicators of overall sprinting performance, with the faster runners testing 11–15% lower in ground contact times . Both of these factors (ground contact time and impulse efficiency) are directly related to myofascial tensioning.
These are only two among many studies in recent years which have shown a strong relationship between muscular tension and running and sprinting performance (Lockie, 2015). Having a strong “spring” is an essential aspect of running or even moving efficiently. So where are these “springs” and how do they work?
Our body’s “springs” are located at the connection of the muscles and the fascial tissue. Intricately woven around all of our muscles and the surrounding tendons and ligaments is what is called a myofascial web. This web surrounds and interconnects with the muscles on three separate levels.
First of all, it forms the sheath of connective tissue surrounding the muscle as a whole, or the epimysium. Secondly, it forms the sheath of connective tissue surrounding the individual bundles of muscle fibers (fascicles), known as the perimysium. Finally, it forms the endomysium, or the sheath surrounding each individual muscle fiber or mycote.
This highly-integrated web of connective tissue is essential to making smooth movements. While all of these layers are intricately involved in the production of muscle tension, studies have shown that especially the perimysium is integral to storing this energy. This is because the perimysium contains more fibroblasts than the other layers of connective tissue. Myofibroblasts are the highly elastic cells which store potential energy—in a sense, these are the “rubber bands” of the muscles.
This storing of energy in the myofascial web is accomplished through something called isometric contractions. Nigg (2001) has studied isometric contractions and developed a new theory wherein muscle “tuning” is seen as a key feature in measuring the efficiency and speed of a runner. In this model, impact forces produce a tactile input which allows the muscle to “tune” itself before its next contact with the ground, which allows the muscle to minimize vibration and reduce the load placed on both joints and tendons . The Exercise-Based Fitness Academy (EBFA) refers to this tuning process as fascial tensioning.
Schleip et al. (2005) have also argued that, far from playing a simple passive role in storing and releasing kinetic energy, the fascia may actually be able to contract and expand in a manner similar to muscles, thus factoring prominently into overall musculoskeletal dynamics. This finding only further supports the importance of training the myofascial tissue for optimal performance, as this tissue affects many aspects of movement and basic locomotion.
You may have heard by now of training focusing on the myofascial web, or as it has also come to be known, “trigger point release” training. As promoted by Lockie (2011), this training aims to reduce ground contact time and improve ground force efficiency by improving the fascial tension and tuning of the myofascial web. However, much of this training advice has not extended beyond simple foam rolling and stretching.
To properly train the myofascial web requires training in rhythmic movements. Such movements are practiced in taiji and the emergent field of gyrotonics, for example. Both exercise systems emphasize continuous, flowing movements and decompression of the joints through moving in natural curving motions. By moving the joints in smooth, circular motions, such exercises optimize the efficiency of the joint movements which stretching and training the myofascial web.
Other exercise methods are also emerging which train the fascia and myofascial web and improve muscle tuning ability. One such method is EBFA’s barefoot training method, a whole-body method which integrates fascial tension zones through a technique called fascial tension stacking. By focusing on four fascial tension zones, the foot, the core, the shoulders, and the hands, the program looks to increase stability as well as muscular resistance, force, and power. These techniques can be incorporated into other workout routines, as well, and may even be tailored to specific body types.
Bret, C., Rahmani, A., Dufour, A.-B., Messonnier, L., & Lacour, J.-R. (2002). Leg strength and stiffness as ability factors in 100 m sprint running. The Journal of Sports Medicine and Physical Fitness, 42(3), 274–281.
Lockie, R. G., Jalilvand, F., Callaghan, S. J., Jeffriess, M. D., & Murphy, A. J. (2015). Interaction Between Leg Muscle Performance and Sprint Acceleration Kinematics. Journal of Human Kinetics, 49, 65–74. http://doi.org/10.1515/hukin-2015-0109
Lockie, R. G., Murphy, A. J., Knight, T. J., & Janse de Jonge, X. A. K. (2011). Factors that differentiate acceleration ability in field sports athletes. Journal of Strength and Conditioning Research / National Strength & Conditioning Association, 25(10), 2704–2714. http://doi.org/10.1519/JSC.0b013e31820d9f17
Nigg, B. M. (2001). The role of impact forces and foot pronation: a new paradigm. Clinical Journal of Sports Medicine: Official Journal of the Canadian Academy of Sports Medicine, 11(1), 2–9.
Schleip, R., Klingler, W., & Lehmann-Horn, F. (2005). Active fascial contractility: Fascia may be able to contract in a smooth muscle-like manner and thereby influence musculoskeletal dynamics. Medical Hypotheses, 65(2), 273–277. http://doi.org/10.1016/j.mehy.2005.03.005