“America is all about speed. Hot, nasty, badass speed.” — Eleanor Roosevelt, 1936

While the above quote from the opening scene of Talladega Nights might not necessarily be historically accurate, it is somewhat indicative of what sports (and the training for them) have become. Football is no longer about three yards and a cloud of dust but rather putting the ball in the hands of the fastest player on the field and letting him run. The time that won gold in the 100-meter dash at the 1992 Olympics in Barcelona would have received seventh place at the 2012 London Olympics. Speed has become the most sought after trait in sports and, as such, it has become the foremost priority in the field of physical preparation.

Over the last few decades, great advances have been made in developing and improving speed in athletes. Between plyometric advances, various weight lifting methods, and technique work, coaches employ hundreds of different means to accomplish the same ends. Much of this work looks closely at developing arm action, hip extension, and knee drive, among others. However, I believe more improvements in speed could be made if we looked lower.

Our feet have been called masterpieces of engineering and it’s a hard claim to dispute. With arches in both the frontal and sagittal plain that absorb anywhere from 1.5 to five times body weight on every stride (O’Leary, et al. 2008) to toe joints that can drastically improve speed and power output, the foot isn't an area to be overlooked in a training regime. Unfortunately, I believe the foot and ankle joint are often treated as afterthoughts at best, and this is hindering many athletes in both speed development and injury prevention. The main purpose of this article is to expose the hidden power available in the four smaller muscles of the lower leg: the flexor hallucis longus, the extensor hallucis longus, the flexor digitorum longus, and the extensor digitorum longus.

Quick Anatomy

Everyone knows about the soleus and the gastrocnemius, as they’re the most prominent in the lower leg. However, it is the much smaller ones that can unlock hidden power potential in athletes. Some play a more synergistic role in just keeping the ankle stable while others play overlooked roles in power absorption and production.

Stabilizers

The tibialis muscles (anterior and posterior) and the peroneus muscles (brevis and longus) serve mostly a postural purpose in maintaining balance and keeping the center of gravity over the more medial mid-foot. They also keep you from shifting around too much while standing. These muscles will be developed effectively just by moving and supporting the body through athletic movements, though their stabilization function will be developed further by barefoot training.

barefoot sprinting anatomy speed 070614

Flexors and Extensors

The big toe is also called the hallux, so as one could probably deduce, the flexor and extensor hallucis longus flex and extend the big toe, respectively. The other toes are called digits, so the flexor and extensor digitorum longus flex and extend the digits, respectively. All the toes connect to the tarsals at the metatarsophalangeal joint (MPJ).

Effects of Metatarsophalangeal Joint Strength

Now, let’s get down to why you should care. Clinical tests around the world have shown that toe flexor muscle (TFM) and metatarsophalangeal joint (MPJ) strengthening improves speed and power outputs on numerous tests. In one such study, a period of strengthening toe flexors showed “significantly greater pre-test to post-test increases in acceleration and velocity in the 36.58 m (40-yard) dash” compared to a control group among college baseball players (Adams, et al. 1988). A seven-week MPJ strengthening regime consisting mostly of maximal voluntary isometric contractions has also been shown to improve broad jump distance as well as overall power output (Goldmann, et al. 2013).

It turns out that athletes who are faster tend to have higher and stronger TFM/MPJ even if they don’t necessarily go out of their way to strengthen them. Researchers at the University of Calgary did a video analysis of 100-meter dash participants at the 2000 Summer Olympics. Predictably, “it was determined that faster male sprinters experienced higher maximal rates of MPJ extension.” Essentially, faster athletes can push off their big toe harder. And just to hammer the point home, those with weaker MPJ plantar flexion have a weaker take off in explosive movements (Stefanyshyn, et al. 1997).

Strengthening the TFM/MPJ

There are many different ways to go about strengthening the lower leg muscles. In most instances, people will either use isometric holds or hook their toes in a Theraband and do various flexion and extension movements. These are all well and good, and I’m sure these methods could lead to a stronger TFM. However, there are two somewhat interlocking considerations to look at here. The first is from Dr. Mel Siff in Supertraining. In the last sentence of chapter three, Siff states, “A generalized approach to understanding human movement on the basis of breaking down all movement into a series of single joint actions fails to take into account that muscle action is task dependent.” Using this, we can realize that it won't be as efficient to train the TFM in a manner that mimics standing up on ones toes rather than sprinting.

This leads to the Principle of Dynamic Correspondence (also from Supertraining), which says that we must look at the best means to strengthen this muscle action so that it carries over best to sport. The criteria and their relation to the TFM/MPJ are as follows:

  • The amplitude and direction of the movement: The toes should go from extreme extension to full flexion, applying horizontal force in the sagittal plane.
  • The accentuated region of force production: The highest demand will be placed on the TFM/MPJ during absorption phases (extreme extension), and the athlete must be able to absorb and produce force from this position.
  • The dynamics of the effort: Strengthening the TFM and MPJ must follow suit with the types of strength required for the desired function. Thus, the speed of movement and type of strength (speed-strength for sprinting) must match the sport.
  • The rate and time of force production: Ground contact times in elite athletes are less than 0.2 seconds during acceleration (Murphy, et al. 2003) and less than 0.1 seconds when maximum velocity is reached. The training must match this speed of execution.
  • The regime of muscular work: As explained earlier, it isn't enough to simply train the muscles in question. They must be trained in the manner that they will be used in the sport. Because muscle action is task dependent, the athlete must train the TFM to work at high speed and improve force absorption/production capabilities.

Track athlete

When analyzing this criteria, it becomes apparent that the most efficient way to allow the TFM and MPJ to reach their force output potential is to engage them in running and jumping activities (because very few sports involve slow, controlled calf raises on to an athlete's tiptoes). This is where barefoot training comes into play. I know I’m not the first person to preach using barefoot training with athletes. Just some of the documented benefits and notes are as follows:

  • Decreased patellofemoral stress (Bonacci, et al. 2013)
  • Lower incidence of heel strike running technique and increased force production from forefoot and hallux (Mullen and Toby 2013)
  • Increased activation of the lower leg muscles (Shih, et al. 2013)
  • Improved running economy (Warne and Warrington 2012)
  • Improved peak force and increased height on vertical jump and Bosco tests when compared with tennis shoes or minimalist shoes (LaPorta, et al. 2013)
  • Improved agility and single leg stability compared to shod training (Venter, et al. 2011)

With all these benefits, barefoot training should be a no-brainer. However, I believe there is a link that's missing. Most studies that I’ve reviewed never get the test subjects up to a full sprint let alone use trained athletes in the study. Often, the tests and training are done in a more extensive manner relating more to distance running application. While this will definitely improve running economy as well as soleus and gastrocnemius activity, the TFM/MPJ will never be exposed to high speed and high intensity loading inherent in sprinting. Yet when athletes do intensive sprints, they strap on their cleats or spikes and cram their toes in, which has been shown to severely limit MPJ flexion ability and speed of flexion (Toon, et al. 2009). My grand argument out of all this is to perform linear sprints entirely barefoot.

This revelation hit me while performing sprints one day on an indoor turf field. I figured that I would try doing full sprints and accelerations without shoes or socks of any sort. I expected to slip, especially when coming out of a 40-yard dash stance due to the increased horizontal force production (as opposed to a position start or a lean-fall). Instead, my digits instinctively gripped into the turf and I was able to work full extension off the big toe of my drive leg in a way that I never had been able to in cleats. I decided to do all my sprints for a four-week cycle in bare feet to see if my force application improved. After a month, my vertical jump improved an inch and a half and my 40-yard dash went down 0.08 seconds without ever getting above 110 yards of sprint volume on a given day.

Why It Works

In retrospect, the simplicity of barefoot sprinting seems too easy to produce such good results. But when looking at what is truly going on in the foot and lower leg, it only makes sense. The gripping action of the toes serves to strengthen the TFM in the most directly applicable manner, which leads to better carryover to actual sprinting performance. The big toe becomes a bigger part of the kinetic chain due to the increased mobility and becomes a larger contributor in the first portion of the landing phase (amortization) and the final part of the body on the ground during push off. The TFM and MPJ were not only strengthened effectively, but, perhaps more importantly, they were strengthened at the required speed.

While one could run faster in spikes or cleats, the total affect on the body is lessened due to the hindrance on the MPJ (Smith 2012). When doing sprints in cleats or even track spikes, the MPJ is severely limited in mobility and protected from absorbing the energy it should be learning to absorb. In addition, the cleats or track spikes slow down whatever muscle action does occur for the TFM (Toon 2008). This limitation not only holds back power capabilities, but the decreased mobility (especially in extension) could contribute to turf toe injuries down the road (Rodeo et al. 1990).

Speed blur

Recommendations

Through my personal experience and looking at research, there are more effective means of implementing barefoot training than others. Simply changing all your teams’ workouts to barefoot will lead to a large amount of soreness and pain. Proper progression must be followed with this as with any other training means.

I’ve found that the best way to implement barefoot training (with minimalist footwear in the weight room/court for hygienic and gripping purposes) is to look at the training means in terms of foot contacts, with the exception of shock method jumps. My standard progression for myself and the athletes I’ve worked with has been as follows, with progression only occurring when there isn't any lower leg soreness/fatigue:

  • Weight lifting workouts: Obviously, these have very few foot contacts, but the increased mobility and stabilization requirements (especially on unilateral lifts) offer a good starting stimulus.
  • Warm-ups: Increase the number of foot contacts, though at a low intensity. This also helps with mobility.
  • Shorter sprints/lower intensity plyometrics: While the intensity is high, the number of contacts and total amount of work performed are lower than the following phases.
  • All intensive sprints: This is the same story as with the shorter sprints, but by now, the TFM and MPJ have adapted to more intense force production requirements.
  • Extensive runs: This may seem counterintuitive, but the soreness encountered from the comparatively massive amount of foot contacts has always led to the most lower leg soreness encountered.
  • High intensity plyometrics: This is more due to the desire to have the proper landing/takeoff mechanics in the name of safety. There won't be very much soreness encountered after this phase.

To sum up, we must allow all our muscles to go through their full ranges of motion to realize their peak force production potential as well as reduce the incidence of injuries. This has been well understood for all the muscles above the knee, yet too often we allow our athletes to cram their toes into shoes that compensate deficiencies for them. The foot is almost always capable of self-correcting postural deficiencies as well as explosive jumping or sprinting technique. By having athletes perform intensive sprints (especially accelerations) completely barefoot, we allow often forgotten muscles to unleash untapped power and speed on the field.

References

  • Bonacci J, Vicenzino B, Spratford W, Collins P (2013) Take your shoes off to reduce patellofemoral joint stress during running. British Journal of Sports Medicine.
  • Adams TB, Bangerter BL, Roundy ES (1988) Effect of Toe and Wrist/Finger Flexor Strength Training. The Journal of Strength & Conditioning Research. Retrieved July 20, 2013. At: http://journals.lww.com/nsca-jscr/Fulltext/1988/05000/Effect_of_Toe_and_Wrist_Finger_Flexor_Strength.4.aspx.
  • Goldmann JP, Sanno M, Willwacher S, Heinrich K, Brüggemann GP (2013) The potential of toe flexor muscles to enhance performance. Journal of Sports Sciences 31(4):424–33.
  • LaPorta JW, Brown LE, Coburn JW, Galpin AJ, Tufano JJ, Cazas VL, Tan JG (2013) Effects of Different Footwear on Vertical Jump and Landing Parameters. Journal of Strength and Conditioning Research 27(3):733–37.
  • Mullen S, Toby EB (2013) Adolescent runners: the effect of training shoes on running kinematics. Journal of Pediatric Orthopedics 33(4):453–57.
  • Murphy AJ, Lockie RG, Coutts AJ (2003) Kinematic determinants of early acceleration in field sport athletes. Journal of Sports Science and Medicine 2:144–50.
  • O’Leary K, Anderson Vorpahl K, Heiderscheit B (2008) Effect of Cushioned Insoles on Impact Forces During Running. Journal of the American Podiatric Medical Association 98(1):36–41.
  • Rodeo SA, O’Brien S, Warren RF, Barnes R, Wickiewicz TL, Dillingham MF (1990) Turf-toe: An analysis of metatarsophalangeal joint sprains in professional football players. The American Journal of Sports Medicine 18(3):280–85.
  • Shih Y, Lin KL, Shiang TY (2013) Is the foot striking pattern more important than barefoot or shod conditions in running? Gait & Posture.
  • Smith G (2012) Biomechanics of foot function in relation to sports performance (PhD) Liverpool John Moores University. Retrieved from: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.570722.
  • Stefanyshyn DJ, Nigg BM (1997) Mechanical energy contribution of the metatarsophalangeal joint to running and sprinting. Journal of Biomechanics 30(11):1081–85.
  • Toon D (2008) Design and analysis of sprint footwear to investigate the effects of longitudinal bending stiffness on sprinting performance (PhD) Loughborough University. Retrieved from: https://dspace.lboro.ac.uk/2134/12125.
  • Toon D, Williams B, Hopkinson N, Caine M (2009) A comparison of barefoot and sprint spike conditions in sprinting. Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 223(2):77–87.
  • Venter R, De Villiers JE (2011) The effect of barefoot training on speed, agility, power and balance in netball players (Thesis) Stellenbosch: Stellenbosch University. Retrieved from: http://scholar.sun.ac.za/handle/10019.1/18021.
  • Warne JP, Warrington GD (2012) Four-week habituation to simulated barefoot running improves running economy when compared with shod running. Scandinavian Journal of Medicine & Science in Sports.