Editorial note: The author would like to thank Mark Roozen and Brandon Stone for their contributions to this article.
Barefoot training has recently experienced a surge in popularity and has been shown to improve foot mobility, stability, and activity. Additionally, it has been linked to increased lower limb muscle firing and greater muscle activation patterns through the kinetic chain. In some cases, there is evidence that barefoot training can even decrease lower extremity, hip and low back pain. Read on to find out more about this controversial but fascinating new training modality.
There are roughly 206 bones in the human body and exactly one-quarter of these, 52 to be exact, reside in the feet. The anatomy of the foot is designed to allow transfer (during linear ambulation) of the body weight from the heel toward the lateral side of the mid-foot. Once the weight is transferred to the lateral side, it moves through the ball of the foot and toes to propel the entire body forward. An easy way to notice this phenomena is to look at a footprint in the sand.
The design of the foot is somewhat similar to that of the hand. There are three major divisions: The tarsals, the metatarsals, and the phalanges. These three divisions of the foot interact with the talus to allow for movement of the foot. The talocrural joint (the ankle joint), is comprised of the talus, the tibia, and the fibula. These three bones allow the foot to plantarflex, dorsiflex as well as invert and evert on multiple axes. In fact, the ankle may be viewed as a modified ball and socket joint with the primary function being mobility. The intertarsal joint (the back of the foot) is surrounded by tendons and muscles that act to contract and relax to create movement and to aid in the transfer of body weight. The tarsometatarsal joint joins the tarsal and metatarsals together. Again, this joint is surrounded by tendons and ligaments to enable the foot to move in different planes.
A simple model of the joint between the leg and the rear-foot is that of two hinges each with one degree of freedom. The superior hinge at the talocrural joint provides most of the sagittal plane motion due to its mediolateral orientation. Motion in the transverse and coronal planes (inversion/eversion) is largely taken up by the subtalar joint. It could be expected, from the orientation of the joint, that rearfoot motion in the coronal plane (inversion/eversion) would be tightly coupled to motion in the transverse plane (adduction/abduction) to create movement. These three joints then push the weight through the phalanges.
Although the intertarsal and tarsometatarsal joints have limited movement, the surrounding anatomy keeps the joint in place and allows for movement. It could be compared to a hunting bow. The bow (the tarsometatarsal joint in the case of the foot), remains fairly limited and stable but the string (the tendons and muscles) acts around the bow to create movement of the entire apparatus. This example illustrates how the foot needs significant movement to allow for optimal weight transfer, locomotion, and to aid in the windlass effect.
The term windlass refers to an instrument that accounts for a load by pulling on a specified line. In this case, the instrument is the foot, the plantar fascia is the line of action, and the load applied is your body. With all the bones, muscles, tendons, and ligaments in the foot, a superfluous harmony must be present in order for the windlass effect to successfully deliver the force required during locomotion. The composition of these structures must have the ability to summate into a lever that must be rigid enough to propel the body forward and create flight. Flight, in this case, is the flight phase observed during running.
The initiation of the windlass effect occurs during the mid-stance of the stride—essentially when the foot initiates contact with the ground. All the structures of the foot form the aforementioned lever essential to providing the force producing line through the plantar fascia and then finishing its task through push-off at the tarsometatarsal joints.
The somatosensory system, a major activator in all muscle and tendon action, is best described as the system that provides orientation information of body parts to one another and to the supporting surface, to maintain postural equilibrium. In other words, it controls how we move our center of gravity and body parts in relation to our environment. This includes cells or organs called proprioceptors and tactile sensors. Proprioceptors are receptors spread throughout the muscles, ligaments, joints, and connective tissues that tell us not only where our body parts are in relation to each other and the outside world, but also how fast and where they may be moving. The tactile organs detect such things as touch, pressure, and vibration and also influence balance and movement.
Of particular importance are those of the plantar surface of the feet. They have been shown to supply the central nervous system (CNS) with information regarding weight distribution upon each foot as well as between the feet. Not only are they an important source of input on static position and body sway, they play a “significant role during dynamic and functional movements as well,” according to Riemann and Guskiewicz. These cutaneous receptors provide information that blend with the receptors of muscles and joints further overlapping the system of neurological input that guides movement and balance.
Through proprioceptive activity, these tissues are cued to respond (through length and tension properties) and our muscles are allowed to activate based on the information given. Proprioceptors are activated upon the initiation of movement of the body. Once activation occurs, the proprioceptors engage the foot and allow the foot to complete weight transfer.
The Problem with Shoes
This is where athletes often run into problems. The latest and best cross trainers, athletic shoes, and various forms of specialized shoes are all made to protect the foot and ankle from injury and maintain a neutral foot and ankle complex during activity. Additionally, ankle wraps, orthotics insoles, as well as other shoe inserts and ankle supports are designed to provide foot stability, prevent injury and ultimately assist in foot and ankle functionality. The idea is that the external device (i.e. ankle wrap, insole, etc.) allows for limited range of movement so injury is either prevented or limited. This, however, is the equivalent to putting a Band-Aid on an open wound. It may mask the wound, but it doesn’t heal it. In an effort to protect and assist through wrapping, shimming, or restricting the foot and ankle, we may actually inhibit normal proprioception, muscle and tendon action, and overall gait properties.
If you look at commonalities in current shoe design, the trend is to provide support and stabilization throughout the foot depending on the demand of the shoe. Additionally, extra padding is popular and some shoes have been designed to help keep the foot “in place.” While this rationale may seem beneficial and mechanically advantageous, it can prevent the foot from moving in a natural pattern. So the question becomes, how does the coach or trainer address this? Footwear, obviously, cannot be completely omitted from training or competition as it does serve to protect our feet from positive and recognized variables. Typically, however, we are in shoes all day, every day, so the solution may be to remove shoes for a portion of training.
Create an Agenda
Just as a progression schedule is essential with any good strength and conditioning program, so to is an agenda invaluable when introducing barefoot training to a client. Further, those who engage in a barefoot training program need to understand the benefits of barefoot training, what to expect from this training, and how to institute this training modality.
Presence of Pain
When barefoot training is first introduced, foot and/or calf soreness is common. Be aware, however, of sharp or deep-rooted pain and residual soreness; these types of discomfort should not be present during training, just as in other training modalities. There should also be a distinction between pain and injury. If pain is present, take the proper precautions to assess the individual and seek professional help to determine the cause and address the problem. Until the cause has been pinpointed and corrected, the individual should cease barefoot training.
There are several ways that a barefoot training program can be added to a traditional strength and conditioning session. First, it is important to assess the type of surface to train on. Ideal surfaces include artificial turf, traditional basketball courts, and rubberized gym floors since these surfaces allow the athlete to have a firm yet forgiving surface beneath them.
Implementing the Training
A simple way to introduce barefoot training into strength and conditioning program is to use it as part of a standard warm up. The use of tennis, golf, lacrosse or similar balls is often used at the onset of training on the plantar surface of the foot. The athlete rolls the bare foot on the ball, usually in a seated position, with some light pressure for a minute or so on each foot. This can be repeated for the desire number of repetitions or for a set period of time. This initial activity will stimulate blood flow and begin to get the tissues of the plantar surface activated and prepare the foot for higher levels of activity.
After the initial introduction period, the next progression may be to start the warm up with low level activities such as walking knee hugs, shin grabs, spider man walks, inch worms and other walking patterns. For beginners, running or even light plyometrics should be avoided. Just as a beginner wouldn’t start off a plyometric program doing high level, intense type jumping, bounding and loaded maneuvers, the same caution is warranted here. Table 1 illustrates eight selected exercises that could be used in conjunction with a barefoot warm-up. Table 2 gives an idea of simple, low level plyometrics that may be suitable for barefoot training and table 3 provides a list of basic speed ladder drills that can be incorporated into the program.
|Figure 1 Ladder Drill Patterns
After the athlete has initially adapted to the barefoot training, adding ladder drills, mobility drills, and even low level plyometric skips and pogo hops may be introduced. All of these will enable the athletes to achieve optimal benefits from being barefoot, while also adjusting to increased balance and stability. After this portion of the program has been inserted and adapted to, then add body weight movements, trunk and “core” exercises, and movements in different foot positions (wide and narrow stances, staggered and one foot positions) that allow the entire kinetic chain to increase performance can be incorporate to progress to different levels.
While barefoot training isn't the only effective method for foot and ankle training, it can fit into a well-structured program if used properly. Appropriately integrated and progressed into training it can be a beneficial tool to increase performance, reduce injuries, and increase overall wellness and safety with clients or athletes. Figure 1 Ladder Drill PatternsWhile barefoot training isn't the only effective method for foot and ankle training, it can fit into a well-structured program if used properly. Appropriately integrated and progressed into training, it can be a good tool to increase performance, reduce injuries, and increase overall wellness and safety with clients or athletes.
- Denton, J.D. The Windlass Effect Protecting the Plantar Fascia’s Propulsion Power. Running Times. September. 2003.
- Flores, A. Objective Measures of Standing Balance. Neurology Report-Am Phys Ther Assoc 16: 17-21, 1992.
- Nasher, L. Practical Biomechanics and Physiology of Balance. In Handbook of Balance Function and Testing. Jacobsen, G., Newman, C., Kartush, J. (Eds.), 261-79. St. Louis: Mosby Year Book, 1993.
- Riemann, B., Guskiewicz, K.M. Contribution of the Peripheral Somatosensory System to Balance and Postural Equilibrium. In: Proprioception and Neuromuscular Control in Joint Stability. Lephart, S., Fu, F., (Eds.) p.39-40. Champaign, IL: Human Kinetics, 2000.