By: Justin Price, MA
The foot and ankle complex is extremely important to the overall function of the human body. Since it is the only structure that interacts with the ground while in an upright position, the foot and ankle complex is directly responsible for the distribution of weight and pressure throughout the body when the forces of kinetic energy, gravity and the ground collide. Therefore, it is imperative that the foot and ankle complex is fully functional and doing its job correctly to ensure that the force of gravity is properly dissipated throughout the rest of the body.
Common Problems in the Foot and Ankle Complex
One of the main postural deviations that cause pain and injury in the foot and ankle area (and resultant compensations in the rest of the body) is overpronation.
Pronation is a normal function that occurs when the foot rolls inward toward the midline of the body. This movement causes the heel to collapse inward and the medial arch of the foot to elongate and flatten. Overpronation, however, is when the foot collapses too far inward for normal function. Consequently, this directly affects the ability of the foot to perform and can disrupt proper functioning through the entire body.
In addition to problems overpronation causes in the feet, it can also create issues in the calf muscles and lower legs. The calf muscles, which attach to the heel via the Achilles tendon, can become twisted and irritated as a result of the heel rolling excessively toward the midline of the body. Over time this can lead to inflexibility of the calf muscles and the Achilles tendon, which will likely lead to another common problem in the foot and ankle complex, the inability to dorsiflex. As such, overpronation is intrinsically linked to the inability to dorsiflex.
Pronation is Good, Overpronation is Not
The foot and ankle complex needs to pronate to make the muscles of the hips and legs work correctly. Many muscles that originate from the pelvis attach to both the upper and lower leg. For example, the gluteus maximus and tensor fascia latae (TFL) attach to the outside of the lower leg via the iliotibial band, while the abductors attach to the outside of the femur. When the foot pronates, the whole leg rotates inward toward the center line of the body. This inward rotation pulls the attachment of the glutes, TFL and abductors away from the origin of these muscles up on the pelvis which creates tension. Similarly, the muscles of the lower leg such as the peroneals, tibialis anterior and tibialis posterior originate on the lower leg and attach to the underside of the foot. When the foot flattens out, as it does in pronation, this pulls the insertion of these muscles away from their origin on the tibia. This action also creates tension in the muscles.
To better understand how the muscles and tissue structures in the feet, ankles, legs and hips are adversely affected by overpronation, imagine a person on the end of a bungee cord jumping off a bridge. If the bungee cord gets the right amount of tension on it as the person nears the ground, then he/she will be saved from smashing into the earth. However, if the bungee cord does not pull tight because it is twisted or has no elasticity, then the person will impact the ground with dire consequences. The muscles, tendons, ligaments, and fascia of the legs and feet are the body's bungee cords. If these bungee cords work together, they can protect the joints of the feet and ankles from excessive stress, and prevent muscle and tissue damage caused by overpronation. If they do not work properly, a person will be able to see evidence of this in the feet and ankles, particularly in the alignment of the joints.
In addition to controlling forces down through the joints, the body's muscular "bungee cord system" also stores energy that can be used to create strong, powerful movements as this energy is released, much like the forward propulsion of the legs when walking. However, if a person overpronates, the energy stored in the "bungee cord system" is lost, preventing the body from taking mechanical advantage of stored energy in the muscles.
The Big Toe Breaking Mechanism
When weight is transferred correctly through the foot and ankle, the foot should strike the ground on the outside of the heel. Then, the foot and ankle should pronate to load the muscle "bungee cords" and create a powerful release that enables the foot to supinate and transfer weight over the front of the toes. When a person overpronates, however, their body weight continues to collapse toward the midline of the body. So instead of supinating and using the lesser toes to transfer and dissipate forces, the full weight of the body passes through the first joint of the big toe. This is why bunions and calluses are located on the inside border of the foot. They are usually caused by chronic overpronation.
Fortunately, the big toe can act as a break to stop the foot from collapsing too far inward (overpronating). If muscles are used to pull the big toe down into the ground, it creates tension in the arch of the foot and prevents the foot from overpronating. However, people that overpronate have other muscles of the lower kinetic chain that are weak. So, it will be necessary to address the muscles of the big toe in combination with other dynamic exercises to keep the muscle "bungee cord system" fully functional and working together as it should.
Visual Assessments for the Foot and Ankle
To easily get an idea of whether a person overpronates, look at the position and condition of certain structures in the feet and ankles when he/she stands still. When performing weight-bearing activities like walking or running, muscles and other soft tissue structures work to control gravity's effect and ground reaction forces to the joints. If the muscles of the leg, pelvis, and feet are working correctly, then the joints in these areas such as the knees, hips, and ankles will experience less stress. However, if the muscles and other soft tissues are not working efficiently, then structural changes and clues in the feet are visible and indicate habitual overpronation.
The following clues indicate overpronation:
Bunions and Calluses
Bunions, calluses and crooked toes may indicate alignment problems. So, it is important to ascertain the condition of a client's toes. Check the big toe to determine if the first joint of the toe is swollen, has a callus or bunion, and/or looks as though it abducts (i.e., hallux valgus) rather than pointing straight ahead. Also, look to see if the lesser toes seem to "curl up" (i.e., the person has hammer or claw toes). This may be indicative of damage to, or inflexibility of the plantar fascia caused by excessive flattening of the foot.
Using the BOSU® Balance Trainer to Address Overpronation
The soft, dynamic surface of the BOSU® Balance Trainer's (BT) dome surface is ideal for training the foot and ankle complex to load into pronation without collapsing into overpronation. For beginners, the dome can be inflated so that the surface has less movement. Alternatively, deflating the BT allows the foot to move more dynamically, creating an even greater challenge of trying to avoid overpronation when performing the following exercises.
Exercises
The following exercises help retrain the foot and ankle complex to correct overpronation. Exercises may be performed while wearing shoes, or for an even greater challenge, in bare feet.
Duck Stand
This exercise is designed to prepare for the more dynamic BT exercises ahead by waking up the gluteal muscles and teaching clients how the gluteal muscles control the degree of foot pronation. For example, when the glutes contract concentrically, they rotate the leg outward. As the leg rotates outward, the arch of the foot raises (i.e., supinates).
Stand beside the BT with both heels together and feet turned outward. (Note: As you progress, perform this exercise while standing on the BT.) Try to rotate legs outward by tightening buttock muscles while tilting pelvis under. As legs rotate outward, arches of the feet raise up out of pronation. Hold position for 30 seconds.
Big Toe Pushdowns
This exercise is designed to strengthen the muscle of the big toe that holds up the arch of the foot (i.e., flexor hallucis longus muscle). This stops the foot from overpronating.
Stand on top of the BT dome with feet facing forward. Use gluteal muscles to raise the arches of the feet (see previous exercise - "Duck Stand"). Keep arches raised while pushing down big toe into the BT. While pushing down, tension build in the arch on the underside of their foot should be felt. Hold position for 15 seconds.
Movement Directions:
Stand on top of the BT dome with feet facing forward. Use gluteal muscles to raise the arches of the feet (see previous exercise - "Duck Stand"). Keep arches raised while pushing down big toe into the BT. While pushing down, tension build in the arch on the underside of their foot should be felt. Hold position for 15 seconds.
Side Step with Opposite Reach
This exercise is designed to load the "bungee cord system" of the gluteal muscle and its opposite, latissimus dorsi muscle to keep the foot from overpronating. Because the opposite arm swings across the front leg when walking, this exercise creates tension in the muscles all the way from the front foot, across the back of the hips and back, to the fingers of the opposite hand.
Movement Directions:
Stand with left foot on top of the dome of the BT. (Note: For added balance, the right foot can tap on the ground, if needed). Reach right leg out to the side of the BT, and tap the ground while squatting down on the left side and reaching right arm across the left knee. Push down with left big toe while squatting. This activates the arch of the left foot and strengthens all the stabilizing muscles on the left side of the lower body. Return to starting position. Perform 8 to 10 repetitions on each leg.
Step Up and Over
This exercise is designed to integrate skills learned in the Duck Stand, Big Toe Pushdowns and Side Step with Opposite Reach exercises to mimic walking and even running. Using the gluteal muscles and big toe in tandem will prevent overpronation while moving back and forth over the BT in a more effective, balanced motion.
Movement Directions:
Stand with left foot on top of the BT dome. (Note: For added balance, the right foot can tap on the ground, if needed). Extend right foot backwards to the ground and drop hips into a lunge position. Make sure that the right arm rotates across the left leg (this will activate the gluteal muscles on the left side). Now, step through and over the BT into a front lunge with the right leg forward. While lunging forward, the torso and left arm now rotate over the right leg. Throughout the exercise, push big toe down into the BT. Perform 8 to 10 repetitions on both sides.
About the Author:
Justin Price is co-owner of The BioMechanics, a private training facility located in San Diego, CA, that specializes in providing exercise alternatives for sufferers of chronic pain. He is also the co-creator of The BioMechanics Method which is a method for pain reduction that combines structural assessment, movement analysis, corrective exercise and life coaching that teaches trainers how to help clients alleviate chronic pain and improve their function. He was named International Personal Trainer of the Year in 2006 by the worlds' leading organization of health and fitness professionals, IDEA Health and Fitness Association, and has helped thousands of people around the world overcome pain and injury through his methods. For more information about Justin or The BioMechanics Method go to http://www.thebiomechanicsmethod.com/.
References:
Golding, Lawrence A. and Golding, Scott M. Fitness Professionals' Guide to Musculoskeletal Anatomy and Human Movement. Monterey, CA: Healthy Learning, 2003.
Gray, Henry. Gray's Anatomy. New York: Barnes & Noble Books, 1995.
Kendall, Florence P., McCreary, Elizabeth K. and Provance, Patricia G. Muscles: Testing and Function. Philadelphia, Lippincott Williams & Wilkins, 1993.
Myers, Thomas. Anatomy Trains: Myofascial Meridians for Manual and Movement Therapists. Edinburgh, Churchill Livingstone, 2001.
Price, Justin. "A Step-by Step Guide to Corrective Exercise Program Design". Lenny McGill Productions, 2008.
Price, Justin. "A Step-by Step Guide to the Fundamentals of Corrective Exercise". Lenny McGill Productions, 2006.
Price, Justin. "A Step-by Step Guide to the Fundamentals of Structural Assessment". Lenny McGill Productions, 2006.
Price, Justin. "A Step-by Step Guide to the Understanding Muscles and Movement". Lenny McGill Productions, 2008.
Schamberger, Wolf. The Malalignment Syndrome: Implications for Medicine and Sport. Edinburgh: Churchill Livingstone, 2002.
Taylor, Paul M. and Taylor, Diane K. (Eds.). Conquering Athletic Injuries. Champaign, IL: Leisure Press, 1988.
Whiting, William C. and Zernicke, Ronald F. Biomechanics of Musculoskeletal Injury. Champaign, IL: Human Kinetics, 1998.