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90 m a s s a g e & b o d y w o r k s e p t e m b e r / o c t o b e r 2 0 1 8 way weight is distributed through the lower extremity (Image 3). Because the knees are bending inward, there is a tendency for more weight to be pushed toward the medial side of the foot, which can produce overpronation during gait. A valgus angulation is one in which the distal end of a bony segment deviates in a lateral direction. At the knee, the valgus angulation is named for the lateral deviation of the distal tibia. There can also be a valgus angulation to the calcaneus where the distal end of the calcaneus deviates in a lateral direction (Image 4). Calcaneal valgus is also called subtalar eversion. Calcaneal valgus is generally visible in a standing position and is best viewed from the back side of the heel. The heel will appear to be angling in a lateral direction. This postural deviation can also be viewed from the front side of the foot and causes a small section of the heel to stick out toward the lateral side of the foot. Since only a small portion of it is visible sticking out to that side, it is sometimes called a peekaboo heel. Overpronation can also be a cause of other lower extremity disorders. Plantar fasciitis, tarsal tunnel syndrome, Baxter's neuropathy, and posterior shin splints may all be aggravated from overpronation, especially in runners. There is also a strong likelihood that overpronation plays a major role in a condition called hallux valgus, which eventually leads to the formation of bunions on the medial side of the foot at the metatarsophalangeal joint. As noted above, there are structural challenges that may point to the possibility of overpronation. However, because pronation is really a dynamic movement and not just a static position, it is best evaluated during the gait cycle, such as watching a person's foot strike and gait pattern on a treadmill. However, that is generally not practical for most massage therapists. Another factor that can be helpful in recognizing overpronation is examining the wear pattern on the bottom side of the client's shoe. This will only work if the shoes have been worn a significant amount so that some wear pattern is evident. A person who overpronates will tend to have a greater degree of wear on the medial side of the shoe. TREATMENT CONSIDERATIONS In traditional orthopedic approaches, overpronation is generally addressed with orthotics to help change the biomechanical pattern of the foot and ankle complex. The goal is to restack the foot and ankle complex in a more vertical position and prevent it collapsing toward the medial side and overpronating during weight bearing. Another common treatment strategy is to encourage strengthening of the tibialis posterior and other associated muscles that resist overpronation. It is challenging to target this specific group of muscles, but various foot and ankle movements can be done with varying levels of resistance to help develop greater strength in these muscle groups. There can be a fundamental error with this approach, however. You can develop greater strength in a muscle group, but if the motor pattern ingrained in the nervous system still allows for dysfunctional mechanics and perceives this as normal, increasing strength in those muscles is not necessarily going to change the dysfunctional mechanics. As a result, the foot during the gait cycle. However, if a person is significantly overweight, the soft tissues that maintain the foot's arch are not able to withstand the compressive loads and the arch can collapse, causing the foot to roll toward the medial side. The loss of an adequate arch can be seen in a static standing posture, and is also called pes planus or flat foot. Keep in mind that you don't have to be overweight to have pes planus, as people can have this type of foot architecture genetically. The excessive medial roll of the foot is even more apparent during the gait cycle and this is when the overpronation occurs, as the foot rolls too far toward the medial side during its weight-bearing stance. Foot architecture is not the only biomechanical challenge that can lead to overpronation. Faulty knee alignment is another cause. Genu valgum, also known as knock-knees, causes a change in the 4 Posterior view of the right foot showing lateral deviation of the distal calcaneus in calcaneal valgus. Mediclip image copyright (1998) Williams & Wilkins. All rights reserved.