Pronation and Postural Support

In normal biomechanics of the foot and ankle, there is movement from supination to prona-tion and back, during the gait cycle. This transi­tion is necessary for proper shock absorption at heel strike, stability when the foot is flat, and lever­age for an efficient toe-off. One of the most com­mon problem that interferes with effective foot bio­mechanics is excessive pronation. Since the tim­ing of the change from pronation to supination is critical during walking and running, another term for this is "prolonged pronation." This condition occurs as a result of several factors, including loss of the medial longitudinal arch, eversion (tilting) of the calcaneus, or exces­sive dropping of the ta­lus and/or navicular bones. Potential Problems In addition to interfer­ing with gait and de­creasing athletic perfor­mance, excessive prona-tion is important for two other major reasons. There is the likelihood of developing painful foot and ankle disability over time, and (espe­cially important for doc­tors of chiropractic) the probability of transfer­ring abnormal stresses up the lower extremity and into the pelvis and spine. Athletes may suffer from a number of "overuse injuries," which are actually caused by excessive pronation.1 Many times the developing problems go unnoticed for months or years, and it is only when a new walking or recreational program is begun that symptoms arise. Other times it is the painful end stage of abnormal biome- chanics which brings a patient in for care. This article presents a review of the conditions and pa­thologies which are as­sociated with excessive pronation.: In the Foot It isn't surprising that abnormal biomechanics of the foot can cause foot problems. What is unusual is the number of conditions which have been reported to be linked with excessive prona-tion. Table 1 is a list of the foot pathologies which are associated with excessive pronation. In the Lower Leg Many of the muscles that move the foot and ankle and provide support during walking, run­ning, and jumping originate in the lower leg. There­fore, it makes sense that excessive pronation can result in various strains and tendinitis conditions of the lower leg. When abnormal biomechanics is combined with the higher forces of sports activi- ties, even stress fractures can develop.3 Table 2 is a list of the commonly encountered condi­tions in the lower leg associated with excessive pronation. In the Knee Because the knee is a hinge (ginglymus) joint, it moves pri­marily in one plane. When ex­cessive pronation at the foot and ankle causes increased medial rotation to be transmitted up the leg, this rotary motion eventually results in knee symptoms. Knee problems frequently develop in athletes who experience greater rotational forces.4 Some studies have even indicated that this can happen on an acute basis, causing rupture of the anterior cruciate ligament.5 Table 3 is a list of knee problems which can develop from excessive pronation. In the Hip/Pelvis/Spine Unfortunately, there is much less written about the specific conditions of the hip, pelvis, and spine caused by excessive pronation. Because the foot is not nearby, correlation of poor foot biomechanics with pelvic and spinal problems requires additional research. The most important condition for doc­tors of chiropractic is the func­tional short leg created by arch collapse and medial ro­tation of the ankle and leg. This results in a pelvic tilt to the shorter side, and is usu­ally accompanied by a spinal rotoconvexity (scoliosis). This is sometimes known as a "functional scoliosis." since it is flexible and present only during standing. Table 4 is a list of the pathologies which may be seen in the hip, pel- Table 1. Foot pathologies linked to excessive pronation Calcaneal periostitis (heel spur) Navicular stress fracture Hallux valgus Plantar fascitis Hammer toes ^ Sesamoiditis Interdigital neuroma Spring ligament sprain Longitudinal arch collapse Tailor's bunions Medial calcaneal compartment syndrome Tarsal tunnel syndrome Metatarsal calluses Toe extensor muscle spasms Metatarsalgia Table 2. Lower leg conditions linked to excessive pronation Achilles tendinitis Peroneal tendinitis " - *% Fibula stress fracture Tibialis posterior muscle strain/tendinitis , Flexor digitorum longus strain/tendinitis Tibial periostitis i Flexor hallucis longus strain/tendinitis Tibial stress fracture Table 3. Knee problems linked to excessive pronation Anterior cruciate injuries Patellofemoral pain syndrome Chondromalacia patellae Pes anserine bursitis Knee joint capsulitis Table 4. Hip, pelvis, spine conditions linked to excessive pronation Anterior pelvic tilt Iliotibial band syndrome Excessive lumbar lordosis Piriformis muscle strain Functional scoliosis Sacroiliac problems Hip adductor muscle strain Tensor fascia lata strain Hip flexor muscle strain Trochanteric bursitis Hip joint capsulitis vis, and spine with excessive pronation. Conclusion Excessive pronation is associated with many musculoskeletal complaints — from the foot itself, up the leg to the knee, hip, and even the pelvis and spine. The good news is that all of these conditions can be helped with custom-fitted orthotics. Investigation of foot biomechanics is a good idea with all patients, but especially with those who are rccreationally active. Many times, correction of recurring subluxations can only be accomplished when an excessively pronating foot is pro­vided with appropriate orthotic support. Competitive athletes must have regular evaluation of the alignment and function of their feet, in order to avoid potentially disabling injuries. Preventive measures include wearing well-designed and con­structed shoes, and considering orthotic support in those patients at risk for de­veloping excessive pronation. Dr. John Danchik is the seventh inductee to the American Chiropractic Association Sports Hall of Fame. He is the current chairperson of the United States Olympic Committees Chiroprac­tic Selection Program. He lectures ex­tensively in the United States and abroad on current trends in sports chi­ropractic and rehabilitation. Dr. Danchik is associate editor of the Jour­nal of the Neuromusculoskeletal System and the Journal of Chiropractic Sports In­juries and Rehabilitation. He has been in private practice in Massachusetts for 24 years. You may reaach Dr. Danchik at (617)489-1220 or e-mail docforjocs(3)aol. com. References 1. Busseuil C et al. Rearfoot-forefoot orienta­tion and traumatic risk lor runners. Foot & Ankle 1ml 1998; 19(l):32-37. 2. Hartley A. Practical Joint Assessment: A Sports Medicine Manual. St. Louis: Mosby YearBook, 1991:571. 3. Schweitzer ME. White LM. Docs altered bio- mechanics cause marrow edema? Radiology 1996; 198:851-853. 4. Dahlc LK et al. Visual assessment of foot type and relationship of foot type to lower extremity injury. J Orlhop Sports Phys Ther 1991; 14:70-74. 5. Beckett ME et al. Incidence of hyperpronation in the ACL injured knee: a clinical perspective. J Athl Train 1992; 27:58-62.