Athletes of any skill level can be affected by injuries to the muscles and ligaments around the hip. Hip injuries can significantly interfere with sports enjoyment and performance levels, and occasionally they will end participation completely. Excessive pronation and poor shock absorption have been found to be underlying causes of or contributing factors to many hip/leg injuries.1 Orthotics that are custom made to improve the biomechanics of the feet and reduce the extent of pronation can work with chiropractic adjustments to help resolve many sports-related hip problems.
The Overpronation Factor
Busseuil, et al., looked at the foot biomechanics of athletes who reported a recent foot or leg injury and compared them to an uninjured control group.2 The researchers determined those athletes with more foot pronation had a much greater statistical probability of sustaining one of five leg injuries including iliotibial band syndrome (due to excessive tightness of the hip abductor muscles). This study helps us understand how providing appropriate orthotic support to patients involved in sports or recreational activities lowers their likelihood of developing both traumatic and overuse hip injuries.
In the study, 66 injured athletes who ran at least once a week and had no history of traumatic or metabolic factors comprised the study group. Another (control) group of 216 athletes were matched who had no symptoms of lower extremity injuries. The amount of pronation during standing and running at "regular speed" was determined by measuring the angles of the athletes' footprints. This quick and inexpensive method of determining the amount of pronation during functional activities (plantar prints) had been previously investigated.3
The researchers concluded that those athletes with more pronation had a much greater likelihood of having sustained one of the overuse athletic injuries. While both the standing (static) and running (dynamic) prints showed some correlation, the amount of pronation seen in the static weight-bearing footprint was the most predictive of developing an overuse injury. This study helps remind us it's very important to athletic performance and injury prevention to check the alignment of patients' feet in the standing position.
Hip Conditions and Muscle Control
Many hip injuries originate from poor biomechanics and gait asymmetry, especially when running. Smooth coordination of the muscles that provide balance and support for the pelvis is needed for optimum bipedal sports performance. This includes the hamstring muscles and the hip abductor muscles, especially the tensor fascia lata (the iliotibial band). When there is a foot or ankle biomechanical deficit, abnormal motions (such as excessive internal rotation of the entire leg) will contribute to pulls and strains of these important support muscles. The hamstring muscles are a good example.
During running, the hamstrings are most active during the last 25 percent of the swing phase and the first 50 percent of the stance phase.4 This initial 50 percent of the stance phase consists of heel strike and maximum pronation. The hamstring muscles function to control the knee and ankle at heel strike, and to help absorb some of the impact. A 1999 study showed a significant decrease in electromyographic activity in the hamstrings when wearing orthotics.5 In fact, these investigators found the biceps femoris (the most frequently injured of the three hamstring muscles 6) had the greatest decrease in activity of all muscles tested, including the tibialis anterior, the medial gastrocnemius, and the medial and lateral vastus muscles.
Secondary Conditions
Using orthotics to correct excessive pronation and treat hip problems requires an awareness of the various problems that can develop. The following is a list of the pathologies seen in the hip and pelvis, secondary to pronation and foot hypermobility:7
- Anterior pelvic tilt
- Hip adductor muscle strain
- Hip flexor muscle strain
- Hip joint capsulitis
- Iliotibial band syndrome
- Piriformis muscle strain
- Tensor fascia lata strain
- Trochanteric bursitis
These conditions develop much more easily in athletes who push their musculoskeletal systems in order to achieve greater functional performance.
Orthotics Help Hip Problems
Evaluation of foot biomechanics is a good idea for all patients, but is especially necessary for those who are recreationally active or who have experienced hip problems. Excessive pronation and/or poor shock absorption has been shown to be an associated or causative factor in many leg injuries, from the foot itself up the lower leg to the knee, thigh and into the hip joint. The good news is many of these conditions can be prevented with custom-made orthotics.
Athletes need regular evaluations of the alignment and function of their feet in order to avoid potentially disabling hip injuries. Additional preventive measures include wearing well-designed and solidly constructed shoes. When athletes are provided with custom-made orthotics, we can prevent arch breakdown and biomechanical foot problems, and treat numerous injuries to the lower extremities including the hip joints.
References
- Dahle LK. Visual assessment of foot type and relationship of foot type to lower extremity injury. J Orthop Sports Phys Ther, 1991;14:70-4.
- Busseuil C, Freychat P, Guedj EB, Lacour JR. Rearfoot-forefoot orientation and traumatic risk for runners. Foot Ankle Intl, 1998;19:32-7.
- Freychat P, Belli A, Carret JP, Lacour JR. Relationship between rearfoot and forefoot orientation and ground reaction forces during running. Med Sci Sports Exer, 1996;28:225-32.
- Mack RP. AAOS Symposium on the Foot and Leg in Running Sports. St. Louis: Mosby, 1982.
- Nawoczenski DA, Ludewig PM. Electromyographic effects of foot orthotics on selected lower extremity muscles during running. Arch Phys Med Rehabil, 1999;80:540-4.
- Garrett WE. Muscle strain injuries. Am J Sports Med, 1996;24:S2-8.
- Hartley A. Practical Joint Assessment: A Sports Medicine Manual. St. Louis: Mosby YearBook, 1991, p. 571.
