Tendonitis is arguably one of the most common overuse injuries among the physically active. Also known as tendinitis, it can occur anywhere between a tendon's muscular origin and its bone insertion, often as a result of overuse injuries, workplace trauma or biomechanical problems. Each of the long muscles can be affected, including inverters.
Description
Tendons are fibrous structures that connect muscle to bone and transmit forces to enable joint motion Although the term tendonitis means "inflammation of the tendon," many practitioners argue that the process behind the disorder is not true inflammation, but rather degeneration. Mechanical overload and repetitive strain are thought to cause the tendons to degenerate due to such factors as: misalignment; poor muscle flexibility, muscle weakness, or imbalance; poor design or excessive duration, frequency, or intensity of activity.
Special Motions
The muscles in your lower leg and foot produce four specialized actions: dorsiflexion and plantarflexion at the ankle joint; and inversion and eversion between the bones of the foot itself. Dorsiflexors and plantar-flexors move the foot upward and downward, respectively, while everters are muscles that turn the sole of the foot outward, away from your body's midline. Inverters produce the opposite motion, turning the sole of the foot inward. Inverters include the tibialis anterior and tibialis posterior muscles.
Posterior Tibial Tendonitis
The tibialis posterior tendon travels behind your inner ankle bone to insert on the inner side of your midfoot. It stabilizes your arch and decreases flatfoot by distributing weight across your forefoot, and it moves your foot down and inward by shifting weight to the outer side of the foot. Over-pronation, or the excessive upward and outward movement of the foot is a bio-mechanical problem that specifically contributes to posterior tibial tendonitis.
Anterior Tibial Tendonitis
The tibialis anterior muscle travels along the outer side of your shinbone, passes in front of the ankle to insert on the inner surface of two mid-foot and forefoot bones. It is a powerful dorsiflexor and inverter, and its dysfunction can lead to a slapping gait. According to Virginia Commonwealth University physician Michael Simpson, anterior tibial tendon tendonitis is a typical overuse injury in patients older than 45 years, although it can also occur in distance runners and soccer or football players.
Symptoms
Posterior tibial tendonitis produces pain and swelling posterior to the inner side of your ankle. The pain may radiate upward to your lower leg and is typically worse with weight bearing, forced inversion and plantar flexion. You may thus distinguish it from anterior tibialis tendonitis, which causes pain over the anterior ankle and is usually accompanied by weak or painful dorsiflexion.
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Treatment
Simpson notes that the treatment regimens for both types of inverter tendonitis focus on protection, relative rest through a short leg cast, ice, compression, elevation, medications, and tendon strengthening exercises. Posterior tibial tendonitis may also require orthotics to decrease pronation. Some cases may require steroid injections for persistent pain or surgical treatment.
Prevention
Warming up and stretching before a physical activity are simple, yet effective ways to reduce your risk of developing posterior or anterior tibialis tendonitis. Equally important are periods of rest in-between activities. You should also limit repetitious tasks in the workplace and home life that put repetitive strain on your inverter muscles.
References
- University of Michigan Medical School: Anterior & Lateral Leg & Foot
- "Bope: Conn's Current Therapy 2010;" Edward T. Bope, M.D. et al.; 2010
- First Consult: Tendinitis; Michael Tuggy, M.D. et al.; 2010
- "American Family Physician" journal: Tendinopathies of the Foot and Ankle; Michael Simpson, D.O. et al.; November 2009
