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Achilles Tendon – May Newsletter

Achilles Tendon Pain in Runners

by John Fiore, PT

map of where the achilles tendon is locatedThere are 4.1 million runners in the United States which is a 30% increase since 2000.1 Nearly 80% of runners sustain at least one overuse running injury per year,2 and 70% to 80% of these injuries occur between the knees and the feet.3 The most common running injuries in descending order are patellar tendonitis, plantar fasciitis, iliotibial band syndrome, patella femoral pain syndrome, shin splints, Achilles tendon pain, hamstring strain, stress fractures, and ankle sprain. While Achilles pain is not the most common lower extremity injury, runners who have experienced Achilles pain know how challenging timely recovery from this injury can be.

The Achilles tendon is one of the largest tendons in the body. It is formed by the gastrocnemius and soleus muscles and serves to attach these lower leg (calf) muscles to the heel (calcaneus) bone. Unique to the gastroc-soleus-Achilles complex is the fact that this muscular- tendon group crosses three joints (knee, talocrural ankle joint, subtalar ankle joint). The Achilles tendon, therefore, is responsible for powering push-off during running and absorbs torsional stress placed upon the associated lower extremity joints. Achilles tendon soreness is common in runners. A rapid increase in running mileage, a drastic change in shoe cushioning or shoe drop, or a significant increase in hill running can all lead to Achilles pain. Poor calf muscle length and mobility as well as poor proximal hip and core functional strength also results in increased Achilles tension during running.

Soreness in the Achilles must not be ignored due to its limited blood supply which can make healing and inflammation reduction challenging. Acute Achilles tendonitis symptoms include pain during the push-off phase of walking or running, tenderness to palpation a few inches above the calcaneus. Acute symptoms may also include a “squeaky” sensation in the Achilles tendon as you move your foot up and down in to dorsiflexion and plantarflexion. This “squeaky” sensation represents inflammation in the Achilles tendon sheath and warrants immediate rest, ice, and medical treatment to reduce inflammation. Chronic Achilles inflammation and soreness results in the formation of a thickened “knot-like” structure within the
Achilles and is referred to as Achilles tendinosis or Achilles tendinopathy. The thickened tendon represents tissue composition changes or scar tissue formation which will not resolve with rest alone.

Treatment of Achilles tendonitis in its early stages should include complete rest from running or any painful activities. It is vital to reduce inflammation by modifying activity level. Anti-inflammatory medication may be prescribed, and ice-elevation will aid in pain reduction. Because the blood supply in the Achilles is limited, healing may take some time. A physical therapist will help determine the underlying cause of your Achilles symptoms as gastroc-soleus or proximal weakness or a muscle imbalance resulting in poor running mechanics. If acute Achilles tendonitis is not treated in a timely manner or if symptoms are ignored, then Achilles tendinosis may develop. The associated tendinosis “lump” of scar tissue decreases the elasticity of the Achilles and may lead to bone irritation at the Achilles attachment (calcaneus). Addressing the scar tissue with properly applied physical therapy cross friction massage, instrument assisted soft tissue mobilization (IASTM), and anti-inflammatory modalities such as Iontophoresis are beneficial. If symptoms do not resolve in a timely manner, orthopedic options such as platelet rich plasma (PRP) injections should be considered. Once pain is gone, running mileage and uphill running should be resumed very gradually. Strengthening the Achilles tendon and calf musculature in an eccentric (lengthened) manner as well as gradual tissue loading will reduce injury recurrence.

Do not ignore Achilles pain. See treatment immediately to expedite your return to running. Because of the unique dynamic musculoskeletal forces and complex synthesis of movement involved in running, treatment of running injuries must not focus solely on static, passive interventions. Physical therapy is a vital component in returning to full activity level following an Achilles tendon injury.
Rest and pain relief alone will not insure a full return to running. A physical therapist with experience treating running specific injuries and a firsthand understanding of the mechanics of running will insure a successful return to running. Learn more about our comprehensive running and physical therapy services at www.sapphirept.com.

1 Wilk B, Muniz A, Nau S. An Evidence-based Approach to Orthopaedic Physical Therapy: Management of Functional Running Injuries. Orthopaedic Physical Therapy Practice. 2010; 22:213-216.
2 Van Gent RN, Siem D, van Middelkoop K, et al. Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review. J Sports Med. 2007; 41:469-480.
3 Ballas M, Tyrko J, Cookson D. Common overuse running injuries: Diagnosis and management. Am Fam Physician. 1997: 55(7):2473-2484.

Muscle of the Month: The Obscure Plantaris Muscle

by John Fiore, PT

The plantaris muscle is an obscure and little known muscle located behind the knee (popliteal fossa). While many runners have first-hand knowledge of Achilles injuries due to overuse, biomechanical compensations, or training errors, few have heard of the plantaris muscle. Injury to the plantaris muscle fairly rare, but ruling out a plantaris strain is important to insure effective treatment of Achilles and calf (gastroc-soleus muscle group) injuries.

The plantaris muscle is a thin band of muscle located behind the knee with its origin on the posterior supracondylar line of the femur and the popliteal ligament. The long, thin tendon of the plantaris muscle forms the medial border of the lateral gastroc (calf) muscle and extends distally along the medial aspect of the Achilles tendon, inserting on the calcaneus (heel) bone.i ii The action of the plantaris includes assisting in flexing the knee and plantarflexion of the ankle. Commonly mistaken for a nerve due to its long, thin tendon, the motor function of the plantaris is insignificant, making it a common choice for surgical tendon grafts and reconstruction procedures in other areas of the body. Collectively, the gastrocnemius, soleus, and plantaris musculature comprise the triceps surae muscle group, all of which are innervated by the tibial nerve.

Despite its diminutive size and function, injury to the plantaris is painful. The most common mechanism of injury occurs while stepping or running downhill (eccentric load) with a fully extended knee. A “pop” is often reported in the back of the knee and an injury to the gastroc or soleus musculature may occur concomitantly. Posterior knee pain and swelling may occur, and rest-ice is an appropriate initial treatment. Gradual return to function is aided by manual release and pain-free loading-eccentric strengthening when tolerated without discomfort.

It should be noted that pain at the tendinous attachment of the plantaris on the medial calcaneus may be confused for Achilles tendinitis. Proper stress testing, palpation, and differential diagnosis is necessary to effectively rule out a plantaris contribution to Achilles symptoms.

Outline of where the muscles are - Plantar Flexors
Photo: http://anatomymedicalook.com/wp-content/uploads/2018/01/plantarus-leg-muscle-muscle-anatomy-skeletal-muscles-groin-muscles-calf-muscles.jpg

i Delgado GJ, Chung CB, Lektrakul N, Azocar P, Botte MJ, Coria D, Bosch E, Resnick D. Tennis Leg: Clinical US Study of 141 Patients and Anatomic Investigation of Four Cadavers with MR Imaging and US. Radiology. 2002;224:112–119. [PubMed]
ii Helms CA, Fritz RC, Garvin GJ. Plantaris Muscle injury: Evaluation with MR Imaging. Radiology. 1995;195:201–203. [PubMed]

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