Achilles Tendinopathy describes an acute strain or rupture of the strongest and longest tendon in the human body, the Achilles Tendon. The Achilles tendon, also named the Calcaneal tendon, handles loads of up to 12.5 times bodyweight and is formed from the joining of two muscles, the gastrocnemius and soleus. Both of these muscles act on the knee and ankle joints enabling us to stand on the balls’ of our feet lifting our heels, flexing our knees so we can squat, walk, run, jump, and absorb shock. The Achilles tendon wraps around the heel bone fascially connecting to the plantar fascia.
The Achilles tendon may be acutely strained or ruptured as the result of an excessive stretch. The Achilles tendon is placed through a stretch/contract transition during the midstance phase of gait when the tibialis posterior and flexor hallucis longus muscles show their greatest activity. Tib. posterior and flex. hallucis longus both build and support the arch of our feet, so if there is weakness there, shown by overpronation or flatfootedness, the Achilles can be subject to more force.
Achilles tendinopathy is an acute injury that has less to do with inflammation, which would be labeled as tendonitis, and more to do with repeated overloading, microtearing, failed healing, and tendon degeneration. Like the majority of tendons, ligaments, and non-muscle tissue in the body, the Achilles tendon lacks a rich blood supply that can help speed recovery.
Factors that increase the risk of Achilles Tendinopathy are improper warm up, overtraining, running on hard surfaces, excessive stair or hill climbing, improper arch support/ footwear, poor conditioning and abruptly returning to activity after a period of inactivity. Wearing high-heeled shoes may lead to shortening of the gastroc/soleus, predisposing women to Achilles tendinopathy. Intrinsic factors include hyperpronation, flat foot, high arches, gastroc/soleus inflexibility or weakness, limited big toe flexion, and limited ankle dorsiflexion. Systemic risk factors include diabetes, hypertension, inflammatory arthropathy, gout, obesity, and the use of corticosteroids or quinolones (broad-spectrum antibiotics).
As hikers, backpackers, and runners, we need to include foot strengthening if we have weak feet, stretching if we have tight calves and hamstrings, adequate training/rest ratios, progressive conditioning, and movement pattern training.
As a bodyworker and movement therapist, I look for the functional patterns as to why an issue like Achilles Tendinopathy is occurring in the first place. Limited ankle range of motion, glute weakness, decreased hamstring/calf strength, and foot hyperpronation are all linked to Achilles tendinopathy. If a client has a history of big toe dysfunction such as bunions, sesamoiditis, plantar fasciitis, or arthritis, there is a possible compensation between decreased big toe flexion which occurs with toe off during the swing phase of the gait cycle, and decreased gluteus medius activation. Observing patterns, compensations, and imbalances in the kinetic chain are my main focus to the treatment of Achilles tendinopathy in addition to manual therapy and strengthening.
The treatment and prevention of Achilles tendinopathy can be fairly straightforward if you are willing to rest and stick to an eccentric training protocol. Alfredson’s model of eccentric exercise includes progressive single-leg heel drops for strengthening the calf and Achilles without overloading the tendon with concentric, or shortening, contractions. “Heel drops should be performed with the knee both straight and bent off of a step, 3 sets of 15 repetitions, 2x per day for 12 weeks. Heel drops should occur slowly on a 4-10 second count. The patient should use the non-injured leg to return to the “heel up” start position, thereby avoiding concentric contractions. Moderate pain during this exercise is acceptable but if the pain is excessive, the patient should assist downward motion with the non-injured leg.” (ChiroUp.com)
Check out this short video on how to perform the Alfredson’s protocol:
For those of us looking to not only prevent Achilles tendinopathy but improve overall leg strength and performance, including eccentric heel drops, are a great exercise. Once the heel drop has been trained, try progressing up to 5 sets of 25 single-leg heel raises to ensure you have adequate lower limb strength and endurance for your sport. This is also one of the requirements for returning to full activity following an Achilles strain or rupture.
Hopefully, none of you ever have to experience an Achilles injury. This post is not meant to place fear in your mind, but inform you of the possibility and risks of overtraining without adequate preparation, rest, and recovery. The research shows us that strengthening protocols with conservative treatment has the best results, so why not include those in your training cycle preventively? Stretching, strengthening, movement patterning, training periodization, and good footwear will help us avoid Achilles tendinopathy thereby enjoying the outdoors pain-free.
The information presented here was pulled from multiple sources including ChiroUp.com, WebMD, and NCBI.