Achilles tendinopathy is one of the most frequent overuse injuries causing pain in the ankle. Most often seen in runners, but also those participating in track and field, racquet sports, volleyball and soccer. It is usually associated with an increase in physical activity, training or overuse of the achilles tendon. At times it may also present in middle-aged individuals that are overweight.
Why this happens
The main role of tendons is to connect muscle to bone to provide stability, transmit force from when the muscle contracts, and also absorb external forces to assist muscle. For example, when you stand up onto your toes, the calf muscles work to lift the heels off the floor. The force that the calves produce, get transmitted by the achilles tendon, to the heel where it attaches to. During running, the achilles tendon can take up to 12.5 times the load of your body weight.
With tendinopathies there is an imbalance between the amount of work the tendon is doing, and how much it can tolerate, or time allowed to recover. This leads to a poor healing response, along with some degeneration and disorientation of the collagen within the muscle fibres. Typically, the main reported sign is pain, especially at the start of a training session, easing as you "warm up", and then worsening again at the end. In more severe cases, the pain may last throughout the entire training, affect general daily activities and involve swelling.
What do I do?
Addressing the risk factors
Identifying the cause and potential risk factors is an important place to start. Poor ankle range, foot alignment and reduced movements at the foot are internal risk factors related to achilles tendinopathy, as are conditions such as obesity, hypertension and diabetes. Externally, running technique, faulty equipment (such as poorly fitted shoes), and environmental factors can also lead to increase loading of the achilles tendon and developing a tendinopathy.
Load management
When tendons are loaded, with adequate rest, they can adapt and get stronger. However, when there is too little rest or the load is too much for it to handle, it can start causing harm. Therefore reviewing your usual activities and training plan can be a great place to start, to strike to balance between work and rest. Hiking, running, or swimming can all have the potential to strengthen the tendon or lead to achilles tendinopathy.
Activity modification
A key part of recovery is therefore identifying the activities that aggravate the pain, and/or may have contributed to the development of achilles tendinopathy in the first place. Complete rest is usually advised against, instead utilising active rest by replacing activities that cause pain such as replacing painful running with cycling or daily walking. Alternately, maintaining your usual activity but modifying the intensity or duration to keep the pain levels under 5/10 on the pain scale.
Exercise
Exercise has been shown to not only decrease pain but also increase the function of the achilles tendon. Specifically, what seems to work best is performing eccentric exercises, and slow-speed exercises with heavy load targeting the achilles tendon.
Eccentric exercises are ones where the muscle is lengthening while under load. In the context of the achilles and calf muscles, lifting your heel to stand up on your toes is a concentric contraction. From there, if we were to control the descent and resist gravity by very slowly bringing the heels back to the floor, it would be a form of eccentric contraction, beneficial for tendinopathies.
Alternately, using slow-speed exercises with heavy loads has also been shown to be effective in managing achilles tendinopathies. This method involves performing 3 heel-raise exercises at the speed of 6 seconds per repetition using a seated calf-raise machine with knees bent, standing with knees straight and barbell on shoulders, and leg-press machine with legs straight. Starting with 3 sets x 15 repetitions and progressing to 4 sets x 6 repetitions, over a 12-week program.
Other treatments
Traditionally, other treatments such as dry needling, massage, and stretching have also been used. While currently there is not much evidence supporting the use of these to treat achilles tendinopathy on their own, in combination with exercise, they can provide some additional pain relief and improvements to ankle range.
Key points
Achilles tendinopathy is a common condition, particularly in runners. Structuring adequate rest/recovery following training and exercise and manage how much you are doing, identifying risk factors, and maintaining healthy tendons with exercise is key. As with most injuries, seeking help and treating it early can allow for a better recovery and limit the time spent away from the activities you enjoy.
References
Achilles tendon rupture; Assessment of nonoperative treatment. Scientific Figure on ResearchGate. https://www.researchgate.net/figure/The-anatomy-of-the-Achilles-tendon-and-the-suralis-muscle_fig1_262230849
Longo, U. G., Ronga, M., & Maffulli, N. (2018). Achilles tendinopathy. Sports medicine and arthroscopy review, 26(1), 16-30.
Maffulli, N., Sharma, P., & Luscombe, K. L. (2004). Achilles tendinopathy: aetiology and management. Journal of the Royal Society of Medicine, 97(10), 472-476.
Martin, R. L., Chimenti, R., Cuddeford, T., Houck, J., Matheson, J. W., McDonough, C. M., ... & Carcia, C. R. (2018). Achilles pain, stiffness, and muscle power deficits: midportion Achilles tendinopathy revision 2018: clinical practice guidelines linked to the International Classification of Functioning, Disability and Health From the Orthopaedic Section of the American Physical Therapy Association. Journal of Orthopaedic & Sports Physical Therapy, 48(5), A1-A38.