Achilles tendinopathy is probably one of the more common issues I see – especially in runners!
It generally tends to occur due to overuse and the tendon not being able to withstand or heal adequately between loadings. It can result in pain and disability and can sometimes be difficult to rehab (especially if it is insertional). It has an incidence rate of 2.35 per 1000 in the adult population. Recreational runners have a 36% likelihood of it occurring, whilst elite long-distance runners have 52% likelihood over their lifetime!
Conservative treatment is often preferred, with a progressive exercise program showing the best results in the literature.
The most commonly used program was developed by Alfredson et al (1998) and involves eccentric contraction loading. Eccentric loading refers to the lengthening of the muscle whilst still under contraction – think of the lowering portion of a bicep curl: the bicep concentrically contracts whilst lifting the weight but during the lowering portion the muscle is still contracting as it lowers the weight otherwise you would drop it pretty fast!
The Alfredson protocol consists of 3x15 loaded calf eccentric raise with both the leg straight and the knee bent, twice a day, for 12 weeks.
Whilst this is the most favoured protocol, 45 % of individuals do not see improvement!
Other programs such as heavy slow resistance, concentric/eccentric and concentric/eccentric progressing to eccentric contraction loading yielding variable results. This is possibly due to optimal load, rep, sets etc being currently unknown.
There is tentative evidence that a modified “do as tolerated” Alfredson protocol is more effective in reducing pain and disability in the short term but both are equally effective in the long term. It has been suggested that eccentric contraction loading is no more effective at improving pain or function than concentric/eccentric programs. However, the authors of the systemic review did note that caution was required when interpreting results due to methodological quality differences between the studies involved.
There was an interesting study published in 2019 which combined specific collagen peptides with a calf-strengthening exercise program. Results suggested that subjects did show improvement when taking the supplements, HOWEVER, the study was financially supported by a company that made collagen supplements…. so perhaps hold the horses before you run out and bulk buy collagen. Hopefully further research in this area will help to clarify.
If you think you have Achilles tendinopathy you can follow the Alfredson protocol yourself - its pretty readily available on the internet. But I honestly believe your best bet is to get assessed by a rehab professional who can design you program dependent on your individual issues. This is rarely an injury that gets better by itself.
Alfredson, H., Pietilä, T., Jonsson, P., & Lorentzon, R. (1998). Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. American Journal of Sports Medicine, 26(3), 360–366. https://doi.org/10.1177/03635465980260030301
Head, J., Mallows, A., Debenham, J., Travers, M .J., & Allen, L. (2019). The efficacy of loading programmes for improving patient-reporrted outcomes in chronic midportion Achilles tendinopathy: A systemic review. Musculoskeletal Care, 1-17. DOI: https://doi.org/10.1002/msc.1428
Praet, S. F. E., Purdam, C. R., Welvaert, M., Vlahovich, N., Lovell, G., Burke, L. M., Gaida, J. E., Manzanero, S., Hughes, D., & Waddington, G. (2019). Oral supplementation of specific collagen peptides combined with calf-strengthening exercises enhances function and reduces pain in Achilles tendinopathy patients. Nutrients, 11, https://doi:10.3390/nu11010076