Treating achilles tendinopathy using eccentric loading versus shock-wave therapy

A study suggests that we should be using shock-wave therapy instead of just physical therapy (eccentric loading) to promote active recovery for refractory achilles tendinopathy

Top of the morning, sapien. Welcome to Common Sense Medicine, where I try and keep you up to date on the latest and greatest in longevity science. Recently, I’ve gotten more into the idea of training for a triathlon, because I saw some of my friends do it. But I must have gotten too eager, because I got injured (mildly) — I started getting some pain first in my left calf and then the medial heel portion, partly to the calcaneus (heel bone).

So I decided to do some of my own sleuthing because it seemed sub-clinical, and came across a randomized controlled trial conducted by Rompe et al where they used shockwave therapy versus eccentric loading to treat insertional refractory achilles tendinopathy.¹

About the study

The authors recruited 50 patients persisting for 6 months or more despite previous treatments, including NSAIDs, corticosteroids, and physiotherapy. They then randomized them into two groups: one undergoing eccentric loading exercises and the other ones undergoing low-energy shock wave therapy.

Table: Treatment protocols

Then, they measured clinical outcomes of pain, function, and activity using the VISA-A (Victorian Institute of Sport Assessment-Achilles) questionnaire, general assessment outcome for recovery (through a Likert 6-point questionnaire), and pain assessment based on a 3 kg load being applied to the most tender point of the achilles tendon. They assessed outcomes at four months, after which patients were given the chance to switch treatments, and at at fifteen months to conclude the study.

Shockwave therapy provides a greater pain outcome than eccentric loading

The study showed that low-energy shock wave therapy had a more substantial impact on recovery from chronic insertional Achilles tendinopathy compared to eccentric loading exercises. The VISA-A scores rose from 53 to 80 in the SWT group while they only increased from 53 to 63, showing a mean difference of 16.2 points (95% CI: 5.3 to 27.2, p=0.005). The differences for general outcomes and pain reductions were similar, showing a reduced pain burden and more complete recovery.

Patient-reported recovery assessments further supported the efficacy of shock wave therapy. By the four-month follow-up, 64% of patients in the shock wave therapy group reported feeling “completely recovered” or “much improved,” compared to only 28% in the eccentric loading group, resulting in a significant difference (p = 0.02). The high satisfaction rate among patients receiving shock wave therapy was accompanied by a strong preference among eccentric loading participants to “cross over” to shock wave therapy after the initial study period; 18 of the 25 patients in the eccentric loading group switched to shock wave therapy, underscoring the limitations of eccentric loading for treating insertional tendinopathy.

Several secondary outcome measures, including load-induced pain, pain threshold, and tenderness at specified pressures, all favored shock wave therapy. These results indicate that shock wave therapy not only provided immediate symptomatic relief but also led to sustained improvements, suggesting its potential as a superior nonoperative treatment for chronic insertional Achilles tendinopathy.

Should I shock myself?

This study seems promising because it shows that with a lower amount of time, someone could treat their chronic non-insertional Achilles tendinitis through shock wave therapy. Firstly, I think that shockwave therapy is not very accessible in my current state—I have a TENS machine, but not necessarily trying to shell out $15,000 for a shock wave device in the near future. I think that for the mild Achilles tendinopathy that I’m trying to treat, there is a role for TENS-based therapy. One of the limitations of this study is that they allowed people to cross over from one treatment group to the other, which limits the generalizability of the long term results of the shockwave therapy.

I think that TENS based therapy suffers from its own set of drawbacks, and it has been called into question as an ineffective way to treat chronic pain². I think for people who are running short of time, and cannot find the time or the ability to do physiotherapy and eccentric loading, then it can provide a very attractive way to tackle their chronic pain. I think for me, it makes more sense to focus on yoga for the short term as I try and build up my mileage in the gym and focus more on my hypertrophy and strength building goals as I build up my weight.

When focused on a more mild, protective form of therapy, I am curious to see how the eccentric loading performs versus the shockwave therapy. I will continue to try and focus on yoga, mobility exercises, and others for now because it is a more cheap form of therapy but will try and add in some sessions of TENS as I am trying to strengthen the achilles tendon as I am trying to work on increasing mileage of my runs.

The benefits of having different therapy modalities

There’s a lot to be said for using various therapy modalities to treat running injuries, especially since many injuries occur from trying to increase speed or distance too quickly. I recently attempted to increase my mileage by more than 5% per week, which unfortunately led to an injury. I've noticed that getting more sleep always helps with recovery, so I’m hoping to prioritize rest as I train for longer distances. Knowing that I can opt for a quick and effective therapy like TENS is also reassuring; this shock-wave-type therapy can provide relief while I work on active recovery with eccentric exercises.

For now, I plan to continue my Zone 2 sessions but will switch to biking instead of running for the next few weeks to allow for healing. I also intend to make recovery a focus on my rest days, dedicating one cardio day each week to yoga or other recovery activities. Prioritizing sleep will be essential, as it's one of the key pillars of longevity. Overuse injuries are clearly multifactorial, so our treatment approaches should be just as multifaceted.

REMEMBER, IT’S JUST COMMON SENSE.

Thanks so much for reading! Let me know what you thought by replying to this email.

See you next week,

Shree (@shree_nadkarni)

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The information provided here is not medical advice. This does not constitute a doctor patient relationship and this content is intended for entertainment, informational, and educational purposes only. Always consult with a doctor before starting new supplementation protocols.

1. Rompe JD, Furia J, Maffulli N. Eccentric Loading Compared with Shock Wave Treatment for Chronic Insertional Achilles Tendinopathy: A Randomized, Controlled Trial. JBJS. 2008;90(1):52. doi:10.2106/JBJS.F.01494

2. Gibson W, Wand BM, Meads C, Catley MJ, O’Connell NE. Transcutaneous electrical nerve stimulation (TENS) for chronic pain ‐ an overview of Cochrane Reviews - Gibson, W - 2019 | Cochrane Library. Accessed November 2, 2024. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD011890.pub3/full