Equinus: the key to Plantar fasciitis and Achilles Tendinopathy

As a Crossfit trainer I have a hate hate relationship with tendon pain: I hate it, it hates me. Nevertheless, I have to relieve symptoms, actually fix the issue, while getting my athletes back into training. Myself included. Ive suffered for from tendon pain for years. Thankfully, I can now fix it!

This is one of several articles that gives you the science behind popular tendon pains. This article in particular focuses on the cause of Plantar Fasciitis and Achilles tendinopathy.

The key to fixing these issues is understanding “Equinus”.

Equinus is often defined as a “condition in which the upward bending motion of the ankle joint is limited. Someone with equinus lacks the flexibility to bring the top of the foot toward the front of the leg. Equinus can occur in one or both feet. When it involves both feet, the limitation of motion is sometimes worse in one foot than in the other” ( this definition has been copied and pasted all over the internet with no credit, so I don’t know who to credit!)

There are several possible causes for the limited range of ankle motion. Often, it is due to tightness in the Achilles tendon or calf muscles (the soleus muscle and/or gastrocnemius muscle). In some this tightness is present at birth, and sometimes it is inherited. Never ever say your parent didn’t give anything!

back of the leg!

Others acquire tightness from being in a cast, on crutches or frequently wearing high-heeled shoes. Sometimes it’s a bone blocking ankle motion and one leg being shorter than the other. But pretty much, through pursuit of an inactive lazy lifestyle away from the gym, you shorten your calf muscles, like leaving your feet hanging over the side of a chair (I do this all the time!!). In short you worked to get your pain. Enjoy the fruits of your labours!

The relationship between equinus and plantar fasciitis is pretty much nailed to the mast. Amis has written extensively on the role of equinus and foot mechanics.( Amis J. The split second effect: the mechanism of how equinus can damage the human foot and ankle. Front Surg. 2016; 3:38.) “There can be no more room for the standard thinking that these resultant foot and ankle problems arise just because we are getting older or we are obese or they are just random, or that an equinus contracture is only a part of the equation. Equinus is the equation.”

Patel and DiGiovanni found 80% of patients with plantar fasciitis (either acute or chronic) have an underlying equinus issue. (Patel A, DiGiovanni B. Association between plantar fasciitis and isolated contracture of the gastrocnemius. Foot Ankle Int. 2011; 32(1):5-8.)

Cheung and mates ( Cheung JTM, Zhang M, An KN. Effect of Achilles tendon loading on plantar fascia tension in the standing foot. Clin Biomech. 2006; 21(2):194-203.) observed that as tension increases on the Achilles tendon due to tightness, there is a corresponding increase in tension in the plantar fascia. The increase in tension on the plantar fascia due to equinus was up to twice that of body weight. You’ll remember the fat fascists moan about the effect of over weight on foot issues yet the Achilles tendon has significantly more influence on the plantar fascia. It’s not difficult to see why lengthening the Achilles tendon with the correct stretching regime results in Plantar Fascia stress relief.

This is good news and another great reason why your should get one of my free fix your plantar fasciitis/Achilles tendinopathy courses.

A study by McNamee examined the risk factors for developing plantar fasciitis in runners ( McNamee MJ. Analysis of plantar fasciitis risk factors among intercollegiate and recreational runners: a matched case-control study. Thesis submitted to the Graduate Council of Texas State University, May 2016.)

This study identified “strong evidence of a link between limited ankle dorsiflexion and plantar fasciitis.”. In fact every time you muck up your training, or lifestyle in general and reduce your ankle range of motion by a measly one degree the risk factor for plantar fasciitis increased by 14.6 percent. It’s certainly worth noting that arch angle and body mass index (BMI) did not significantly affect plantar fasciitis risk. This flies in the face of accepted wisdom that plantar fasciitis and achilles tendinopathy is Gods punishment for fat people with weird feet .

Sullivan ( Sullivan J, Burns J, Adams R, et al. Musculoskeletal and activity-related factors associated with plantar heel pain. Foot Ankle Int. 2015; 36(1):37-45.) blamed increased activity, decreased ankle joint dorsiflexion along with reduction in foot and ankle strength increased the risk of plantar fasciitis in the general population. To be honest there was also a correlation with those having a higher BMI

Its worth reflecting that a higher BMI may not reflect obesity in athletes, the extra muscle mass contribute to and enhances the load going through the tendons and fascia.

Whilst there are lots of different methods for measuring dorsi flexion, when designing my plantar fasciitis course, I opted for the ankle wall test, rather than the numerous attempts at identifying an ankle angle measurement!

If you are in east London, you can come and see me and I’ll fix this for you ( or show you the drills) it’s andrew@andrewstemler.com or you can just get one of my free courses and cut me out!!

If not, join the mailing list as I’ll send more free stuff out soon!

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