In the past twelve months, I’ve seen an increase in the number of runners and triathletes who have come to me with Anterior Compartment Syndrome (ACS), looking to explore corrective running technique coaching as an option in an effort to run pain free and avoid surgery to relieve their pain – which is often their other remaining option.

ACS is a Chronic Exertional Compartment Syndrome of the lower anterior compartment of the lower leg. It is suggested that about 69% of those diagnosed with ACS are runners.

In such cases, I’m always quick to point out from a biomechanical stand-point, that while changing a heel-striking runner with ACS to a mid/forefoot strike pattern makes sense, there is a distinct lack of good research backing this coaching approach up. In his blog Running Research Junkie, Podiatrist Craig Payne does a great job of looking at the limited research, and subsequent clinical and coaching implications.

Despite this lack of solid research, the common consensus seems to be that runners with ACS respond very well to running gait retraining – learning not to heel-strike, instead adopting a forefoot or midfoot strike pattern.

My coaching experience certainly seem to back this up, with every case I’ve personally seen. I’d love to see this anecdotal evidence backed up with research from randomized controlled trials on a large scale.

Gait Retraining for Anterior Compartment Syndrome

Here’s a quick video showing the changes we made to the running form of a ACS sufferer in one morning working together at the track. Clearly his new form is a little unrefined and will take time to reinforce, with practice.

The reason I wanted to share this video is to demonstrate the difference in loading pattern around the ankle between the original heel-striking pattern, and the forefoot striking pattern post coaching intervention.

Heel-Striking Pattern: As the heel strikes the ground and loads the rear foot, the response to this loading of the heel is for the forefoot to drop to the ground until the foot is flat on the floor. This loading response uses the heel as a kind of pivot, creating a plantar flexion moment around the ankle, which Tibialis Anterior, the meaty muscle in the front and outside of your shin, has to work hard eccentrically to control. It is usually this load on Tibialis Anterior which exacerbates ACS in runners.

Forefoot or Midfoot Striking Pattern: As you can see on the video, without the heel strike, we’ve taken away the ‘pivoting on the heel’ action from that we see in heel-striking gait, meaning that Tibialis Anterior doesn’t have to do nearly as much work as the foot lands on the ground and loads.

As we change a runner’s gait pattern. It is important to note that one of the biggest effects on the body is the redistribution of force and loading. Both in terms of external forces and those affected by changes in muscle activation patterns. The body needs time to adapt to the new loading profile – in this case particularly the calf complex. The runner in the above video is a great example – while the new forefoot striking running technique resolved the ACS symptoms, the initial weeks were spent managing calf tightness, and not doing too much running, too soon. As with many things running related, lower leg loading is a trade-off!

Words of Caution

For clarity, I’ll stop short of suggesting that we should be coaching all runners with ACS to forefoot or midfoot strike. Even when research eventually tells us that we perhaps should (my gut feeling is that it eventually will), each case should be approached and judged on it’s own merits.

It is also potentially possible that simply learning to land with less of a pronounced heel-strike will also reduce the eccentric loading on Tibialis Anterior enough to reduce symptoms. Pete Larson puts it well in saying ‘All Heel Strikes Are Not Equal’.

Of course, as with any runner newly adopting a midfoot or forefoot running style, those with a history of Anterior Compartment Syndrome should give the plantar flexors (calf muscles) time to adapt to the increased demands of the new loading profile. I feel this especially important in ACS sufferers as that already clearly have a serious muscle imbalance in the lower leg.

Last updated on March 2nd, 2021.