Kinesiology THURSDAY – Lateral Ankle Sprain

Have you ever sprained an ankle and then re-sprained the same ankle over and over again? Understanding the kinesiology of a lateral ankle sprain holds the key to ending this cycle of injury. And one of the keys involves a muscle that doesn’t even cross the ankle.
The anterior talofibular ligament is the most commonly torn ligament in an ankle sprain as it checks against excessive plantar flexion and inversion. But the first line of defense against tearing this ligament is a lateral ankle muscle, the peroneus longus. And the peroneus longus has an interesting connection to your lateral hamstring, the bicep femoris, by way of their attachments at the proximal fibula. That’s a lot of words, but check out this picture:

When you sprain your ankle, you place a rapid stretch on the peroneus longus, causing it to “bowstring” and push the distal fibula forward and up. If the fibula becomes subluxed in this way, the bicep femoris will become chronically tight. These two muscles are in a tug-of-war. If one muscle is short and tight, the other will become long and weak. That means if the bicep femoris becomes tight, the peroneus longus becomes weak and less effective at protecting against another ankle sprain.
How do we know this has happened? Because trigger points show up in muscles that are chronically short and you will often find tenderness in the bicep femoris tendon just an inch or so above the knee joint line.
The fix is simple. Master the revolving triangle pose. Give it try. If you are always spraining the same ankle, I’ll bet this is harder to do with that leg in front.

If you are a clinician reading this, here is a short list of things to check on your patients who chronically sprain their ankle:
- Subtalar joint eversion mobility
- Ankle dorsiflexion (because ankle dorsiflexion is required for the ankle to pronate)
- Posteriorly subluxed fibular head (fix it with a mobilization or muscle energy technique)
- Trigger points in the bicep femoris (use soft tissue mobilization or myofascial release)
Conventional thinking says: Strengthen the peroneus longus to prevent ankle sprains.
Real World Thinking says: Restore subtalar joint eversion and dorsiflexion and stretch the bicep femoris (with a revolving triangle pose) to prevent this from recurring.
Here’s a link to our Wipe Out Lateral Ankle Sprain program if you want some more ideas. Or pass it on to a friend who keeps twisting their ankle.
Because nobody has time to be in pain.
Until next time…

Kind Regards,
MoveWell Academy
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