Feeds:
Posts
Comments

Posts Tagged ‘achilles tendon’

Within the region of the Achilles tendon there lives another lesser known muscle and tendon that runs right in front of (anterior to) the Achilles.  The photo to the right should help orient you.  This muscle/tendon is called the Flexor Hallicus Longus (FHL).  My belief is that many FHL problems are misdiagnosed as Achilles tendon issues and are in fact a problem with the FHL.

After years of treating people for “Achilles Tendonitis” I began noticing a trend that many of these people shared.  A lot of people also had very limited movement of their big toes (the fancy Latin medical term of the big toe is Hallux – the “H” of FHL.) This can easily be assessed by the ability to squat down as in the picture below.  If there is restriction, this motion is usually painful and, as in the first picture, the ball of the foot comes off the ground.  In the second picture, the ball of the foot remains on the ground.  Our big toes should be able to move 70 degrees in the upward direction.

restricted range of motion

restricted range of motion

normal range of motion

normal range of motion

The bulk of our calves is mostly made of the two muscles that attach to the Achilles tendon – the gastrocnemius (gastroc) and the soleus.  The gastroc is the muscle that we can see just under the skin which gives our calves the familiar contour.  The gastroc’s job is to create the foot/ankle motion called plantar flexion, which is familiar to most people as rising up on our toes, stepping on the gas pedal and climbing stairs.  The gastroc is also a big running muscle, helping us push off with each stride and if you’re a forefoot or midfoot striker, absorb the impact of landing.  The soleus is just under the gastroc further aiding in the motion of plantar flexion.

There is a third layer of muscle under the gastroc & soleus consisting of 3 muscles, which all run down into the foot.  They are the flexor digitourm longus (FDL), the posterior tibialis (post tib) and the flexor hallicus longus (FHL).  You can Google the first two if you want to know more about them.  I’m going to focus on the FHL here.

The FHL starts along the outside of your lower leg and runs all the way out to the end of your big toe along the bottom of your foot…which is on the inside of your foot.  It makes its devious cross over to the other side right in front your Achilles!

Why would a muscle that controls our toes start way up in our legs?  For the same reason why muscles that control our fingers start in our forearms.  Way back (a few million years ago) when we used to maneuver about the trees using our feet, we had to grip with our toes.  Gripping or flexing (the “F” of FHL) our toes was the main purpose of the FHL.  Nowadays, the main function of the FHL is to stabilize our toes and create a stable platform to push off.   When this muscle gets strained and overly tight we feel pain in one or more of the following places: the ball of our foot, our arch, near our heel or in the Achilles region of our ankle.  It’s rare to feel pain in the muscle itself because the tendon is susceptible to points of high friction in many places.

How do you know if you an FHL problem vs. true Achilles tendonitis?  How do you fix it? If you’ve been stretching your calf properly and consistently and you still have pain, try the following stretch for a few weeks.  Place a one-inch thick, soft cover book on the floor (a phonebook works well) and stand with just your big toe on the book and the rest of your foot on the floor.  Keeping the ball of your foot and heel on the floor, bend your knee forward until you feel a gentle stretch.  Hold for 20-30 seconds.  Repeat 3-5 times.  If this is too painful, open the book half way and try again.  As you adapt to the stretch, add more pages.

FHL Stretch from Michelson & Dunn 2005

FHL Stretch from Michelson & Dunn 2005

If you start noticing positive changes within a few days then your FHL is likely the problem.  It will take several weeks for the pain to resolve completely but you should be running and walking with much more comfort during the recovery phase.

The “L” of FHL is for longus.  Longus is used to describe a muscle that originates outside the body part it moves.  There is also a flexor hallicus brevis that’s located entirely within the foot.

Advertisements

Read Full Post »