Thread by @37cycles

1/ Another THREAD on nerve entrapment...

This time the victim is the TIBIAL NERVE (TN).

“Tibia” is Latin for “shinbone” AND “flute”... but what about a “flute” made of “shinbone”??

Yep, that happened. Here’s a copy of a Tibial Flute originally made 10,000 yrs ago in Germany...

2/ Time for a little anatomy review.

The TN splits off the sciatic nerve and is sometimes called the “Posterior Tibial Nerve” in the lower leg.

3/ The TN is commonly vulnerable to entrapment at 2 sites:

1) Tibial Tunnel (TT)
2) Proximal Soleus (SSS... explained later)

Let’s dive into 1)...

4/ The TT travels along the posterior-medial ankle,

has the flexor retinaculum as its ceiling and
its bony floor consists of the posteromedial talus, the medial navicular, & the medial calcaneus.

5/ It contains (from anterior to posterior):

“TOM” - the tibialis posterior (TP) tendon,

“DICK” - the flexor digitorum longus (FDL) tendon,

“&” - the TN neurovascular bundle,

“HARRY” - the flexor hallucis longus (FHL) tendon.

6/ The TN gives off the medial calcaneal nerve (MCN) just prior to entering the tunnel,

and splits within/soon after exiting the tunnel to form the lateral plantar nerve (LPN), medial plantar nerve (MPN), & Inferior Calcaneal Nerve (ICN).

👉* Remember ICN & MPN *👈

7/ Methods of entrapment:

• ankle DF & Eversion

• history of foot/ankle fracture/dislocation

• pronated foot

• edematous conditions

These conditions could create a tension entrapment at the distal end of the tunnel.

8/ What you *could* find in the clinic w/ TT Entrapment:

• local and radiating symptoms with palpation of the tunnel

• weak flexion of toes

• weak big toe aBDuction (secondary effect)

• sensory changes along sole of foot (burning pain, tingling, numbness)

9/ So, why point out the MPN & ICN earlier?

Think back to people with sharp pain in the yellow circle marked below.

Yeah...

That’s right... “PLANTAR FASCIITIS” could be neurogenic!!!

10/ In some cases of “plantar fasciitis” folks end up “failing” conservative treatments because nobody took the time to check for neurogenic causes of their pains!

11/ Let’s move on to a less common TN entrapment site...

Entrapment at Proximal Soleus (called the Soleus Sling Syndrome) occurs where it passes through a tunnel between the superficial and deep posterior compartments of the leg at the origin of the soleus muscle.

12/ SSS presents with:

• pain in the popliteal fossa and proximal calf (aggravated by active and passive dorsiflexion of the foot)
• inability to bear weight
• weakness of toe flexion
• sensory deficits on the sole of the foot

All of which are aggravated by walking.

13/ Clinical note:

People reporting of persistent posterior leg “tightness” should be checked for neurogenic involvement.

For these folks, stretching doesn’t help, but they can’t stop stretching their hamstrings/calves!

Think: repetitive hamstring tears, calf strains, etc.

14/ Common conservative treatment strategies?

• orthotics
• address pathomechanics involved with foot pronation & excessive hind foot eversion
• check shoes
• check running form & walking mechanics
• check hip mobility

15/ IF full trials of conservative strategies fail, then neurolysis may be indicated.

Better evaluation begets better treatment strategies.

Like a mentor of mine once said:

“If you aren’t looking for it, then you won’t see it.”

Extra: apparently bone flutes can still be purchased in Europe...

trinoxsamoni-lutherie.com/products/bone-…