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Let's tackle the tibial nerve, sometimes called

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the posterior tibial nerve.

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And we begin with a mnemonic.

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We've got our friends Tom, Dick, and

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there's Harry with Harry's muscle.

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Tibialis posterior, the flexor digitorum,

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and the flexor hallucis.

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But we also have Tom, Dick,

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and very nervous Harry.

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Very standing for vascular, we've got arteries and

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veins kind of mush-moshed together, and then here's

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nervous Harry, the nerve, and then there's Harry.

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So Tom, Dick, and very

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vascular, nervous nerve, Harry.

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Let's scroll and follow our nerve.

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There's our nerve.

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We're going up, now we're going down.

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And our nerve is splitting into two nerves.

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Let's blow it up a little bit.

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It's a little bit tricky to

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do online, but we can do it.

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Let's make it a little bit bigger.

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We've got two nerves now.

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The one in the front is the medial plantar nerve.

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It's also going to be, as we'll see in

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the coronal projection, a little higher up

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than the lateral plantar nerve.

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But that'll be a story for another day.

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So the medial plantar nerve crosses the lateral

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surface of the posterior tibial artery.

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So here's the posterior tibial artery.

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Here's its lateral surface right there.

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That's lateral.

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That's medial.

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There is the medial plantar nerve.

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We've got some veins kind of making a soup in the neighborhood.

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It will then cross anterior to a branch

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of the artery called the medial plantar artery.

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And then it courses proximally between the

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quadratus plantae and the abductor hallucis.

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And we're going to show you that

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in the more advanced sections.

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But right now I'd like you to follow

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the medial plantar nerve down.

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And you can see, here's the abductor hallucis,

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and if we followed it more distally, there's

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our quadratus plantae, so it is between the two,

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just as we have advertised, but you're

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going to appreciate that a lot better in the

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coronal projection and more advanced discussions.

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Distally, it's still going to be located

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between these two structures, the quadratus plantae

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and the abductor hallucis.

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And then it lies in very close proximity

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to something called Henry's master knot.

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So, let's go back up again to find it.

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There it is, medial plantar nerve.

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What's Henry's master knot, you say?

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It's where the flexor digitorum and flexor

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hallucis come together to form this knot.

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There's the knot, and there

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is your medial plantar nerve.

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Find the knot, find the nerve.

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More distally, it's going to course along

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the medial border of the flexor digitorum brevis muscle,

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which is this one down here.

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And we'll have to show you that in

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the coronal projection on another day.

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And then we'll divide that nerve into

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articular, muscular, and cutaneous branches.

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The articular branches supply the articulations

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of the tarsus and the metatarsus regions.

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The muscular supply is pretty broad.

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The abductor hallucis, which we see here.

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The flexor digitorum brevis, the flexor hallucis brevis,

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Also at the base of the first metatarsal bone,

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it will itself divide into

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medial and lateral terminal branches.

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And that will also be a story for another day.

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It provides medial plantar cutaneous sensation

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to the big toe.

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Remember, it's on the plantar side.

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On the dorsal aspect of the big toe

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between the big toe and the second toe,

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it's the deep peroneal nerve

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that's responsible for the sensory supply.

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The terminal lateral branch will pass along

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the border of the flexor digitorum brevis

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muscle, and becomes more superficial.

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And then it divides into some digital branches.

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And again, that's probably a little

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too advanced for us to discuss today.

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So the medial plantar nerve may become

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compressed as it passes deep to its

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retinaculum adjacent to Henry's master knot.

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So if we look at Henry's master knot,

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which is where these two come together.

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There's our medial plantar nerve,

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then we follow it down.

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There's Henry's master knot and right as it

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starts to course around Henry's master knot,

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it may get irritated, crushed, or compressed

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between it and the abductor hallucis,

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and this may lead to the syndrome or

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condition known as Jogger's Foot.