at layer 1, there are really three muscles
that I want to make you aware of. We have
abductor hallucis, flexor digitorum brevis,
and abductor digiti minimi. So, if we look here,
we can go abductor hallucis passing
along the medial aspect of the foot, and then
we have abductor digiti minimi passing along
the lateral aspect of the foot. And then most
centrally, we have flexor digitorum brevis.
So these muscles within the most superficial
layer 1 of the foot. All of these three muscles
share a common origin. They all originate
from the calcaneus, specifically, the tuberosity
of the calcaneus, and from the plantar aponeurosis.
As you can see, they have different functions.
Therefore, they insert onto different regions
of the foot. Abductor hallucis inserts into the
base of the proximal phalanx of the great toe.
Flexor digitorum brevis inserts into
the middle phalanges of digits 2 to 5.
And abductor digiti minimi attaches to the base
of the proximal phalanx of the fifth digit.
So we can see they have a common origin, but
depending on their function, they have a
different insertion. All of these muscles are going
to be supplied by either the medial or the
lateral plantar nerve. And the medial and
the lateral plantar nerve have divided from
the tibial nerve. The medial plantar nerve
is going to supply abductor hallucis and flexor
digitorum brevis, whereas, the lateral plantar
nerve is going to supply abductor digiti minimi.
As the name suggests, it can lead on to the
function. So abductor hallucis is going to
abduct, and it also can flex the great toe,
the first digit. Flexor digitorum brevis is
going to flex digits 2 to 5. And abductor
digiti minimi is going to abduct, and it can
also flex the fifth digit. So if we now move
on to layer 2, we can see that we’ve had