hello anatomy colleagues and welcome to the last lecture video for the musculoskeletal
portion of the course and we are going to discuss the muscles of the foot we will find
some similarities to what we saw in the hand we will have lumbricals and interracial eye kind of
bouncing back but i want to start with some fascia that's actually located in this region because
really the major role of the foot muscles and the fascia in this region are protection and to
support support all that weight of the body and because of that we have a fairly robust region
on the plantar surface or the sole of the foot region of fascia so plantar fascia is just the
deep fascia of the foot and it's going to have this really thick central part that you can see
right here and this is often referred to as plantar aponeurosis the more medial and lateral
portions of the plantar fascia they're robust but not nearly as robust as what you have in
the central part and what you're going to see are these really longitudinally arranged bundles of
dense fibrous connective tissue and really this fascia is holding the parts of the foot together
it is going to function as a superficial ligament it will protect the soul from injury
and it will importantly help support the longitudinal arches of the foot
you can see it extending from the calcaneus and then there will be these small kind of digital
slips of plantar aponeurosis that will extend up to the digits now if you have a tearing or kind of
inflammation in this region that is referred to as plantar fasciitis oftentimes plantar fasciitis can
just be relieved by not using that area quite as much kind of keeping off that region but in
certain cases sometimes you will have to have some type of surgical intervention to to correct that
now the 20 intrinsic muscles of the foot meaning that they have both their proximal and distal
attachments on the foot region 14 of those muscles are going to be located on the planter side
two are on the dorsal side and four are kind of intermediate and despite these being separated
particularly on the plantar side despite these being separated into compartments they're really
playing small synergistic roles and other actions and their primary function is going to be to work
as a group during the support phase of stance so really maintaining those arches of the foot
and really there's less importance for these muscles of the foot uh in their their individual
individual um actions as fine control of the individual toes is not as important for most
people as what we had in the hand so we're going to kind of talk big picture things with these
muscles and less about each individual muscle like we did with the hand region so when we're talking
about the plantar side the majority of these will play some role in terms of flexion of the digits
particularly when we're talking about flexor hallucis brevis flexor digital minimie brevis
you will even have a flexor digitorum brevis and then you will have some muscles that will play a
role in terms of abduction and or abduction and adduction in these regions right here
you do have lumbricals and interossei associated with the foot like we had with the hand the
lumbricals are going to have similar to what we had in the hand a proximal attachment on
tendons and specifically it will be the flexor digitorum longus tendons and then you will have
them inserting into the extensor expansions so these will flex the metatarsophalangeal
or mp joints and then extend the toes or those endophalangeal joints of two through
five so the reason is crossing right here it can play a role with flexion but then the
fact that they are attaching on the extensor expansions mean that they can extend the toes
we have both dorsal and plantar not palmer but plantar interossei
when we're talking about the foot it shares the similar actions with the lumbricals with
flexion of those mp joints and extension of the toes but similar to what we had in the hand they
will also play a role in terms of abduction and adduction and when we're talking about which
digit from which the other digits are abducting or adducting it is the second digit not the third
like we had in the hand so those dorsal interossei will a b duct so move away from the second digit
whereas the and i have palmer here oh my goodness i totally messed up right at the end dang planter
so those planter interossei will a deduct or move towards the second digit
now the reason that we don't have an interossei right here on the first digit is that it is going
to have its own individual muscle that will play a role in terms of adduction
so it's really going to only you only have the plantar interossei on digits 3 through 5 and those
would adduct or move towards the second digit okay so hopefully um this is a review because we
have similar actions in the hand and the feet but when we're talking about libertals and interracial
we know that they share two sets of actions in common uh when we're specifically talking
about the toes or the foot region one is going to be extension of toes or the interphalangeal
digit or joints of two through five what is the other action that the lumbricals and interracial
share in common is it abduction of the first digit adduction of digits two through five flexion of
the mp joints two through five flexion of the toes or extension of the mp joints two through five
so we know that we're not looking um we shouldn't really be looking so much at the interphalangeal
joints because right here it is telling us that we know that these share extension
of the interphalangeal joints of two through five so flexion is not going
to be the answer here they're not going to be antagonistic to its to each other
um abduction of the first digit we don't need to worry about first digit when we're talking
about lumbricals and interossei we have other muscles that are going to play a role there
the um when we look over here we know that the plantar are going to a deduct digits 2 through 5
but the lumbricals don't also do that so that is not a shared action and so that leaves these two
so we're focused on those metatarsophalangeal joints or the mp joints and do they flex or do
they extend well they do not extend they will flex the mp joints and that has a lot to do with their
placement in terms of where they're going to cross that joint they will flex the mp joints but extend
the ip joints due to the attachments on the extensor expansions all right
that is it congratulations for making it through the musculoskeletal component of the lectures as
well as the laboratories you've done an amazing job you've learned ever so much i i know sometimes
it can seem a bit overwhelming but as we kind of review this material and continually review it and
ask questions often and early that will be the keys to success for this report or this portion
of the course as always please feel free to reach out to me with any questions and i thank you for
your time and attention throughout the course and i hope you have an amazing rest of your day