Ok, and now it is time to finish up the muscular apparatus with the lower extremities. I hope you are learning some new good stuff about your body that will help you take good care of it.
Let's first print the labelling exercise sheets and the term list to follow along with the video.
Also, here are the lecture notes in multiple formats:
Lower Extremity Muscles (full pager)
Lower Extremity Muscles (2 per page)
Lower Extremity Muscles (3 per page)
And here are the videos:)
11.1 Many muscles originate from around the pelvis. One of them reaches from the sacrum to the greater trochanter. When it contracts, the femur gets pulled backwards, which rotates the foot outward. Can you name that muscles?
11.2. Another set anchor around the crest of the ilium on the external iliac fossa and reaches to the greater trochanter and even further down the thigh to the outside of the knee (via the IT band). Those muscles pull the leg outward as in abduction. Can you list the muscles that accomplish that?
11.3. In the front is a set of muscles that help us lift the thigh up. One of them originates from the anterior part of the lumbar spine; that’s deep! It’s cousin anchors into the front of the ilium; you can crab it with your fingers if you slide them in and downward along the crest of the ilium, starting at the ASIS. Do you know what muscle group I am describing?
11.4. Let’s now consider the muscles around a thigh. If we group them broadly, we can make out three sets: one in the front, the inside, and one in the back. The muscles in the back group mainly occupy themselves with bending the knee. Can you name them?
11.5. The group in the front of your thigh are the most powerful muscles in our body. They oppose the back muscle group’s action by straightening out the knee. These muscles are holding our body’s up right against gravity by keeping the knees from buckling. Can you name all the names of this muscle group?
11.6. Onward to the massive muscle group that concerns itself with pulling the thigh medial as in adduction. It makes up the thigh’s medial muscle group. They are strong lateral stabilizers that make sure we can stand, walk, and run without falling over - visualize yourself running zig-zag to understand their massive job. Can you name the muscles that make up this group?
11.7. Let’s move on to the calf muscles. Most significantly, in the back, are the 2 visible swellings that stand out when someone stands on their toes. These two superficial muscles have a third companion lying underneath that is part of the group. Together, they assure our body weight doesn’t collapse the ankle joint under gravity when we stand upright. Can you name those muscles?
11.8. Besides that superficial group, the deeper calf muscles can be grouped into three compartments: an anterior containing muscles that extend toes / dorsiflex the foot, a posterior one that mostly plantar flexes the foot & toes, and a lateral compartment filled with muscles significantly help evert the foot (bring the little toe up & out). Name the three muscles that dorsiflex.
11.9. Twisting an ankle strongly makes the sides of one’s calf achy and sore. That pain comes from the place where the muscles of the lateral compartment anchor into the fibula. Usually the most affected muscle is one that reaches behind the lateral malleolus and from there travels underneath the foot to attach on the underside of the longitudinal arch! Crazy, right? If you have twisted an ankle, there is a likelihood that digging your fingers deep into the medial foot underneath the arch is tender. What muscle am I describing?
11.10. The last muscle group lies deep posteriorly underneath the triceps surae. It’s three muscles attach on the tibia & fibula in the back and from there travel behind the medial malleolus, to then anchor into the medial arch, and underside of all the toes (including the hallux). Name the muscles that are the main plantar flexors.
Here are some samples of my in-class lecture. It's amateur and fully shot, edited, and uploaded using my iPhone. Have a peek.
Click here for a copy of the Anatomy Academy describing the lower extremities if you like to read about the muscles some more.