Summary
Highlights
This lesson provides a specific view of the bones of the lower limbs, which include the bones of the lower limb girdle and the lower limb itself. It is part of a playlist on the skeletal system.
The pelvic girdle is formed by two hip bones, also called iliac bones. Each iliac bone is composed of three individual bones: the ilium (the largest), the pubis (anterior), and the ischium (posterior). Therefore, there are two ilia, two pubes, and two ischia.
The main bone of the thigh, and the largest bone in the body, is the femur. This long bone articulates with the iliac bone (hip bone) through its rounded head. The thigh consists of a single bone, the femur.
In the knee region, there is a sesamoid bone, the largest sesamoid bone in the body, called the patella. The patella is inserted into a tendon from the quadriceps femoris muscles, which then inserts into the tibia.
Unlike the thigh, the leg (or shin) is formed by two bones: the tibia and the fibula. In anatomical position, the tibia is located medially, is larger and thicker, while the fibula is thinner and located laterally. A mnemonic is 'fibula is thin and goes out' (fina e fica fora).
The foot is composed of 26 bones: seven tarsal bones, five metatarsal bones, and 14 phalanges. The tarsal bones are small, short bones in the hindfoot. The metatarsal bones are long bones leading to the toes, and the phalanges are the bones of the toes themselves.
The tarsal bones include: the talus (most superior, articulates with the tibia at the ankle), the calcaneus (inferior to the talus, the largest tarsal bone, forming the heel), the navicular (anterior to the talus), three cuneiform bones (medial, intermediate, and lateral, anterior to the navicular), and the cuboid (most lateral, anterior to the calcaneus).
There are five metatarsal bones, numbered from 1 to 5, starting from the hallux (big toe) towards the little toe. These are the first, second, third, fourth, and fifth metatarsals.
The phalanges are the bones of the toes. All toes, except the hallux, have three phalanges: proximal, middle, and distal. The hallux (big toe) has only two phalanges: proximal and distal. These are named based on their proximity to the limb's origin.
The foot is divided into regions: the retrofoot (talus and calcaneus), the midfoot (navicular, cuneiforms, and cuboid), and the forefoot (metatarsals and phalanges). Additionally, two small sesamoid bones, medial and lateral, are found below the head of the first metatarsal.
The video concludes by reiterating the main bones of the lower limbs: pelvic girdle (ilium, pubis, ischium), thigh (femur), leg (tibia, fibula, patella), and foot (tarsals, metatarsals, phalanges). It emphasizes the importance of anatomical position for understanding bone locations and encourages viewers to like, subscribe, and enable notifications for more content.