Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Lower Extremities Function of Lower Limbs • The lower limbs carry our total body weight when we are upright. • Compared to the upper limbs, they are stronger and thicker. Attachment • The lower limbs are attached to the vertebrae at the coxal bones (AKA hip bones) • The coxal bones articulate with the sacrum posteriorly, and anteriorly, they are held together with fibrocartilage. The Coxal Bones • Three fused bones per side of the body • Commonly called the “hip bones” • Together with the sacrum and coccyx, they form the pelvic girdle. • Although the suture lines are hard to find, each coxal bone is formed by the fusion of 3 different bones: – The ilium – The ishium – The pubis The Ilium • It is a large broad bone that forms most of your hips. • The upper edge is the iliac crest and is an important anatomical landmark. • It connects posteriorly with the sacrum at the sacroiliac joint. The Ischium • AKA the “sitdown bone” • The most inferior portion of the coxal bones. • Has a rounded, rough curve that is actually what we sit on. • Has a small projection called the ischial spine that is an important landmark, esp in pregnant women. • If the spine is too large or long, it can interfere with the delivery during birth. The Pubis • The most anterior part of the coxal bones. • Fuses the 2 coxal bones ateriorly at a cartilaginous joint called the pubis symphysis. • This joint is flexible and in women, it is what allows the pelvis to widen and accommodate the developing fetus. The Socket • The ilium, the ishium, and the pubis all meet and fuse at the socket called the acetabulum. • This deep socket is where the head of the femur will attach to the pelvis. The True v False Pelvis • The pelvis is divided into two major regions: – The false pelvis = the area from iliac crest to iliac crest. – The true pelvis = the inferior portion of the pelvis. This is the area that allows a child to pass during childbirth. False Pelvis True Pelvis The Male vs the Female Pelvis • The female has a larger pubic arch and is more circular • The female bones are thinner • The female ilium flare more laterally • The female sacrum is shorter and less curved Female Pelvis Male Pelvis The Femoral Region • Made up of one bone, the femur. • Is the heaviest and strongest bone of the human body. • The proximal head is ball-like and fits into the acetabulum of the pelvis. • The femur slants medially as it runs downward. • This brings the knees in line with the body’s center of gravity. Head Patellar surface • Distally, the femur has 2 knob-like areas: – The lateral condyle – The medial condyle • Both of these bones articulate with the tibia below. • Anteriorly, the distal femur has a smooth patellar surface where the patella joins to form the knee joint. Lateral condyle Patellar surface Medial condyle The Lower Leg • Made up of 2 bones: – The tibia – The fibula • Are connected with an interosseous membrane that hold the 2 bones together along their length. The Tibia • AKA the “shin bone” • The larger and more medial of the 2 lower leg bones. • The proximal end has medial and lateral condyles that articulate with the distal part of the femur at the knee. Lateral condyle Medial condyle The Tibia • The anterior surface of the tibia, the tibial crest is the sharp edge that is easily felt beneath the skin. • Has a distal protrusion that forms the inner part of the ankle called the medial malleolus. The Fibula • Is thin bone that lies lateral to the tibia. • Has no part in forming the knee joint. • Has a distal protrusion that forms the outer part of the ankle called the lateral malleolus. The Foot • Made up of 26 bones: – 7 tarsal bones – 5 metatarsal bones – 14 phalanges The foot bones are all held together with ligaments • Has 5 small and 2 large tarsal bones: – The calcaneus or the “heel bone” – The talus, sits inferior to and articulates with the tibia – The arch of the foot is made up the metatarsal bones. (numbered 1 – 5, medial to lateral) • The toes of the foot are the phalanges. (numbered 1 – 5, starting with the hallux) The End