Lower Limb Anatomy PDF

Prof. Rasha I. Anwer The skeleton of the lower limb is made of: (1) The pelvic girdle: Consists of right and left hip bones which connect the lower limb with the axial skeleton (sacrum) posteriorly. (2) Proximal segment: Consists of one bone, the femur. (3) Middle segmen...

Prof. Rasha I. Anwer The skeleton of the lower limb is made of: (1) The pelvic girdle: Consists of right and left hip bones which connect the lower limb with the axial skeleton (sacrum) posteriorly. (2) Proximal segment: Consists of one bone, the femur. (3) Middle segment: Consists of two bones: a) Tibia: medially. b) Fibula: laterally. (4) Distal segment : Consists of : a) Tarsal bones: seven short bones. b) Metatarsal bones: five, named from medial to lateral. c) Phalanges: Fourteen, two for the big toe and three for each of the rest toes. HIP BONE THE HIP BONE  It is formed of three bones, which fuse in a Y-shaped epiphysis at the acetabulum (hip joint socket). These three bones are the ilium, superiorly, ischium posteroinferiorly and pubis anteroinferiorly.  The outer surface of the hip bone  The ilium: The outer (lateral) surface of the ilium is called the gluteal surface. This surface is limited superiorly by the iliac crest. It starts anteriorly at the anterior superior iliac spine and ends posteriorly in the posterior superior iliac spine. A marked projection on the outer lip of the iliac crest called iliac tubercle lies about two inches behind the anterior superior iliac spine.  The anterior inferior iliac spine and posterior inferior iliac spine.  The outer (gluteal) surface of the ilium is characterized by the presence of three curved gluteal lines, the posterior gluteal line, the anterior gluteal line and the inferior gluteal line.  Ischium, ramus, ischial tuberosity and ischial spine HIP BONE Ischial tuberosity: It is divided by a transverse ridge into upper and lower areas.  The upper area is divided again by oblique line into: a) An upper lateral part which provides origin for the semimembranous muscle. b) A lower medial part which provides origin for the long head of the biceps femoris and semitendinosus muscle. The lower area is divided by vertical line into: a) A lateral part which provides origin for the ischial head of the adductor magnus. b) A medial part which can be felt subcutaneously. It is the part which supporting the body weight in sitting position. The pubis: It is divides into a body, superior ramus and inferior ramus. The body of the pubis has an upper rounded border called the pubic crest. It ends laterally in a projection called the pubic tubercle. The obturator foramen : The acetabulum :  Identification of side:  The lateral side is identified by the acetabulum.  Superiorly, marked by the flat ilium with its curved border called iliac crest.  Anteriorly and inferiorly, there is the pubis and the obturator foramen. THE FEMUR  The femur is the bone of the thigh. It is made of a shaft, an upper and lower ends.  The Upper End It is made up of, the head, neck, a lesser and greater trochanter.  The head: forms about two-thirds of a sphere and articulates with the acetabulum of the hip bone to form the hip joint. It is directed medially and upwards. In the center of the head there is a small depression called the fovea capitis, for the attachment of the ligament of the head (ligamentum teres).  The neck of the femur: forms with the shaft an angle of about 125o.  The greater trochanter: is a prominent large projection found at the upper part of the junction between the neck and shaft.  The lesser trochanter: is a small conical projection at the junction between the shaft and the postero-inferior part of the neck.  Intertrochanteric line:  Intertrochanteric crest:  The Shaft:  The anterior surface of the shaft of the femur is smooth, rounded and shows a general forward convexity. Its posterior surface is characterized by the presence of a sharp ridge called the linea aspera. This ridge has medial and lateral lips.  The inter-trochanteric line slopes across the front of the neck and shaft at their junction, and continues down below the lesser trochanter as a spiral line that runs into the medial lip of the linea aspera.  On the posterior aspect of the shaft below the greater trochanter there is a rough vertical ridge called the gluteal tuberosity.  Medial and lateral supracondylar lines.  Popliteal surface:  THE LOWER END  The lower end of the femur is made up of lateral and medial condyles. The two condyles are fused anteriorly. They are separated posteriorly by a deep intercondylar fossa. Above the lateral and medial condyls are the lateral and medial epicondyles respectively. The adductor tubercle is continuous with the medial epicondyle. Identification of side: The rounded head marks the upper end. The head is directed to the medial side. The shaft is convex anteriorly. The posterior surface is indicated by a longitudinal ridge in posterior surface of the shaft called linea aspera and by the intercondylar fossa in the lower end.  PATELLA  It is sesamoid bone present in the tendon of the quadriceps femoris muscle. It is a palpable triangular bone. It has an anterior and posterior surfaces, an upper, medial and lateral borders and an apex TIBIA  It is the medial large weight-bearing bone of the leg.  It articulates above with the condyles of the femur and head of the fibula and below with the talus and lower end of fibula.  It is a long bone having 2 ends and shaft.  Upper end: it has:  Two condyles: Large oval medial condyle and small circular lateral condyle.  Intercondylar area: Intercondylar eminence, anterior and posterior intercondylar areas.  Tibial tuberosity.  Lower end: has 5 surfaces:  Anterior: smooth.  Posterior: has groove for tendon of tibialis posterior.  Medial: elongated downward as medial malleolus.  Lateral: has notch for articulation with the lower end of fibula.  Inferior: articulates with the talus to form the ankle joint.  Shaft: has 3 borders and 3 surfaces.  Borders: anterior (shin of tibia), medial and lateral (interosseous).  Surfaces: posterior, medial and lateral. The posterior surface shows oblique line called soleal line dividing it into upper and lower parts.  Then a vertical line extends downward from the middle of the soleal line dividing the lower part into it into medial and lateral areas.  Subcutaneous parts of the tibia: 1. The 2 condyles. 2. Tibial tuberosity. 3. Anterior and medial borders. 4. Medial surface.  Side of the tibia: put the tibia in the following position to know its side:  The broad upper end is directed upward.  The medial malleolus is below and medial.  The tibial tuberosity is anterior.  FIBULA  It is the lateral bone of the leg.  It shares in ankle joint formation but doesn't share in the knee joint.  It has no role in transmission of the body weight to the ground.  It is long bone having 2 ends and shaft.  Upper end: It has head and neck. The head shows styloid process and facet for articulation with the lateral condyle of the tibia.  Lower end: It forms the lateral malleolus (subcutaneous triangular area).  It shows facet for articulation with the talus and malleolar fossa (behind the facet).  It shows groove for tendon of peronei (longus and brevis) muscles.  Shaft: has 3 borders and 3 surfaces:  Borders: 3 borders; anterior, posterior and medial (interosseous).  Surfaces:  Anterior (the smaller): between the anterior and medial borders.  Lateral (the larger): between the anterior and posterior borders.  Posterior: has median crest, which divides it into 2 areas.  Identification of the side: BONES OF THE FOOT  The foot is formed of tarsal bones, metatarsal bones and phalanges.  The tarsal bones are 7 in number. They are the talus, calcaneus, cuboid, navicular and 3 cuneiform (medial, intermediate and lateral).  The metatarsal bones are 5 in number. They are arranged 1st– 5th from medial to lateral.  The phalanges are 3 in each toe except the big toe has 2 phalanges.  Important joints of the foot include :the ankle joint (between the talus and both tibia and fibula), Subtalar joint (between the talus and calcaneus), Metatarsophalangeal joints and interphalangeal joints.  phalanges metatarsals cuneiforms navicular cuboid talus calcaneous