Pelvic Girdle Formed by 2 hip bones (ossa coxae). These are large and heavy bones attached securely to the axial skeleton. The sockets (Acetabulums) that connect the thigh bones are deep and heavily reinforced by ligaments. Most important function is: bearing the total weight of the upper body. Reproductive organs, urinary bladder, and parts of the large intestine lie within.
Hip Bones Each hip bone is formed by the fusion of 3 bones: ilium, ischium, and the pubis. Ilium- forms most of hip bone. When you rest your hands on your hips they are on your alae (wing like projection) –Iliac crest important for intramuscular injection sites.
Hip Bones Ischium- sit down bone –Greater sciatic notch: allows blood and the large sciatic nerve to pass from pelvis to thigh. Buttocks Injections should be far away from here. Pubis- pubic bone –Obturator foramen: opening that allows blood vessels and nerves to pass into anterior thigh. –Pubic Symphysis: Pubic bones of each hip fuse to form cartilaginous joint
Comparison of Male and Female Pelvic Structure CharacteristicFemaleMale Bone thicknessLighter, thinner, and smoother Heavier, thicker, and more prominent markings Pubic arch/angle80˚–90˚50˚–60˚ AcetabulaSmall; farther apartLarge; closer together Sacrum Wider, shorter; sacral curvature is accentuated Narrow, longer; sacral promontory more ventral CoccyxMore movable; straighter Less movable; curves ventrally
Image from Table 7.4 Comparison of Male and Female Pelvic Structure Female Male
Thigh Femur- heaviest and strongest bone Neck of femur is a common fracture site, especially in old age. Head of femur articulates with the acetabulum of the hip bone
Leg bones Two bones: Tibia and Fibia Connected by interosseous membrane Tibia= shinbone, larger and more medial –Medial and lateral condyles articulate with femur. –Kneecap ligaments attach to tibial tuberosity Fibula –Takes no part in forming the knee joint. –Lateral malleous forms outer part of ankle
Foot Composed of: tarsals, metatarsals, and phalanges. 2 important functions: –Support our weight –Propel our bodies forward when we walk or run.
Bones of feet Tarsals- ankle bones –7 bones total Metatarsals- soles of the foot –5 total Phalanges- bones of the toes –14 total (3 per toe except for the greater toe which only has 2)
Tarsals Body weight is carried mostly by the two largest: Calcaneus (heel bone) and talus (ankle bone) Last 5 are: Navicular, medial cuneiform, intermediate cuneiform, lateral cuneiform, and cuboid.
Arches of Foot 3 strong arches: 2 longitudinal and 1 transverse. Ligaments which connect foot bones and tendons of foot muscles help hold foot bones firmly in arched position. Weak arches= fallen arches or flat feet