Bones of the Lower Limb PDF

Mrs Sichela  List the bones of the lower limb (pelvic girdle, thigh, leg, and foot bones). Describe the structure, relationships and function of the lower limb bones. Identify the surface anatomy of the lower limb bones. Describe the arches of the foot.  The lower limb is divided into the...

Mrs Sichela  List the bones of the lower limb (pelvic girdle, thigh, leg, and foot bones). Describe the structure, relationships and function of the lower limb bones. Identify the surface anatomy of the lower limb bones. Describe the arches of the foot.  The lower limb is divided into the gluteal region, thigh, leg, and foot on the basis of major joints, component bones, and superficial landmarks: The gluteal region:  is posterolateral and between the iliac crest and the fold of skin (gluteal fold) that defines the lower limit of the buttocks; The thigh:  Anteriorly, the thigh is between the inguinal ligament and the knee joint-the hip joint is just inferior to the middle third of the inguinal ligament  The posterior thigh is between the gluteal fold and the knee; The leg:  is between the knee and ankle joint; The foot:  is distal to the ankle joint. 1. Support the body weight 2. Locomotion  The thigh is the region of the lower limb that is approximately between the hip and knee joints:  anteriorly, it is separated from the abdominal wall by the inguinal ligament;  posteriorly, it is separated from the gluteal region by the gluteal fold superficially, and by the inferior margins of the gluteus maximus and quadratus femoris on deeper planes. The thigh is divided into three compartments:  the anterior compartment of thigh contains muscles that mainly extend the leg at the knee joint; innervated by femoral nerve  the posterior compartment of thigh contains muscles that mainly extend the thigh at the hip joint and flex the leg at the knee joint; Innervated by sciatic nerve  the medial compartment of thigh consists of muscles that mainly adduct the thigh at the hip joint. These are innervated by obturator nerve  The major artery, vein, and lymphatic channels enter the thigh anterior to the pelvic bone and pass through the femoral triangle inferior to the inguinal ligament.  Vessels and nerves passing between the thigh and leg pass through the popliteal fossa posterior to the knee joint.  Each lower limb = 30 bones femur and patella within the thigh tibia & fibula within the leg tarsal bones in the foot metatarsals within the forefoot phalanges in the toes Joints hip, knee, ankle proximal & distal tibiofibular metatarsophalangeal  longest & strongest bone in body head articulates with acetabulum (attached by ligament of head of femur) Fovea capitis neck is common fracture site greater & lesser trochanters, linea aspera, & gluteal tuberosity-- muscle attachments Adductor tubercle - - adductor magnus medial & lateral condyles articulate with tibia patellar surface anteriorly between condyles intercondylar fossa - depression between the condyles Angle of inclination Normal range 115°- 140° Male > Female Proximal femur Anterior and medial views Posterior and lateral views  Largest sesamoid bone in the body Forms the patellofemoral joint Superior surface is the base Inferior, narrower surface is the apex Thick articular cartilage lines the posterior surface Increases the leverage of the quadriceps femoris muscle  Is the region of the lower limb between the knee and ankle joint  The leg contains two bones:  The tibia is medial in position, is larger than the laterally positioned fibula, and is the weight-bearing bone  The fibula does not take part in the knee joint and forms only the most lateral part of the ankle joint-proximally, it forms a small synovial joint (superior tibiofibular joint) with the head of the tibia.  The tibia and fibula are linked along their lengths by an interosseous membrane, and at their distal ends by a fibrous inferior tibiofibular joint  The distal tibia and fibula together with the one of the tarsal bones of the foot (talus) form the ankle joint Tibia medial & larger bone of leg weight‐bearing bone lateral & medial condyles Intercondylar eminence tibial tuberosity for patellar lig. proximal tibiofibular joint medial malleolus at ankle fibular notch Fibula not part of knee joint muscle attachment only Head, neck, shaft lateral malleolus at ankle Bones  There are three groups of bones in the foot:  the seven tarsal bones, which form the skeletal framework for the ankle;  metatarsals (I to V), which are the bones of the metatarsus;  the phalanges, which are the bones of the toes-each toe has three phalanges, except for the great toe, which has two.  Makes up the posterior half of the foot  Contains seven bones called tarsals  The tarsal bones are arranged in a proximal group and a distal group with an intermediate bone between the two groups on the medial side of the foot  The proximal group consists of two large bones, the talus (Latin for ankle) and the calcaneus (Latin for heel): The talus  Is the most superior bone of the foot and sits on top of and is supported by the calcaneus  It has a rounded head, which is projected forward and medially at the end of a short broad neck, which is connected posteriorly to an expanded body.  It is considered as the cornerstone of the medial longitudinal arch of the foot.  One peculiar feature of talus is that it has no muscular attachments  Articulations  It articulates above with the tibia and fibula to form the ankle joint  Articulates with the intermediate tarsal bone (navicular) on the medial side of the foot  Artculates inferiorly with the calcaneaus The calcaneus  is the largest of the tarsal bones-  posteriorly it forms the bony framework of the heel and anteriorly projects forward to articulate with one of the distal group of tarsal bones (cuboid) on the lateral side of the foot. Superior, inferior and lateral view  The intermediate tarsal bone on the medial side of the foot is the navicular (boat shaped)  This bone articulates behind with the talus and articulates in front and on the lateral side with the distal group of tarsal bones.  One distinctive feature of the navicular is a prominent rounded tuberosity for the attachment of the tibialis posterior tendon, which projects inferiorly on the medial side of the plantar surface of the bone.  From lateral to medial, the distal group of tarsal bones consists of  The cuboid (Greek for cube), which articulates behind with the calcaneus and in front with the bases of the lateral two metatarsals  Three cuneiforms (Latin for wedge)-the lateral, intermediate, and medial cuneiform bones articulate behind with the navicular bone and in front with the bases of the medial three metatarsals.   Consists of five small long bones called  metatarsals  Numbered 1–5 beginning with the hallux (great toe)  First metatarsal supports body weight  14 phalanges of the toes  Smaller and less nimble than those of the fingers  Structure and arrangement are similar to phalanges of fingers  Except for the great toe, each toe has three phalanges  Proximal, middle, and distal  The bones of the foot do not lie in a horizontal plane.  Instead, they form longitudinal and transverse arches relative to the ground  The arches of the foot are present from birth.  Due to the presence of subcutaneous fat the arching is not apparent during infancy and childhood.  Gradually, the plantar surface acquires the concave appearance and the characteristic footprint is evolved. Function  distribute body weight over foot  yield & spring back when weight is lifted  Found along each side of foot Lateral longitudinal arch Medial longitudinal arch  Calcaneum, cuboid, and lateral 2 metatarsals  Calcaneum, talus, navicular, cuniforms, and medial 3  This arch is short, almost metatarsals touching the ground  Transverse arch across midfoot region  Cuboid, cuneiforms & bases of metatarsals  Ligaments and muscles support the arches of the foot:  Ligaments that support the arches include the plantar calcaneonavicular, plantar calcaneocuboid, and long plantar ligaments, and the plantar aponeurosis;  Muscles that provide dynamic support for the arches during walking include the tibialis anterior and posterior, and the fibularis longus.  Pes Planus/Flatfoot  is due to collapse of medial longitudinal arch. Pes cavus/Clawfoot  highly arched foot The hallux valgus  refers to the deformity in which the big toe or hallux deviates laterally  there is abnormal prominence of the head of first metatarsal bone on the medial side of the foot, just behind the big toe.  There is collapse of the transverse arch due to varus position of first metatarsal bone. Pes planus/flat foot Pes cavus/clawfoot Hallux valgus Clubfoot.  There are different types of talipes.  Talipes equinus: the foot is plantarflexed and the person walks on toes (like a horse).  Talipes calcaneus: the foot is dorsiflexed and the person walks on heel. In talipes varus the foot is inverted and the person walks on lateral margin of foot.  Talipes valgus: the foot is everted and the person walks on medial margin of foot.  Talipes equinovarus deformity, the foot is held in plantarflexed and inverted position