Appendicular Skeleton Pelvic Girdle & Lower Extremity

Pelvic Girdle Made up of 2 Ossa Coxae Articulated anteriorly by the symphysis pubis Articulate posteriorly to the sacrum @ the Sacroiliac Joint Each Ossa Coxae is made up of 3 separate bones that are fused together: Ilium, Ischium & Pubis The Pelvic Girdle Functions Muscle Attachment Protection of Pelvic Organs Supports the weight5 of the spine & trunk, & transfers weight to the lower extremity Pelvic Girdle

Ossa Coxae: The Ilium, Ischium & Pubis ossify in the acetabulum (hip socket) Ilium: Uppermost & largest portion * Iliac Crest Ischium: Posterior, Inferior Portion * Ischial Tuberosity Pubis: Anterior, Inferior Portion * Symphysis Pubis

Ossa Coxae: Anterior View

Pelvic Girdle (pink) Greater Pelvis (False Pelvis): ASIS – ASIS Lesser Pelvis (True Pelvis): Ischial Spine – Ischial Spine Symphysis Pubis: fuses ossa coxae anteriorly & allows for widening of the birth canal Sacroiliac Joint: Where the sacrum & ilium articulate, axial skeleton & appendicular skeleton come together

Pelvis The pelvis as a whole is made up of : 2 Ossa Coxae Sacrum Coccyx

Femur Longest, Heaviest, & Strongest bone in the body Bony Landmarks Femoral Head: articulates with the acetabulum Femoral Neck: between the Intertrochanteric Line & Femoral Head Greater Trochanter: Proximal & Lateral Lesser Trochanter: Medial & Inferior Intertrochanteric Line: runs between the greater trochanter & lesser trochanter Medial Epicondyle: above the articular surface & place of attachment for the Medial Collateral Ligament (MCL) Medial Condyle: surface that articulates with the tibia Lateral Epicondyle: above the articular surface & place of attachment for the Lateral Collateral Ligament (LCL) Lateral Condyle: surface that articulates with the tibia Femur

Patella Triagular in shape The patella helps protect the knee & strengthens the quadriceps muscle group Sesamoid Bone Sesamoid bones are found in tendons that pass over joints. The bone is imbedded in the tendon to increase mechanical effect & keep tendon from being caught in the joint Bony Landmarks Base: superior Apex: inferior, point Articular Surface: smooth surface on posterior side Patella

Sunrise View Patella rest in the trochlear groove Patella

Tibia Articulates with the femur (proximally) @ the knee & the talus (distally) @ the ankle. The tibia is the primary weight bearing bone in the lower leg. Bony Landmarks Intercondylar Eminence: Anterior Cruciate Ligament (ACL) attachment Medial Condyle: Femoral articulation Medial Epicondyle: MCL attachment Lateral Condyle: Femoral articulation Lateral Epicondyle: LCL attachment Tibial Tuberosity: attachment for patellar tendon Medial Malleolus: ankle stabilization (Mortise) Tibia

Fibula Fibula Bony Landmarks Articulates proximally & distally with the tibia. The Fibula bears only about 10% of an adults body weight. Bony Landmarks Fibular Head: articulates with the tibia proximally Lateral Malleolus: ankle stabilization (Mortise) Syndesmosis: distal tibiofibular joint Fibula

Tarsal Bones Seven Tarsal Bones Talus: articulates with the tibia & fibula to comprise mortise of ankle Calcaneus: Largest tarsal bone, forms heel & is where achilles tendon attaches Navicular: anterior to calcaneus, on medial side, block shaped Medial Cuneiform Intermediate Cuneiform Lateral Cuneiform Cuboid: the most lateral tarsal bone, borders the navicular & lateral cuneiform Tarsal Bones

Metatarsals 5 metatarsals in each foot Weight bearing bones Metatarsals are numbered 1-5 medial to lateral 1st metatarsal is the largest b/c it supports the most body weight & is the last stop in ambulation 2 sesamoid bones are found under the 1st metatarsal Each metatarsal has a: Base: tarsometatarsal joint Body: middle Head: metatarsophalangeal joint, ball of foot (1st & 2nd head) Metatarsals

Longitudinal Arch Transverse Arch Arches of Foot

Phalanges 14 phalanx bones in each foot The phalanges are numbered 1-5, medial to lateral Great Toe (phalange #1) has 2 phalanx bones Proximal Phalanx Distal Phalanx Phalanges #2 - #5 have 3 phalanx bones each Middle Phalanx Phalanges