bones and joints of the lower limb

Pelvic girdle

what holds the lower limbs onto the rest of the body

pelvis

comprised of sacrum and both os coxa

sacroiliac joint

connects the sacrum and ilium; where our axial and appendicular skeletons meet

pubic symphysis

fibrocartilaginous joint that is the anterior meeting point of the two os coxa; what holds everything together

anterior superior iliac spine (ASIS)

bony projection on the ilium where ligaments and muscles attach.

pubic tubercles

the bony prominence on the superior part of the pubis; one on either side of the pubic symphysis

true pelvis

located below the pelvic brim; site of urogenital structures (ex. bladder)

false pelvis

located above the pelvic brim, supports gastrointestinal tract

sacral promontory

anteriormost point of the sacrum

plane of pelvic brim

inlet of the pelvis

anterior view of sacrum

smooth, part of axial skeleton

anterior sacral foramina

holes on the anterior side of sacrum

posterior view of sacrum

bumpy and rigid

sacral canal

site where nerves from the spinal cord enter the sacrum

posterior sacral foramina

holes on the posterior side of the sacrum; where spinal nerves exit the sacrum

median sacral crest

ridges on the back of the scrum

auricular surface

connection point between the sacrum and the os coxa; “ear”- shaped

os coxa

made of three bones that develop separately and fuse around ages 15-17

ilium

first bone and largest of ox coxa

ischium

second bone of os coxa, forms lower and back part of hip bone

pubis

third and smallest bone of os coxa

acetabulum

meeting point of all thre bones in the os coxa; “socket” part of the ball and socket hip joint; where head of femur sits

iliac spine

bony projections on the ilium

iliac fossa

the “scooped-out” area of the ilium if looking medially

ischial tuberosity

“sit bones”; rough surface on the bottom of the ischium where muscles attach

obturator foramen

opening between the pubis and ischium; where nerves, arteries, and veins pass through

greater sciatic notch

indentation in the ilium; passageway for sciatic nerve

lesser sciatic notch

indentation in the ischium; passageway for sciatic nerve

superior pubis of ramus

higher “branch” part of pubis

inferior ramus of pubis

lower “branch” part of pubis

lesser sciatic foramen

small opening located posteriorly in the pelvis; allow for nerves and vessels to move through to lower limb

greater sciatic foramen

larger opening located posteriorly in the pelvis and superiorly to the lesser sciatic foramen; allow for nerves and vessels to move through to lower limb

sacrotuberous ligament

runs from the sacrum to the ischial tuberosity

sacrospinous ligament

runs from the sacrum to the ischial spine

femoral head

uppermost part of the femur; “ball” of the hip’s ball and socket joint; always points medially

greater trochanter

lateral bony prominence at the top of the femur; sight of muscle attachments

lesser trochanter

medial bony prominence at the base of the femoral neck; sight of muscle attachments

intertrochanteric crest

ridge between neck and shaft of the femur; only present on posterior side

shaft

long portion of the femur; weight-bearing

patellar surface

smooth area at the bottom of the femur where the patella sits

lateral/medial femoral epicondyles

rough-textured areas on the bottom of the femur where muscles attach

lateral/medial femoral condyles

smooth areas on the bottom of the femur where bones interact

patella

sesamoid bone (embedded with tendons); helps to adjust the leverage of surrounding muscles

tendon

fibrous tissue that connects muscle to bone

ligament

fibrous tissue that connects bone to bone

base

top of the patella bone

apex

bottom of patella bone

quadricep tendon

tendon connecting the four quadriceps muscles to the patella; superior to patella

patellar ligament

ligament connecting the patella to the tibia

lateral/medial condyles of tibia

where the leg articulates with the femur

fibula

smaller, more lateral, non-weight-bearing bone in the leg

tibia

larger, more medial, weight-bearing bone in the leg

tibial tuberosity

where patellar ligament attaches

head of the fibula

where the fibula attaches to the tibia

lateral malleolus

lateral part of the “hammerhead” bottom of the leg

medial malleolus

medial part of the “hammerhead” bottom of the leg

leg bones

consists of tibia and fibula

talus

where fibula and tibia attach to the foot by grabbing onto either side

calcaneus

heel bone; where calcaneal (achilles) tendon attaches

navicular

“boat-shaped” bone; located medially between the talus and the cuneiform bones

cuboid

cube-shaped bone; located laterally between the calcaneus and the 4th and 5th metatarsals

cuneiform bones

three bones in the midfoot; includes the medial, intermediate, and lateral cuneiforms

metatarsals

group of five long bones in the midfoot

phalanges

14 bones that make up the toes of the foot; each digit consists of a proximal, middle, and distal phalanx (big toe missing middle)

knee joint

synovial, modified hinge joint that allows for flexion/extension, slight rotation and gliding

extracapsular ligament

outside the joint capsule

intracapsular ligament

inside the joint capsule

medial (tibial) collateral ligament (MCL)

connects the medial femoral epicondyle to the medial condyle of the tibia; directly adhered to the medial meniscus

lateral (fibular) collateral ligament (LCL)

narrow “cord-like” ban connecting the lateral femoral epicondyle and the head of the femur

anterior cruciate ligament (ACL)

attaches the lateral femoral condyle to the anterior intercondylar area of the tibia; prevents anterior translation of the tibia in relation to the femur

posterior cruciate ligament (PCL)

attaches the medial femoral condyle to the posterior intercondylar area of the tibia; prevents posterior translation of the tibia in relation to the femur

medial meniscus

fibrocartilage structure that is a shock-absorber for the knee; directly adhered to the MCL

lateral meniscus

fibrocartilage structure that is a shock-absorber for the knee; separated from the LCL

unhappy triad

injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus

ACL tear

ruptures due to hyperextension (too straight)

PCL tear

ruptures from landing on tibial tuberosity with a flexed knee