- "the diamond-shaped space at the base of the pelvic cavity, also called the pelvic outlet."
- It is bordered by:
- 1) pubic symphysis.
- 2) ischiopubic rami.
- 3) ischial tuberosities.
- 4) sacrotuberous ligaments.
- 5) coccyx.
- It is divided into two triangles: the urogenital triangle - the anterior triangle and the anal triangle - the posterior triangle
- Levator ani & coccygeus
- deep to the muscles in the urogenital triangle (more superior).
- These muscles cover the pelvic outlet with hiati for urinary and genital organs and the anus. They are bowed downward forming a funnel-like structure
- 1) pubococcygeus
- runs from the pubes and tendinous arch of obturator internus muscles back to the coccyx
- 2) iliococcygeus
- runs from the tendinous arch of obturator internus muscles and the ilia to the coccyx.
- 3) puborectalis
- runs from the pubes back towards the anus
runs from the pubes and tendinous arch of obturator internus muscles back to the coccyx
runs from the tendinous arch of obturator internus muscles and the ilia to the coccyx.
runs from the pubes back towards the anus
runs from ischial spine to coccyx
fills anterior triangle; inferior to pelvic diaphragm
the posterior triangle
forms the upper lateral wall of the pelvic bowl. The tendinous arch is a thickening of the fascia on medial surface; acts as lateral attachment site for the pubococcygeus and the iliococcygeus.
run from the ASIS to the pubis and are formed from a fold in the fascia of the abdominal wall
run from TP�s of L5 and the TP�s of L4 to the crest of the ilium
numerous ligaments both on the anterior and posterior surfaces of the sacrum that help stabilize the SI joints.
run from ischial spine to sacrum
run from the ischial tuberosity to the sacrum
Sacroiliac joints (2):
joins the two coxal bones (appendicular) to the sacrum (axial).
slightly moveable joint which has a fibrocartilaginous disc between the two coxal bones that allows them to torque on each other during locomotion.
formed from 2-4 fused segments
Sacrum: formed from five fused segments (usually in the 20�s)
- a) sacral foramina: openings through which nerve roots pass
- b) base: the most superior aspect; acts as the base for the overlying vertebral column.
- c) apex: the most inferior aspect; articulates with the coccyx
- d) inferior lateral angle: just lateral to the apex
- e) auricular surface: �ear-shaped� surface that articulates with the coxal bones
"three fused bones; ilium, ischium and pubis"
Two areas of heightened awareness near the knee
- Popliteal regioin
- Common peroneal nerve
area behind the knee has the popliteal artery and vein as well as the tibial nerve just underneath the surface of the skin
common peroneal nerve
an offshoot of the sciatic nerve that is near surface just posterior to the head of the fibula.
Three important pairings of lower leg muscles:
- 1) The �ice tongs� peroneus brevis and tibialis anterior
- 2) The �stirrup� peroneus longus and tibialis anterior
- 3) The �sling� tibialis posterior and peroneus longus.
The �ice tongs�
peroneus brevis and tibialis anterior
peroneus longus and tibialis anterior
tibialis posterior and peroneus longus.
the deep or investing fascia of the foot; is a continuation of the crural
is the a thickening of the plantar fascia
intrinsic plantar muscles:
4 layers of muscle that start and end in the foot.
flexor hallucis longus
- P: posterior shaft of fibula.
- D: distal phalanx of great toe.
- A: flexion of great toe and assists in plantarflexion.
- tendon runs underneath the sustentaculum tali of the calcaneus
flexor digitorum longus
- P: posterior shaft of tibia.
- D: distal phalanges of 4 toes on the plantar surface.
- A: flexion of toes and assists in plantarflexion
- "P:posterior tibia, fibula and interosseous membrane."
- D: numerous bones on plantar surface of foot including the middle 3 metatarsals.
- A: inversion and plantarflexion
Muscles of the posterior compartment of the leg - deep layers:
- Tibialis posterior
- Flexor Digitorum longus
- Flexor Hallucis Longus
- P: lateral epicondyle of femur.
- D: medial condyle of the tibia.
- A: flexion of knee and medially rotates the tibia
- P: lateral epicondyle of femur.
- D: calcaneus via Achilles tendon.
- A: assists in knee flexion and plantarflexion.
- P: posterior proximal tibia and head and upper shaft of fibula.
- D: calcaneus via the Achilles tendon (which it shares with the gastroc).
- A: plantarflexion
- P: two heads; posterior surfaces of medial and lateral epicondyles of femur.
- D: calcaneus via the Achilles tendon.
- A: plantarflexion and will assist in flexion of knee
Muscles of the posterior compartment of the leg- superficial layer:
- P: lower 2/3 lateral shaft of fibula covered by the longus.
- D: lateral tubercle of 5th metatarsal.
- A: eversion and plantarflexion
- P: upper 2/3 lateral shaft of fibula and across plantar surface of foot.
- D: plantar base of the 1st metatarsal and 1st cuneiform.
- A: eversion and plantarflexion
Muscles of the lateral compartment of the leg
- Peroneus longus
- Peroneus brevis
- P: medial to anterior ridge of fibula.
- D: base of 5th metatarsal.
- A: eversion and assists in dorsiflexion; only in about b20-30 % of population.
extensor hallucis longus
- P: anterior shaft of fibula and interosseous membrane.
- D: superior base of distal phalanx of great toe
- A: extension of great toe and assists in dorsiflexion
extensor digitorum longus
- P: lateral condyle of tibia and proximal 2/3 anterior shaft of fibula.
- D: middle and distal phalanges of the four toes.
- A: extension of toes and assists in dorsiflexion of ankle
- P: lateral shaft of tibia and interosseous membrane.
- D: base of 1st metatarsal and 1st cuneiform.
- A: dorsiflexion of ankle and inversion of foot
Muscles of the anterior compartment of the leg:
- Tibialis anterior
- Extensor Digitorum Longus
- Extensor Hallucis Longus
- Peroneus Tertius
synovial tubes through which tendons pass; allow for free movement of tendons especially beneath the retinacula
thickenings of the crural fascia that �retain� the tendons that cross the ankle joint
continuations of the crural fascia deep into the leg that attach to the tibia and fibula; separate the major muscle groups from each other
the deep or investing fascia of the lower leg ; a continuation of the fascia lata.
short plantar (plantar calcaneocuboid) ligament
lies deep to the long plantar ligament and runs from the plantar surface of the calcaneus to the proximal plantar surface of the cuboid.
long plantar ligament
runs from plantar surface of tuberosity of the calcaneus to the bases of metatarsals II-V.
plantar calcaneonavicular ligament
the �spring� ligament which runs from the sustentaculum tali to the navicular and helps support the head of the talus( even though it is not attached to the talus) and limits flattening of the medial longitudinal arch
Ligaments of the foot
- plantar calcaneonavicular ligament
- long plantar ligament
- short plantar (plantar calcaneocuboid) ligament
talocalcaneal (or subtalar) joint
articulation between the inferior articular surface of the talus and the superior surface of the calcaneus; allows for inversion and eversion of the foot.
the articulation of the superior surface of the talus and the overlying tibia allowing for plantar/dorsiflexion
Ankle and foot joints:
- tibiotalar joint:
- talocalcaneal (or subtalar) joint
- a) proximal: a synovial joint allowing only a slight movement of the two bones
- b) distal: a fibrous joint with little movement
- c) interosseous membrane: tough sheet of connective tissue running between the two bones
anterior and posterior cruciate ligaments
two criss-crossing ligaments found within the knee joint ACL resists anterior displacement of tibia on the femur PCL resists posterior displacement of tibia on femur. In both flexion and extension they remain taut to hold tibia against femur.
medial and lateral menisci (sing. - meniscus)
two C-shaped discs of fibrocartilage found between the femur and the tibia that are attached at the intercondylar tubercles and loosely to the joint capsule on the perimeter. They increase the surface area between the two bones and act to absorb some of the force exerted between the two bones
medial (tibial) and lateral (fibular) collateral ligaments
MCL attaches to the medial epicondyle of femur and the medial condyle of the tibia; is part of the joint capsule and attaches to the medial meniscus. LCL attaches to the lateral epicondyle of the femur and the head of the fibula; it is not attached to the joint capsule. they both tighten in extension thereby resisting hyperextension
the knee cap; articulates only with the femoral condyles.
consists of the two convex femoral condyles articulating with the two slightly concave condyles found on the superior aspect of the tibial platform.
- a) medial longitudinal
- "consists of the talus, navicular, three cuneiforms and first three metatarsals/phalanges"
- b) lateral longitudinal
- "consists of the calcaneus, cuboid and 4th and 5th metatarsal/phalanges"
- c) transverse
- consists of the three cuneiforms and the cuboid
- a) hallux: proximal phalanx and distal phalanx
- "b) digits 2-5: proximal, middle and distal phalanges"
- a) I - V
- b) base
- c) head
- d) sesamoid bones
- a) talus:
- b) calcaneus:
- 1) sustentaculum tali
- a small projection off the posterior medial surface of the calcaneus that works to support the overlying talus
- c) cuboid:
- d) navicular
- "e) cuneiforms (1st, 2nd, and 3rd) "
- a) head
- b) shaft
- c) lateral malleolus
- a) shaft
- b) tibial platform:
- 1) medial condyle
- 2) lateral condyle
- 3) intercondylar ridge
- c) tibial tuberosity
- d) medial malleolus