Lower Extremity Ligaments

Sacrotuberous Ligament

• extends from sacrum to ischial tuberosity

• helps convert greater sciatic notch into greater sciatic foramen

• forms greater sciatic foramen and less foramen with sacrospinous ligament

• limits upward movement of the inferior end of the sacrum (anterior tilt)

Sacrospinous Ligament

• from sacrum to ischial spine

• helps form lesser sciatic foramen

• limits upward movement of the inferior end of sacrum

Anterior sacroiliac ligament

• thin band that extends from anterior surface of the sacrum to the medial aspect of iliac fossa to ilium

• strengthens joint anteriorly

Interosseous sacroiliac ligament

• very strong

• primary structure for force transmission and in WB

• keeps the SI joint as close as they can be

Posterior sacroiliac ligament

• thick band from posterior surface of articulating bones

• continuous with interosseous sacroiliac ligaments

• strengthens joint posteriorly

Superior pubic ligament

• b/t the two pubic crests

• strengthens superiorly

Arcuate (inferior) pubic ligament

• b/t inferior pubic rami

• strengthens inferiorly

Iliofemoral (Y) ligament

• strongest, limits hyperextension

• ASIS to intertrochanteric line

• provides static restraint to gravitational pull during standing

Pubofemoral ligament

• limits abduction and extension

• pubis to fibrous capsule

• reinforces inferiorly and anteriorly

Ischiofemoral Ligament

• posterior, limits internal rotation & extension

• ischial part of acetabulum to neck of femur

• reinforces capsule posteriorly

• prevents hyperextension- pulls femoral head into the acetabulum

Ligament of femoral head (ligamentum teres)

• from acetabular notch to fovea on femoral head

• small contribution to stability

• houses a small artery in children

Patellar ligament

• strong thick fibrous band

• extends from patella to tibial tuberosity

• restricts excessive knee flexion

Fibular (collateral) ligament

• restricts varus stress and lateral rotation of tibia

• strong, cord-like

• extends from lateral epicondyle of femur to lateral surface of fibular head

• doesn’t attach to lateral meniscus

Tibial (medial) collateral

• restricts valgus stress and lateral rotation of tibia

• medial epicondyle of femur to medial condyle of tibia

• deep fibers attach to medial meniscus

• more injuries here bc weaker than LCL

Oblique popliteal ligament

• supports posterolateral knee

• blends with fibrous capsule

• restricts hyperextension

Arcuate popliteal ligament

• supports posterolateral knee

• passes over the popliteus tendon

Anterior Cruciate Ligament (ACL)

• most taut when knee in full extension

• prevents posterior glide into hyperextension when femur is moving on fixed tibia (also anterior glide if tibia moving)

• weaker than PCL

• poor blood supply

Posterior Cruciate Ligament (PCL)

• fibers taut in flexion

• prevents anterior glide of femur on fixed tibia (prevents posterior glide if tibia moving)

• stronger than ACL

• injured w/ hyperflexion

Medial Menisci

• C-shaped

• broader posteriorly

• outer regions blend with MCL

• more prone to injury than lateral menisci bc less mobile on tibial plateau

Lateral Menisci

• separated from LCL to popliteus tendon

• less prone to injury because more mobility

Lateral Collateral Ligament of ankle

Restricts foot inversion

1. Anterior talofibular- most commonly sprained

2. calcaneofibular

3. posterior talofibular

Medial Collateral Ligament/Deltoid Ligament

Restricts foot eversion

1. anterior tibiotalar

2. tibionavicular

3. tibiocalcaneal

4. posterior tibiotalar

Spring Ligament (plantar calcaneonavicular)

• extends from sustentaculum tali of calcaneus to the navicular

• supports the head of the talus → prevents displacement of the talas b/t the navicular and calcaneus

Anterior Longitudinal Ligament

• occiput to sacrum

• supports anteriorly, restricts hyperextension (only one to do this!!)

• wider than posterior ligament

Posterior Longitudinal Ligament

• occiput to sacrum

• prevents hyperflexion of vertebral column and posterior protrusion of intervertebral disc

• more narrow than anterior lig

Ligamentum flavum

• lamina to lamina, between each successive vertebrae

• prevents separation of lamina, resists abrupt flexion

Interspinous ligaments

• between spinous processes

• resists flexion

Supraspinous ligaments

• connect adjoining spinous processes

• resist flexion

Intertransverse ligaments

• connect adjacent transverse processes

• prevent lateral flexion

Nuchal ligament

• occiput to cervical vertebrae

• resists flexion

Iliolumbar ligament

• LV 4-5

• anchors lower vertebral column to iliac

• stability to lumbosacral joint

Cruciate ligament of atlas

• looks like a cross

• transverse ligament runs horizontal

• vertical longitudinal bands (superior & inferior)

• anchors dens to atlas

Alar Ligament

• sides of dens to foramen magnus

• prevents excessive rotation