Lower limb
Spring ligament complex (Plantar calcaneonavicular) & Bifurcate ligament
Ligamentum calcaneonaviculare plantare (Spring ligament) & Ligamentum bifurcatum
- Origin
- Sustentaculum tali and anterior process of calcaneus
- Insertion
- Plantar surface of navicular (spring ligament) and cuboid (bifurcate ligament)
- Function
- Forms fibrocartilaginous sling cradling the talar head; primary static supporter of the medial longitudinal arch; bifurcate ligament stabilizes Chopart joint
- Innervation
- Medial plantar nerve (L4–L5)
- Movement & chain
- Elastic recoil and dynamic arch suspension during stance-phase push-off
- Palpation
- Palpable medially between sustentaculum tali and navicular tuberosity
- Clinical
- Spring ligament attenuation/rupture causing severe flatfoot collapse (Adult-Acquired Flatfoot Deformity - AAFD); bifurcate ligament avulsion fracture in severe inversion.
- Segmental innervation
- L4–S1
- In clinical practice
- Single-leg heel rise test, medial longitudinal arch custom foot orthoses, and tibialis posterior tendon loading
- Region in the model
- Lower limb