Layer 2:
Quadratus plantae:
- Originates on the medial and lateral sides of the calcaneus
- Inserts on the tendons of flexor digitorum longus
- Aids in toe flexion.
Lumbrical:
- Originate on the tendons of flexor digitorum longus
- Insert on the extensor expansions associated with the phalanges of toes 2—5.
- The lumbricals have two actions on digits 2—5:
They flex the proximal phalanges, and,
They extend the middle and distal phalanges.