It acts principally on the proximal phalanges, the middle and terminal phalanges being extended mainly by the interossei and lumbricales.
Additionally, the interossei act as plantar flexors at the metatarsophalangeal joints.
The considerably smaller flexor digiti minimi brevis on the lateral side can be mistaken for one of the interossei.
This occurs because the ulnar nerve also innervates the palmar and dorsal interossei of the hand.
The lateral part of the first dorsal interossei muscle originates from the medial side of the bone.
Flexion is primarily performed by intrinsic foot muscles; the second toe (the) is unique as it has two dorsal interossei but no plantar interossei muscles.
The third dorsal interossei from the medial side of the bone and the fourth dorsal interossei from the lateral side.
The second dorsal interossei from the medial side of the bone and the third dorsal interossei from the lateral side.
