Corpus: Opponens digiti minimi muscle of foot
1. Definition
The opponens digiti minimi muscle of the foot is an inconstant muscle of the foot, specifically located in the area of the little toe. It shares its name with the opponens digiti minimi muscle of the hand. Some authors consider this muscle to be a derivative of the flexor digiti minimi brevis muscle.
2. Course
2.1. Origin
The opponens digiti minimi muscle of the foot shares its origin with the flexor digiti minimi brevis muscle, including:
- The plantar side of the base of the fifth metatarsal bone
- The long plantar ligament
- The tendon sheath of the peroneus longus muscle
2.2. Attachment
The muscle attaches to the lateral edge of the distal half of the fifth metatarsal bone
3. Innervation
The opponens digiti minimi muscle is innervated by the lateral plantar nerve, a branch of the tibial nerve.
4. Function
The function of the opponens digiti minimi muscle is variably described in the literature. Due to its fiber orientation, the muscle can cause a slight rotation or opposition of the fifth metatarsal bone, aiding in the tensile support of the arch of the foot. While abduction and flexion of the little toe are also mentioned as potential functions, these are generally ruled out due to the muscle's specific insertion point.