The dorsal interossei are a group of intrinsic muscles located within the foot. Located in the deepest layer of plantar muscles, they are known to have a bipennate shape.
The attachment points of the dorsal interossei muscles include the lateral aspect of the metatarsals. The first muscle of this group attaches to the medial side of the proximal phalanx of the second digit, while the second to fourth interossei muscles attach to the lateral sides of the proximal phalanges of digits two to four.
When the dorsal interossei muscles are engaged, they function by abducting the lateral four digits and flexing at the metatarsophalangeal joints.
The dorsal interossei muscles are innervated by the lateral plantar nerve, and receive their blood supply from the dorsalis pedis, dorsal metatarsal, lateral plantar and plantar metatarsal arteries.
The clinical significance of the dorsal interossei cannot be overstated. These muscles are commonly subject to overuse injuries, with the most commonly affected area being the 2nd interosseous muscle which is linked to plantar fasciitis. This is because the action of the 2nd interossei muscle creates a tension force around the plantar fascia and the tendon of the flexor digitorum brevis, both of which attach to the base of the 2nd metatarsal.
Plantar fasciitis is an overuse injury of the plantar fascia which is the tissue that runs along the bottom of the foot. It results from the repetitive stress of the plantar fascia being pulled away from its attachment points on the heel bone or proximal phalanges. This repetitive stress causes inflammation and pain, especially during activities which involve walking, running, or jumping.
In addition to plantar fasciitis, the dorsalis interossei muscles are also at risk for developing tendonitis. Tendonitis is an inflammation of the tendon due to accumulated microtrauma resulting from overactivity. It can cause pain and discomfort in the area, as well as swelling and tenderness. In some cases, the tendon can become brittle or rupture if not treated in time.
These overuse injuries can be prevented by making sure to properly warm up and stretch before any physical activity. In cases where an injury is already present, it is important to rest the area and apply ice for 20 to 30 minutes several times a day to reduce any swelling. In addition, NSAIDs may be taken to reduce pain and inflammation. If pain persists, a visit to a doctor may be necessary.
The dorsal interossei muscles are an important group of intrinsic muscles located within the foot. They attach to the lateral aspect of the metatarsals and function to abduct the lateral four digits and flex at the metatarsophalangeal joints. These muscles are innervated by the lateral plantar nerve and receive their blood supply from the dorsalis pedis, dorsal metatarsal, lateral plantar and plantar metatarsal arteries. Although they are essential to the movement and stability of the foot, they are also susceptible to overuse injuries such as plantar fasciitis and tendonitis. Taking the necessary precautions, such as properly warming up and stretching, can help to prevent these injuries and maintain the health of the foot.
