Superficial transverse metacarpal ligament
Ligamentum metacarpeum transversum superficiale
The superficial transverse metacarpal ligament is a band of crosswise fibres in the distal palm, part of the palmar aponeurosis near the finger bases.
At a glance
- English
- Superficial transverse metacarpal ligament
- Latin (TA2)
- Ligamentum metacarpeum transversum superficiale
- System
- Muscle
- Region
- Upper limb
- Side
- Paired, left and right
About the superficial transverse metacarpal ligament
The palmar aponeurosis is the tough triangular sheet of fascia under the skin of the palm. Most of its fibres run lengthwise, in four pretendinous bands that pass towards the fingers. Near the bases of the fingers a set of fibres runs across the palm instead, and this crosswise band is the superficial transverse metacarpal ligament. It lies just under the skin, in front of the flexor tendons and the digital nerves and vessels, at about the level of the metacarpal heads.
Its fibres stretch across from the radial to the ulnar side of the distal palm, lying deep to the pretendinous bands and binding them together. Vertical septa pass from it down to the deep fascia and the deep transverse metacarpal ligament, dividing the distal palm into tunnels for the flexor tendons and for the lumbricals with the nerves and vessels. Distally similar crosswise fibres in the finger webs form the natatory ligament, which runs parallel and slightly further towards the fingertips.
The band holds the longitudinal bands of the aponeurosis in place and keeps the distal palm firm when gripping. It also limits how far the fingers can spread apart and helps protect the structures beneath it from pressure.
Naming in this region is not uniform. Some writers use the term for the transverse fibres of the palmar aponeurosis, also called the ligament of Skoog, while others apply it to the natatory ligament in the webs. In Dupuytren disease, the natatory fibres can thicken into cords that narrow the web spaces, while the deeper transverse fibres are usually spared, which helps surgeons find their way.
Attachments, action and supply
- Origin
- Radial side of the distal palmar aponeurosis, at the level of the metacarpal heads.
- Insertion
- Ulnar side of the distal palmar aponeurosis, with septa passing down to the deep fascia.
- Action
- Binds the pretendinous bands together, firms the distal palm in grip and limits spreading of the fingers.
Anthromica
See the superficial transverse metacarpal ligament where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
