Names of the HAND TENDONS

The hands are a very important part of our body that allows us to relate to others and to the environment in which we live. To do all this, the hands have a fundamental characteristic: great movement capacity. This is thanks to its structure, an intricate set of bones, muscles, joints, ligaments and, of course, tendons. Tendons are structures made of cartilage, similar to ropes, which are responsible for transmitting the movement of the muscles to the bones. In this lesson from a TEACHER we will review what are the main tendons of the hand, their position and their function. If you want to know more, we encourage you to keep reading!

Index

1. What are tendons?
2. What are the tendons of the hand?
3. Finger flexor tendons
4. Extensor tendons of the fingers
5. Thumb tendons

The tendonsThey are bands of connective tissueespecially cartilage and other cells. The type I cartilage that forms the tendons is made up of a set of fiber-shaped cells, which is specially designed to withstand the tensile forces and stretches that you constantly suffer tendons.

Surrounding the type I collagen fibers we find some cells, surrounded by a more or less gelatinous substance called matrix. The cells, which make up about 20% of the tendon, are: tenocytes, tenoblasts and fibroblasts. They are the cells responsible for the production of collagen fiber in different stages of specialization. Refering to matrix, which makes up the other 80% of the tendon, we mainly find water, elastin, proteoglycans and glycoproteins.

The hand is one of the most mobile regions of the human body. The tendons play a fundamental role in providing this great mobility since they are the responsible for communicating the movement created by the muscles of the hand and the proximal region of the arm to the bones of the hand.

The most mobile bones within the bones of the hand are undoubtedly the phalanges. The tendons in these bones not only have the function of motion transmission, but also the keep in a proper position, preventing them from slipping between them and causing dislocations.

In hand we have the following tendon groups:

• Finger flexor tendons
• Extensor tendons of the fingers
• Thumb tendons

Within the tendons of the hand we find the flexor tendons of the fingers:

• Deep flexor tendons. These tendons are responsible for bending the index, middle, ring, and small fingers at the fingertip joint. They all share the same muscle and, in each finger, the tendon divides near the base of the proximal phalanx and then inserts into the intermediate phalanx. These tendons are positioned closer to the bone than the rest of the flexors in the hand, which is why they are called deep tendons.
• Superficial flexor tendons. These tendons help the anterior tendons bring the fingertips closer to the palm of the hand. Unlike the previous ones, at the level of the fingers, each tendon divides into 2 separate branches; each of these branches attaches to the middle finger bone on either side of the deep flexor tendon of the fingers, which extends below the finger.

Image: Doctor Villanueva

The extensor tendons of the fingers are:

• Common extensor of the fingers: The common extensor tendon of the fingers is responsible for straightening the index, middle, ring and small fingers. All fingers share a common muscle, which is responsible for the movement of all of them, so it is very difficult for us to extend each of the fingers separately. The tendons travel up the forearm through a tough band of tissue at the top of the wrist, which keeps the tendons in place but allows them to slide up and down the arm. The four tendons continue along the back of the hand and end at the point of each of the fingers. In the finger, the ends of other tendons that start in the hand join with them to make the fingers move. Together, these combined tendons extend the fingers at the joints of the three fingers.
• Little finger extensor. This tendon is a tendon that does not appear in all human beings (in fact it appears in less than half of the population). Its function is to complement the action of the common extensor. This tendon is attached to the back of the little finger to straighten the three joints of the little finger.
• Extensor of the index finger. Like the extensor of the little finger, this tendon is responsible for helping the common extensor to straighten the index finger. It has its own muscular insertion in the forearm. In this case, the extensor of the index finger does appear in the vast majority of human beings, so this finger has a somewhat more independent mobility than the rest.

Image: Slideshare

We finish with the names of the tendons in the hand to focus on the thumb. The thumb, due to its position and short length, has independent tendons to those of the rest of the fingers. The tendons of the big toe are classified into two groups:

• Long abductor tendon of the thumb. This tendon runs on the radial side of the wrist, that is, on the side of the wrist where the thumb is. Its muscle attachment is in the forearm and then travels within a strong band across the wrist. It attaches to the metacarpal bone of the thumb and helps move the thumb away from the rest of the hand.
• Long flexor tendon of the thumb. This tendon is responsible for bending the thumb towards the inside of the hand and is unique to humans. It begins in the muscle in the forearm and then travels as a tendon in the wrist through the carpal tunnel. It is then covered with a tunnel or sheath, and inserted into the bone furthest from the thumb.
• Extensor pollicis longus tendon. This tendon is attached to the most distal phalanx of the thumb and its function is to straighten it.
• Short flexor tendon of the thumb. Together with the abductor pollicis longus it is responsible for separating the thumb from the palm of the hand.

If you want to read more articles similar to Tendons of the hand, we recommend that you enter our category of biology.

• Finnie, J (December 22, 2017) Structures of the Hand. Recovered from: https://teachmeanatomy.info/upper-limb/misc/structures-hand/
• American Society for Surgery of the Hand (s.f) Tendons. Recovered from: https://www.assh.org/handcare/safety/tendons
• Wikipedia (February 3, 2020) Tendon. Recovered from https://es.wikipedia.org/wiki/Tend%C3%B3n