The human hand comprises structures such as bones, joints, ligaments, tendons, muscles, nerves, and blood vessels. These structures work collectively to facilitate hand movements. Proper alignment and coordination between these structures is very important for the normal hand function. The bones provide the structure for the fingers and the wrist. Tendons are tough bands of tissues that attach the muscles to the bones. The bands of tissues belonging to the extrinsic muscle groups facilitate physical movements such as bending and straightening the fingers. The range of motion of the hand can get restricted, if these bands of tissues get damaged.
Tendons of the Hand
The tendons of the wrist and hands are basically categorized into extensor and flexor tendons. These include:
- Flexor Pollicis Brevis flexes the thumb at metacarpophalangeal joint.
- Flexor Pollicis Longus flexes the thumb.
- Flexor Digitorum Profundus flexes the distal phalanx.
- Flexor Digitorum Superficialis flexes fingers at proximal interphalangeal joint.
- Abductor Pollicis Longus abducts, rotates, and extends the thumb.
- Abductor Pollicis Brevis abducts the thumb, acts with muscles of the thenar eminence to oppose the thumb.
- Extensor Pollicis Longus extends the thumb.
- Extensor Pollicis Brevis extends the thumb.
- Extensor Digitorum Communis extends the fingers and the wrist.
- Opponens Digiti Minimi rotates 5th metacarpal bone forward.
- Opponens Pollici rotates the thumb in opposition with fingers.
The extensor tendons are the tough cords of tissue that run from the muscles in the forearm, across the back of the hand to the thumb and fingers of each hand. These allow the finger joints to straighten. These bands of tissues are extra-synovial, except at the wrist. When they travel towards the fingers, they form the extensor hood. Extensor minimi digiti is the small tendon that allows you to straighten the little finger. Extensor digitorum is a large tendon that helps with the extension of hands as well as fingers. Extensor pollicis brevis and extensor pollicis longus are both responsible for the extension of thumb.
The flexor tendons also begin from the muscles in the forearm and run from the palm to the fingers and thumbs. These allow you to perform movements such as making a fist, grasping objects, and bending your fingers and thumbs. Every finger contains two flexor tendons, whereas a single tendon is present in each thumb. Flexor carpi radialis and flexor carpi ulnaris are responsible for the flexion of the wrist whereas flexor digitorum superficialis and flexor digitorum profundus insert into the middle phalanx and the distal phalanx respectively.
If the tendons in the hand and fingers get damaged due to injuries or any medical condition, we wouldn't be able to perform several tasks. At times, these may get damaged due to repetitive strain due to strenuous physical activities. It could lead to a medical condition called hand tendonitis. This condition not only causes pain, swelling, and stiffness in the hands, it could restrict the hand movements considerably. Since these are situated very close to the surface of the hand, these can get damaged easily. The flexor tendons generally get damaged due to cuts. You might have seen that when you make a fist, there are creases at which the skin folds. Since these are located very close to the skin, even a small cut could cause damage.
Flexor tenosynovitis is a medical condition that is characterized by inflammation of the sheath that lubricates and protects the flexor tendons. Individuals affected by flexor tenosynovitis often experience symptoms such as pain, swelling, and tenderness. If left untreated, one might find it hard to move the affected finger or thumb. The extensor tendons could get damaged due to overuse injuries, cuts, puncture wounds, arthritis, or tendonitis.
Medical assistance must be sought to treat these conditions. The extent of damage can be determined through an X-ray examination of the hand. The application of ice packs and the use of anti-inflammatory drugs or pain killers might be recommended, but in some cases surgery might be required. Until the patient recovers completely, the affected hand is placed in a cast. The patient is often advised to go for physical therapy in order to strengthen the muscles and tendons.
Though tendons that are located in the hands are tough, these can get damaged due to overuse or stress injuries. They might take a lot of time to heal and until that time, the range of motion of your hand might be greatly restricted. It is therefore, very important that you avoid highly strenuous activities.