The fingers (from the Latin digitus) constitute the articulated ends located in the extension of the hands.

Position. The fingers are located in line with the hands, at the upper and lateral ends of the palm. There are five fingers (1):

• The 1st finger, called the thumb or pollux, is the only finger located on the most lateral part of the hand. Its position gives it greater mobility and efficiency in gripping.
• The 2nd finger, called index finger, is located between the thumb and middle finger.
• The 3rd finger, called middle or middle finger, is located between the index and ring fingers. It constitutes the reference axis for lateral movements.
• The 4th finger, called the ring finger, is located between the middle finger and the little finger.
• The 5th finger, called little finger of the hand or little finger, is located in the extension of the edge of the hand.

Finger skeleton. The skeleton of the finger is made up of phalanges. With the exception of the thumb which has only two phalanges, each finger is composed of three phalanges (1), articulated between them:

• The proximal phalanges articulate with the metacarpals, bones of the palm, and constitute the metacarpophalangeal joints.
• The middle phalanges articulate with the proximal and distal phalanges to form the interphalangeal joints.
• The distal phalanges correspond to the tips of the fingers.

Structure of the fingers. Around the skeleton, the fingers are made up (2) (3):

• collateral ligaments, stabilizing the metacarpophalangeal and interphalangeal joints;
• palmar plates, located on the palmar surfaces of the joints;
• flexor and extensor tendons of the fingers, originating from the various muscle compartments of the hand;
• skin ;
• fingernails located on the end of each finger.

Innervation and vascularization. The fingers are innervated by the digital nerves, branches originating from the median nerve, as well as by the ulnar nerve (2). They are supplied by the digital arteries and veins (3).

Information role. The fingers are highly sensitive, allowing a great deal of external information to be collected through touch and touch (3).

Execution role. The fingers allow gripping, which corresponds to all the functions allowing the grip (3).

Other roles of the fingers. The fingers also play an essential role in expression, nutrition, or even aesthetics (3).

Given their complex structure and their permanent use, the fingers can be affected by many pathologies whose causes are varied.

Bone pathologies.

• Fracture of the phalanges. The phalanges can be impacted and fractured. Extra-articular fractures must be distinguished from joint fractures involving the joint and requiring a thorough assessment of the lesions. Fractured bones of the fingers cause stiffness affecting the mobility of the fingers (4).
• Osteoporosis: This condition can affect the phalanges and is a loss of bone density that is usually found in people over the age of 60. It accentuates bone fragility and promotes bills (5).

Nervous pathologies. Different nervous pathologies can affect the fingers. For example, carpal tunnel syndrome refers to disorders associated with compression of the median nerve at the level of the carpal tunnel, more precisely at the level of the wrist. It manifests as tingling in the fingers and loss of muscle strength, especially in the palm (6).

Muscular and tendon pathologies. The fingers can be affected by musculoskeletal disorders, recognized as occupational diseases and arising during excessive, repetitive or brutal solicitation of a limb.

Joint pathologies. The fingers can be the seat of joint disorders, in particular arthritis grouping the pain associated with the joints, ligaments, tendons or bones. Osteoarthritis is the most common form of arthritis and is characterized by the wear and tear of the cartilage protecting the bones in the joints. The palm joints can also be affected by inflammation in the case of rheumatoid arthritis (7). These conditions can lead to deformity of the fingers.

Prevention of shock and pain in the palm of the hand. To limit fractures and musculoskeletal disorders, prevention by wearing protection or learning appropriate gestures is essential.

Symptomatic treatment. In order to reduce the discomfort, especially in the case of carpal tunnel syndrome, the subject may wear a splint at night.

Orthopedic treatment. Depending on the type of fracture, plaster or resin may be placed to immobilize the fingers.

Drug treatments. Depending on the pathology diagnosed, certain drugs may be prescribed to regulate or strengthen bone tissue, or allow the decompression of a nerve.

Surgical treatment. Depending on the pathology diagnosed, a surgical operation may be carried out, especially in certain cases of fractures.

Physical examination. First, a clinical examination is performed in order to observe and assess the sensory and motor signs perceived by the patient in the fingers.

Medical imaging exam. The clinical examination is often supplemented by an x-ray. In some cases, doctors will use an MRI, or CT scan, to assess and identify lesions. Scintigraphy or even bone densitometry can also be used to assess bone pathologies.

Electrophysiological exploration. The electromyogram makes it possible to study the electrical activity of the nerves and to identify potential lesions.

Symbolic of the fingers. Many symbols exist around the fingers. For example, the fourth finger owes its name “ring finger” to the use of this finger to wear the wedding ring in some religions.