Index finger anatomy

introduction

The index finger (lat. index) is the second finger of our hand. On each hand there is an index finger between the thumb and middle finger. Its basic structure consists of three bones, the so-called phalanges.

anatomy

In the order from fingertip to finger base there is an upper, a middle and a lower phalanx. The lower phalanx (Phalanx proximal) is in turn connected with tendons to the second metacarpal, which gives the index finger both stability and freedom of movement. The bones are attached from there and are essential for movement Tendons, Adipose tissue and skin.
The skin of the index finger becomes complete on the palm side and on the back side of the hand except for the fingertip portion of that Median nerves (middle arm nerves) supplied with sensitive fibers that are important for feeling perception. The fingertip on the back of the hand is pushed through the Radial nerve (Spoke nerve) sensitively supplied.

Tendons and ligaments

Numerous tendons end on the index finger that are responsible for the motor function, but also his stability are very important. Much of the tendons come from it Muscleswhich originated in the area of ​​the Elbow or Forearm own, pull over it and finally place it on the bone of the index finger. When these muscles contract, this leads to certain exercise Finger movementssuch as flexion, extension, splaying, and pulling in. The tendons that are responsible for stretching the fingers attach to the knuckles on the side of the back of the hand. In total there are two muscles responsible for this movement, the Index finger extensor (Extensor indicis muscle) and the general finger extensor (Extensor digitorum communis muscle).

The tendons of the muscles responsible for flexion attach to the knuckles on the side of the palm. Here, too, there are two muscles that are largely responsible for movement. On the one hand, this is the superficial (Flexor digitorum superficialis muscle), on the other hand the deep finger flexor (Flexor digitorum profundus muscle). The Flexor tendons are held by a ring-shaped band (Annular ligament) reinforced. The ring band is part of the Tendon sheath, in which the tendons are embedded and which ensures their gliding ability. The annular ligament prevents the tendons from sticking out from the bone like a bowstring when flexing, since otherwise the motor skills and function of the index finger would be immensely restricted.

Paresthesia (numbness)

One numb fingers there can be many causes. Usually it is the result of Blood circulation disorders or in the Supply of nerves, especially if the corresponding nerve is pinched. This can also be accompanied by tingling sensations, a cold index finger and stabbing pain. Think of this as Paresthesia or Paresthesia together.

Each of the manifestations can be perceived as very stressful for those affected, which is only one of the reasons why a medical clarification of the complaints, especially if they occur more frequently, makes sense. The Numbness I'm sure all of us know as fingers asleep. If the feeling is temporary and disappears when you move your index finger, there is usually no serious illness behind it.

This is a very common disease that leads to pain and discomfort, including in the area of ​​the index finger Carpal tunnel syndrome. There is a narrowing of the Median nerves. The problem, especially the pain, typically occurs at night. Motor disorders can accompany an advanced carpal tunnel syndrome. This is expressed, among other things, in a Reduced hand strength. Closing a fist is only possible to a limited extent. Can be therapeutically Cortisone injected around the nerve. However, many sufferers only get rid of their suffering through a small operation. During this procedure, a ligament in the area of ​​the bend of the hand, under which the nerve runs and which is also responsible for its narrowing, is split.

In addition to reduced nerve stimulus transmission due to constriction and pressure on the nerves, a impaired blood flow Cause numbness in the area of ​​the index finger. You should be particularly careful if the symptoms only occur on one side and are accompanied by other sensory disorders on the same side of the body.

If, in addition to numb fingers, there are also abnormal sensations in the area of ​​the face on the same side, arm or leg, as well as reduced strength, which are expressed as a hanging corner of the mouth, weak arm or weak leg, this can be an indication of a stroke. Acting quickly is vital. In case of doubt, the emergency doctor should be called if there is the slightest suspicion of a stroke.

Not only a disorder of the nerves in the hand area can lead to numbness in the fingers and especially in the area of ​​the index finger. If there is a constriction and compression of the nerves in the area of ​​the cervical spine, for example due to a herniated disc in the cervical spine, this can also lead to the same problem. Discomforts that appear suddenly and do not go away or those that persist over a longer period of time and may get worse should be taken seriously. Accompanying pain or paralysis should also be clarified by a doctor. The therapy depends on the triggering cause, insofar as this can be determined.

Read more on our website Numbness in the finger

Tape dressings

Some sports, how Handball, volleyball or climbing, stresses the fingers, including the index finger, very much. They harbor the risk of injury or overstretching of the capsule and ligament structures. This is very painful and the recovery can take a few weeks, whereby a complete restoration of the healthy initial state is usually no longer achieved.

To prevent injuries, the fingers, especially the index finger, can be taped. But fingers that have already been injured can also use a Tape association be supported and stabilized. Care should always be taken to ensure that the index finger does not hurt, become numb or fat in the stabilizing position. The tape bandages can differ in nuances for each sport.

However, the basic ideas behind it are the same. A wide variety of tape bandages are suitable for acutely injured index fingers. Here it is advisable to consult a physiotherapist or a specialist doctor before trying, in order not to provoke more problems. The following text describes how to fix a stabilizing tape dressing to prevent injuries.

Ideally should be a 1.5-2 cm wide tape can be used. In the first step, a piece of tape is attached around the index finger above and below the middle joint. The pieces of tape sit almost like two rings around the index finger, with the middle joint left out and still movable. These basic features are known as anchor. Then the two taper rings are connected to one another lengthways and tightly in the area of ​​the middle joint using another piece of tape. The length of the tape bandage attached should not exceed the length of the ring-shaped bandages attached first. If the desired stability is not achieved, another piece can be glued in the same position. It also applies to the following steps: the more tapes are attached, the more stable the bandage. However, it should always be ensured that the taped index finger does not hurt, become numb or swell. If any of these symptoms occur, the bandage must be removed immediately.

The next step is what are called diagonal trains appropriate. The tape is attached to the middle of the finger on the lower of the two ring-shaped anchors, starting from the fingertip. Then it is guided upwards and outwards over the lengthways attached tape, whereby the upper joint pole of the middle finger joint is again left out. Once there, the bandage is pulled down over the top of the upper index finger and attached to the lower anchor on the lower finger. You apply this bandage in the shape of an eight. In the last step, two ring-shaped tape bandages are attached again, as in step 1, above and below the middle of the index finger joint.

Index finger twitching

Involuntary muscle twitches can appear all over the body, but more often in the arms and legs, as well as on the index finger and face. They usually set in suddenly and can be of various intensity and duration. Some twitches occur rhythmically in their duration, others at irregular intervals. As a rule, spontaneously occurring, occasional twitches that quickly disappear are not pathological.
However, if the finger twitches occur more often and also in other parts of the body, a visit to a doctor should be considered, as a disease of the nerves and muscles should be excluded, even if this is very rare.

Those affected usually feel no pain during the twitching. However, if they occur more frequently or for a longer period of time, there is a risk of one Muscle spasmwhich can be perceived as very painful. Some people suffer from twitching of the fingers, including in the area of ​​the index finger Stressful situation, especially if they are very nervous. Depending on the severity, this can make the situation even worse, as targeted movements are sometimes hardly possible.

As already mentioned, the twitches can also be caused by neurological diseases, which should not be ignored if they occur frequently. Muscle twitching occurs, including on the index finger, as part of a epilepsy, amyotrophic lateral sclerosis (ALS) or Multiple sclerosis on. People under one Tourette syndrome suffer from muscle twitching all over their body. The diabetes Diabetes mellitus leads to the destruction of the smallest vessels that supply the nerves. The undersupplied nerves perish. This can also manifest itself in muscle twitching accompanied by abnormal sensations such as numbness and tingling in the area of ​​the index finger.

Under a tremor one understands rhythmic, repetitive muscle twitches. It is often perceived as a tremor. Parkinson's patients suffer from it permanently. In some patients, the tremor occurs as an independent clinical picture without any other underlying disease. This form, which is usually hereditary, is called essential tremor. More serious illnesses can be examined by the doctor using various measuring methods and, at best, excluded.
The nerves can use the Electroneurographywho have favourited muscles using the Electromyography to be examined. With both methods, nerves or muscles are electrically stimulated via a small electrode and their "response" is recorded. The corresponding image can then be evaluated. If there is a suspicion that the twitches are caused by a disorder in the brain, as would be the case with epilepsy, a Electroencephalography (EEG) provide information. With the EEG, brain activity is recorded using electrodes attached to the skin. The therapy depends on the triggering cause.

Index finger pain

The most common reasons for index finger pain are inflammatory processes and wear and tear on cartilage and bone, that is Degenerations (please refer: Finger inflammation).
A common inflammation in the finger area is Tendinitis. The tendon sheaths encase the tendons. The fluid it contains makes the tendons more slippery and thereby reduces the friction that acts. Those affected complain of severe, pulling to stabbing pain on the affected index finger. The finger is also often red, swollen and tender.

However, this is more common wrist affected (see: Wrist pain).
The causes are also diverse here. In addition to a Inflammation from germs, especially bacteria, sustained constant movements, accompanied by increased friction between a tendon area and the bone, can lead to painful tendinitis. Such movements are performed during long computer work and in various sports such as floor exercise, climbing and tennis. Musicians who play the guitar, violin or piano also often suffer from the symptoms mentioned. The best therapy is that The finger is immobilized in a plaster castso that the already irritated tendon is spared excessive movement. The Cool with ice often already provides relief. It is advisable anti-inflammatory pain relievers, how aspirin, Ibuprofen or Diclofenac to take. You should seek advice from a doctor about the duration and amount of medication, especially since the medications mentioned often cause gastrointestinal complaints and, if used for a long time, a stomach protector should also be taken.

Not only inflammation of the tendon sheath leads to pain in the index finger, but also Inflammation of the joints. There are three of them on the index finger.
A Joint inflammation is technically called arthritis designated. On the finger joints, it is very often associated with a rheumatic genesis on. The typical signs of the rheumatoid arthritis are morning stiffness. This means that after waking up the fingers are only fully able to move after more than 30 minutes, joint swellings occur in more than 2 finger joints and that the joints on both sides of the body are symmetrically affected by the complaints.
Those affected suffer from pain, which occurs mainly when moving. Due to the constant inflammation, over the years there is a risk that the knuckles around the affected joints will be attacked, destroyed and deformed. A cortisone, a so-called glucocorticoid, is often used to inhibit the inflammation, as prescribed by the doctor. The drugs mentioned for tendinitis can help relieve the pain. There should also be an additional gastro-protective drug be thought.

Of the physical therapy also plays a major role in maintaining joint mobility for as long as possible. Numerous, newer drugs are able to block inflammatory cells and neurotransmitters and thus attack the cause of the problem. However, a doctor should always be consulted for more precise therapy planning.

The last big cause of aching forefingers is that Joint wear, better also than arthrosis known. The middle and end joints of the fingers are particularly affected, including the index finger, as well as that Saddle thumb joint.
The basis for joint wear is the previous one Damage to the cartilage. This becomes cracked and rough and can no longer fulfill its functions as a slide bearing and protective layer in the joint area. The bones rub against each other and respond with increased bone formation, which over time becomes painful Stiffening of the affected (finger) joint can lead. The increased friction irritates the synovial membrane, which is largely responsible for the production of the joint water. Result are Swelling of the affected finger joints. The pain is treated with the drugs mentioned above. Overuse of the affected joints should be avoided. As part of a Occupational therapy Joint-friendly work can be learned.