What is the adductor reflex?The adductor reflex is a self-reflex of the muscles known as adductors and muscle groups in the thighs and arms.
The adductor reflex is triggered by a blow on the medial bony prominence of the long bones of legs or arms. It comes to tightening the arms or legs to the body. Thus, 'adduction' is the Latin term for 'getting involved'. In medicine, it means bringing a part of the body to the body. This attraction takes place with the so-called adductors. These are the muscles and muscle groups that align the longitudinal axis of the limbs with the body's longitudinal axis. In this way, the adductors ensure, among other things, that a splayed leg or a splayed arm is brought to the body. The same applies to splayed thumb and toe. Illnesses of the adductors are usually caused by sports injuries.
Strictly speaking, the adductor reflex is mainly related to the reflex response of the thigh adductors. Responsible for this is the Nervus obturatorius, which has its origin in the 2nd to 4th lumbar segment of the spinal cord as a nerve of the loin plexus (lumbar plexus).
The adductor's reflex is a self-reflex and thus takes place where the stimulus has occurred. By repeating the reflex response does not weaken in contrast to the extraneous reflex.
Function & Task
In the adductor reflex, the reflexes of the adductors in the thigh are tested. Thus, a statement about the function of the obturator nerve is possible.
The adductor reflex belongs to the group of self-reflexes. Here, signals from muscle strains are transmitted via a single synapse to the alpha-motoneuron in the spinal cord and transmitted back to the corresponding muscle via the motor nerves. It comes to the reaction of the muscle in the form of a reflex. The reflex leads to a visible twitch of the muscle, which then performs its typical movements. In adductors, the reflexive approach of the irritated limbs to the body occurs.
The reflex response in an adductor reflex is physiological. Only an absence or amplification of this reflex would indicate a perturbation of the stimulus transmission.
The adductors are in constant interplay with their opponents, the abductors. Abductors are again muscle groups that cause the body to lead away movements. If the neuronal impulse to the adductor disturbed, it would lead to the constant Abspreizung of the corresponding limbs. An approximately permanently abducted leg can not be guided in a straight line when moving forward. It can only be moved in outward arcs.
For the adduction of the leg several thigh muscles are required. In addition to adduction movements, rotational movements are sometimes necessary. The adductor's lodge in the thigh includes the five muscle groups adductor brevis, adductor longus, adductor magnus, gracilis and pectineus. In the interplay of all adductors adduction, rotational movements and diffractions are coordinated with each other.
In addition to the supply of the adductor nervus obturatorius also innervates the hip joint sensitive. Lesions on the obturator nerve can therefore also lead to pain on the inner thigh.
Diseases & complaints
The examination of the adductor reflex should give the doctor information about possible neurological diseases. The reflex response depends both on the excitement of the motor neurons and on the intact structures involved in the reflex arc. So it comes after a stroke often to an increase in muscle reflexes, which is noticeable in a spasticity. In this context, reflex twitches in the neighboring muscle groups are triggered. These are noticeable as extraneous reflections.
A weakening of the muscle reflex is triggered by mechanical or inflammatory processes in the corresponding reflex arc. In the case of adductors, this can lead to a permanent slight spreading of the limbs. Thus, paralysis of the obturator nerve can occur, which usually arise during childbirth. The passage of the fetus through the pelvis sometimes presses the nerve against the inner pelvic wall, damaging it. This is especially the case when the birth canal is too narrow.
Also in the surgical removal of lymph nodes in cancer, lesions of the obturator nerve may rarely occur. The paralysis is expressed in a lateral spreading of a leg. The leg can no longer be attached to the body and is dragged along with the forward movement only by lateral bow movements. In extreme cases, it can also laterally ausgrätschen.
There are also situations in which a nerve obturator nerve blockage must occur. This is a regional anesthetic procedure for a bladder operation. If, for example, electrocautery is required to remove bladder tissue, the obturator nerve must be immobilized, as it runs directly on the outer wall of the bladder. The electrical stimulation would cause the adductor muscles to reflexively contract. As a result, a bladder perforation could occur through the resectoscope.
To immobilize the obturator nerve, a local anesthetic is injected at the adductor muscle insertion of the pubic bone. Nervus obturator nerve block can also be used for hip pain or adductor spasm conditions.
Pain in the thigh can have many causes. Damage to the obturator nerve causes isolated pain on the inner thighs. Nerve lesions can be caused, among other things, by entrapment of the nerves in a disc herniation or pelvic fracture. To determine whether the adductor pain really caused by a lesion of the nerves, however, requires a comprehensive diagnosis.