Wrist Technique
during Median Neurodynamic Testing

One of the most important aspects of applying clinical neurodynamics is technique. Lack of sensitivity and too much force can lead to provocation of symptoms and imprecision can produce the wrong category of response to neurodynamic testing.

For instance, an essential component of diagnosis with neurodynamic tests is structural differentiation. This is when neural tissues are emphasized and the adjacent musculoskeletal tissues in the area of the problem are stabilized. The intention is to focus and direct forces to the neural structures in the area of the problem so that, if the symptoms or physical behaviour change during the differentiation movement, a neural mechanism may be implicated in the response to the test. If the musculoskeletal structures in the area of the problem are moved at the same time as the neurodynamic movement, then the test no longer has any degree of specificity.

For instance, a patient has anterior shoulder pain and the therapist chooses to investigate if there is a neural aspect to this problem, using the MNT1. At the end of the elbow extension component of the test, shoulder pain occurs. At this point, the elbow extension produces increased tension in many structures in the shoulder, including the muscles and tendons, also compressing the joint. So production of pain in the shoulder at this point indicates nothing specific about the neural structures because everything has moved. It is now necessary to perform structural differentiation in which the brachial plexus is moved by use of a body segment that is not intended to produce movement in the musculoskeletal structures in the shoulder region. Since wrist extension has already been applied prior to elbow extension (standard sequence), the wrist movement is released and re-applied so that the tension in the plexus changes. If the symptoms also change (without movement of the shoulder), the neural tissues may be implicated.

Again, an important aspect of neurodynamic testing is precise technique. If the shoulder is moved slightly during the test, any change in symptoms in the shoulder could be mistaken for a neurodynamic mechanism and could produce an error of interpretation, a false positive response. This could in turn direct the patient toward neurodynamic treatment when, in fact, neurodynamics could be excluded with precise technique.

In relation to the technique, there is one very important consideration. The therapist's hand that controls the wrist must be used correctly. Frequently therapists place their thumb on the palm of the patient's hand and use their fingers to control the patient's hand and finger movement (Figure 1). The problem with this technique is that, during the wrist extension/flexion phase of the differentiation, it is very difficult to prevent the proximally-directed compressive forces caused by the wrist extension which invariably reach the shoulder. This produces subtle changes in forces in the shoulder which can pass as far proximally as the cervical spine. Again, this could create a false positive response and may lead the therapist to the erroneous conclusion that the problem has a neural component.

Figure 1 - This prevents control and reduces accuracyFigure 1. Therapist's thumb is placed on the front of the patient's hand. This prevents control of proximal and distal forces during the MNT1 and can reduce the accuracy of structural differentiation.

The Correct Technique and Starting Position for the MNT1

Figure 2 - Correct Technique for the MNT1Figure 2. Correct technique for the MNT1. The therapist's thumb is placed behind the patient's wrist/hand so that equal and opposite forces can be applied, preventing compression up the limb to the shoulder.

Note also that the therapist's index finger extends the patient's thumb.

This helps to apply tension to the motor branch of the median nerve which is also a significant part of the test.

Figure 3 - Starting Position for the MNT1Figure 3. Starting position for the MNT1. Note the position of therapist's distal thumb in preparation for control of proximal/distal forces during structural differentiation.

Figure 4 - The Median Neurodynamic TestFigure 4. The median neurodynamic test, with the therapist placing their thumb behind the patient's wrist to prevent proximo-distal forces from passing toward the shoulder during wrist movements.

For instance, during wrist extension, a natural consequence is often proximal compression of the limb.

To prevent this, distal counter-pressure is applied by the therapist's thumb during wrist extension.