Feature Article - The Sporting Nerve

A key issue with clinical neurodynamics is how to base treatment on the causal mechanisms and patient presentation. For instance, for the same mechanical diagnosis, patients can need a wide range of techniques because of differences in the specific needs of each patient. The treatment for someone with acute severe shoulder pain will need to be different from that of an athlete who only experiences shoulder pain after repeated throwing, even though both may have a similar diagnosis eg. subacromial bursitis. Also, a small mechanical problem for a person who does not use their shoulder very much may not produce many, if any, symptoms. However, such a problem in the sports person could become a major issue, since the sports person has a need for much higher levels of function where the tolerance for subtle dysfunctions is smaller. With that, these aspects are discussed in the context of clinical neurodynamics for shoulder pain in the sports person.

One of the key aspects of selection of treatment for neurodynamic disorders is to select an appropriate physical technique in both diagnosis and treatment. If a patient with acute/severe shoulder pain is treated vigorously, their pain may become provoked and treatment may fail. Conversely if the athlete with a mild, intermittent pain is treated with a very gentle inner range technique, the treatment may not be very effective. So here we discuss a system of grading the patient presentation so that the mechanical technique is appropriate, taking into account pain levels, symptom irritability, level of function and personal needs.

Neurodynamic Testing for the Shoulder

Here we take a sports person with minor symptoms that are produced by repeated movements, such as a throwing or swimming action. For the neurodynamic component, a standard ULNT1 (MNT1) could be performed. However, from clinical experience, people who have very good movement and small and intermittent symptoms often show a normal neurodynamic response (range of motion, symptoms and muscle behaviour), especially when only a standard test is used. Therefore, unless the test emulates the sport person's causal mechanisms, it has the potential to lack sensitivity. This is because standard tests are really only general screening tests and do not always focus specifically on the causal mechanisms. For instance, the MNT1 end range position probably does not reproduce the same muscle actions and joint positions that occur with sports person's specific activity. Since these are often highly specific to the person's sport, it may be necessary to sensitize the evaluation by attempting to reproduce the sports person's postures and dynamic patterns so that nerves can be tested in a situation that is relevant to that particular sports person. Below is a system of technique selection that helps solve the problem of lack of sensitivity in examination and treatment for the athlete.

Progression System for Diagnostic and Treatment Techniques

Shacklock (2005) has categorized neurodynamic techniques in a progressional system that takes into account three aspects: pathophysiology, pathomechanics and nature of the patient presentation. For instance, if a patient experiences a lot of pain that is easily provoked (often expressions of inflammation/pathophysiology), the techniques will need be gentle and limited. In fact, some of neurodynamic test component movements of a standard test can be omitted so that the pain is not provoked. As the patient improves to having less pain and showing higher levels of function, the need for greater specificity in testing increases. The 'big pain/can't-move' patient is considered to be a 'level one patient' in which a limited neurodynamic test is performed. With this, only movements in structures that are remote from the painful structure are performed and the forces in the nerve are slowly built up in the painful area, but very carefully and progressively, usually to the first onset of symptoms, once only. The latter case 'small pain/moves well' is considered to be a 'level 3 patient' whose need is to have a more extensive neurodynamic evaluation and treatment. At this level, there are several categories of techniques that take in account the relevant mechanisms (see Figure 1 below).

There are other classifications of techniques however, below we focus on the two possible ones for this particular article.

Case Examples

A sports person attends your clinic for anterior shoulder pain with throwing. This is the only time the pain occurs. There are no pins and needles, numbness and neurological examination is normal. The error would be to assume that this indicates an absence of neural involvement because the connective tissues of the brachial plexus could produce local pain without producing neurological symptoms or signs. Furthermore, impulse conduction through an area of neuritis can remain normal (Eliav et al 2001). This could come from mechanical irritation rather than compression in which dysfunction in the interfacing tissues (muscles, fascia, joint) could be the cause.

1. The diagnostic test for this problem, after the standard MNT1 is performed and does not reveal sufficient information, could consist of placing the glenohumeral joint in the exact position in which the pain is experienced, then the neurodynamic test can be added to this position (level/type 3c, see Figures 2 and 3). The differentiation movements of wrist extension/flexion and cervical spine contralateral lateral flexion can be performed to ascertain if there is a neurodynamic component to the problem. Treatment could then be directed at any joint or muscle problems in that symptomatic position, with the neurodynamic movements in place. Additionally, the neurodynamic movement could be performed whilst a relevant musculoskeletal structure is in position.

Figure 2Figure 2. Stretch of pectoralis minor muscle during performance of the MNT1 in diagnosis of a small dysfunction in the shoulder, related to muscle and neural tissues. The hand on the shoulder is positioned so the therapist's fingers hook over the front of the acromioclavicular joint and move the scapular into a posterior tilted position, therefore stretching the pectoris minor muscle. At the same time, the MNT1 is performed and the differentiation movements (wrist extension/flexion) are performed to ascertain if a neurodynamic component exists.

Figure 3Figure 3. Assessment technique at level/type 3d (symptomatic position/movement). The patient adopts a throwing position so as to reproduce the mechanism of symptoms. The therapist can refine the shoulder position or resist any chosen movement whilst altering the differentiation movements (wrist flexion/extension and cervical lateral flexion) to detect a hidden neurodynamic component.

You can read more information in Michael Shacklock's text book Clinical Neurodynamics on how to select and perform these techniques or go to our Online Book Shop to purchase a copy. Dr Alf Breig's new Biomechanics of the Nervous System book is also now available for purchase.