Identifying the location of nerve entrapment can be very challenging. Even high tech diagnostic tests such as nerve conduction studies are not always reliable in determining the primary location of nerve pathology. Yet, physical examination can be very helpful for locating potential regions of nerve pathology. One of the more effective physical examination methods for evaluating nerve compression and tension pathologies is the slump test.
An Australian physiotherapist named Geoffrey Maitland first described the most commonly used version of the slump test. He found that symptoms from a number of neurological problems could be exaggerated with certain positions that would stretch the involved nerves. This clinical finding eventually developed into a more complex procedure used for evaluation that was named the slump test. It is easy to see where this procedure got its name, as the primary characteristic of it is the slumped position that the client maintains during the test.
The slump test is performed in several successive steps. You should pause after each step to determine if there is either an increase or decrease in any neurological symptoms. The first step of the test is to have the client sitting comfortably on the edge of the treatment table with the arms held behind the back. From this sitting position the client slumps over forward in the upper thoracic region while keeping the head in some degree of extension. The therapist may give some additional overpressure in the upper thoracic region and exaggerate tension on the neural structures in this position.
Next, the client slowly lowers the head into a position of full neck flexion. Again, the therapist may use some additional overpressure to move the client’s head a little farther into full flexion. At this point there is a great deal of tension in the cervical and upper thoracic neurological structures. If there is any problem such as impingement of the brachial plexus or protrusion of a cervical disc onto nerve roots, it is likely that some symptoms will be felt in the upper extremity. Note whether those symptoms follow a particular dermatome or cutaneous nerve innervation pattern.
The third step in the slump test involves the lower extremity. The first two steps increase tension in the upper extremity neural structures. When the subsequent steps are added, the neural structures in the lower extremity are also put under tensile stress and these steps pull on the whole neural network from the opposite end.
In the third step the client actively extends the knee. The knee extension puts tensile stress on the sciatic nerve. The sciatic nerve pulls on its nerve roots, which in turn pull on all the dura mater and the spinal cord. Note that the amount of tension does not have to be severe in order for symptoms to be felt.
Interestingly, if the primary area of neural restriction is in the upper extremity, such as the brachial plexus, the individual may feel upper extremity symptoms increase when the knee extension is added because it pulls on the whole neural network. It is most common, however, that adding knee extension will increase symptoms in the lower extremity as tension is placed on the sciatic nerve and lower neural structures.
Further tension can be placed on the sciatic nerve with the fourth and final step of the slump test. With the knee held in extension the client dorsiflexes the foot. When the foot is dorsiflexed, it pulls more on the sciatic nerve as well. If there is any area of compression or excess tension on neural structures, this maneuver combined with the others will usually cause increased neurological sensations along the distribution of the nerve.
It is not imperative that you complete all the steps of the test. For example, if a client has very strong neurological sensations in the upper extremity after performing just the upper thoracic slump and the neck flexion, that may be sufficient to determine that there is a significant problem there. Addition of the lower extremity tension through knee extension or dorsiflexion of the foot may be too much tension on the system and be too uncomfortable for the client to perform.
When performing each step in the slump test, add the steps slowly. The slump position may aggravate certain neurological problems, such as a herniated lumbar disc pressing on neural structures. It has been found that leaning over in a slumped position produces some of the largest compressive forces on the lumbar vertebrae and they may push the disc against the posterior longitudinal ligament or other neural structures. While this may be the type of problem that you are trying to identify, it is a good idea not to aggravate it any further than necessary.
The slump test is a relatively complex evaluation procedure that can give us a great deal of information about neural components of a soft-tissue pathology. If you would like to see the slump test performed, click on the video link below to see a demonstration and description of the test.