Chapter 11: Neurodynamic Mobility and Mobilization

CHAPTER OBJECTIVES

At the completion of this chapter, the reader will be able to:

1. Summarize the various types of neurodynamic examination and mobilization techniques.

2. Describe the proposed mechanisms behind the neurodynamic examination and mobilization techniques.

3. Apply knowledge of the various neurodynamic mobilization techniques in the planning of a comprehensive rehabilitation program.

4. Recognize abnormal nervous tissue tension manifestations and develop neurodynamic mobilization techniques to treat these abnormalities.

5. Evaluate the effectiveness of a neurodynamic mobilization technique when used as an intervention.

OVERVIEW

Neurodynamics is the study of nervous system mechanics and physiology, and neurodynamic mobility refers to the amount of movement between neural structures and their surrounding interfaces. Neurodynamic mobilization is an intervention that uses manual techniques or exercises to restore the homeostasis in and around the nervous system through mobilization of the nervous system itself or the structures that surround the nervous system.¹

The nervous system is an electrical, chemical, and mechanical structure with continuity between its two subdivisions: the central nervous system (CNS) and peripheral nervous system (PNS; see Chapter. 3). In addition to permitting interneural and intraneural communication throughout the entire network, the nervous system can withstand mechanical stress due to its unique mechanical characteristics. Nervous tissue, a form of connective tissue, is viscoelastic. This viscoelasticity allows the transfer of mechanical stress throughout the nervous system during trunk or limb movements. This adaptation results from spinal cord length changes during movement and the peripheral nerves’ capacity to adapt to different positions. The peripheral nerves adapt through passive movement relative to the surrounding tissue via a gliding apparatus around the nerve trunk. Three mechanisms appear to play an important role in this adaptability²:

• Elongation of the nerve against elastic forces. In normal daily movement, nerves may slide up to 2 cm relative to surrounding tissues and contend with a strain of 10%.

• Longitudinal movement of the nerve trunk.

• An increase and decrease of tissue relaxation at the level of the nerve trunk.

This mechanism’s efficiency partially depends on the loose connective tissue’s capacity around the nerve (adventitia, conjunctiva nervorum, perineurium) to distribute any traction forces over the whole nerve length. An unfavorable rise in traction forces can occur at certain segments if this force distribution is compromised, depending on the anatomic site (see the next section, “Proposed Mechanisms for Neurodynamic Dysfunction”).²

The role of tension on neural tissue pain and dysfunction has been studied for over a century. During this time, several specific tests have been designed to examine the neurological structures for the presence of adaptive shortening and inflammation. The more common of these neurodynamic mobility tests are described in this chapter.

Once detected, any lack of neural mobility that appears to be contributing to a patient’s signs and/or symptoms can be addressed using several neural mobilization techniques once it has been determined that central pain mechanisms (see Chapter 3) are not ...