Neurodynamics/Neural Tension Abnormalities
Neurodynamics is based on the mechanical and physiological interactions with the nervous system. During movement, structures change in linear dimensions, which imposes stress on the peripheral nerve structures. Variations in nerve length occur with movement. The peripheral nervous system is elastic, so it can adapt to movement. Restrictions of the normal mechanics of the nervous system can produce symptoms the restrictions may be from compression or limitations in mobility of the neural tissues). Current or previous (eg scarring) injury/trauma can provoke a neural injury. Some neural tension abnormalities are well recognised (eg tarsal tunnel syndrome, peroneal nerve entrapment), but others just consist of referred pain that may not be in the classic distribution (and is controversial).
Adverse mechanical neural tension is considered present when there is an abnormal response to neurodynamic examination . Neurodynamics is considered a more appropriate term the neural tension . Clinical features may occur at the site if neural tension or at a distant site.
Neurodynamic tests (see Patient Assessment chapter):
• straight leg raise (SLR)
• slump test
Not without controversy as a clinical approach within physiotherapy
• neurodynamic testing indicated for any unusual or vague pain
• consider in differential diagnosis of chronic pain following ankle sprain; plantar heel pain; tarsal tunnel syndrome
• abnormal foot function may cause adverse neural tension (eg first branch of lateral plantar nerve)
Butler (2000) – “When concepts of neurodynamics are new to you, foot disorders are a good place to start. Neurogenic contributions to foot disorders are quite common and are fast and easy to evaluate. It is also a place to challenge some long held diagnostic entities such as heel spur pain”.
• physiotherapy (mobilisation of the ‘nervous system’ - MOTNS) – mobilisation of nervous tissue is often neglected after lower extremity injury
• exercises (self-stretching)