Review of Effects of Changing Position & Different Positions on Parameters of H- Reflex.

Background and aim: The aim of this review article is to study the effects of different positions & change of position on parameters of H- reflex. Materials & Methods: changing position influence the excitability of motor neuron pools & can provide some evidence to resolve neurological and biomechanical problems as disk herniation & radiculopathies . One of the methods to assess these changes is H- reflex which described by German neurologist, Hoffman in 1918.It is a monosynaptic reflex with Ia fibers as afferent limb α-motor neurons as efferent limb. To investigate the effects of changing positions on H reflex parameters, different databases, E-journals & thesis have been searched. Result: Different positions & changing position influence different parameters of H-reflex . Conclusion: Different H- reflex Parameters especially amplitude of H- reflex , show a wide range of varieties and this may explain that amplitude of H-reflex is not a reliable parameter.