Review of effects of changing position & different positions on Parameters of H- reflex

The aim of this review article is to study the effects of different positions & change of position on parameters of H- reflex. 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. Different positions & changing position influence different parameters of H-reflex. 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.