Participants were randomly assigned to either an intervention group ( n = 24 ) , who received 808 nm laser irradiation as 4 Jpoint for 20 s over ipsilateral three nerve roots in the cervical region corresponding to C5-C8 vertebrae , and 808 nm laser irradiation as 0.1 Jcm2 for 5 min in a tangential scanning mode over the affected extremity ; or a control group ( n = 24 ) , who underwent the same protocol and timing of laser probe application with the laser switched off .