Objective To investigate the clinical value of ring finger latency difference method combined with the second lumbrical muscle-interosseous muscle test for diagnosis of carpal tunnel syndrome. Methods From January 2014 to May 2015, 69 patients was diagnosed as carpal tunnel syndrome (88 limbs) using conventional electrophysio-logical method, ring finger incubation difference comparison method and lumbrical muscle-interosseous muscle exa-
mination method respectively. The positive detection rates of the latter two methods were compared with that of the traditional electrophysiological method. Results Among the 64 limbs of typical cases, 47 limbs showed median nerve electrophysiological abnormalities, 53 limbs had abnormalities by ring finger latency difference method, 55 patients showed abnormalities in lumbrical muscle-interosseous muscle examination, 60 limbs were abnormal in the combination of the three methods. In the 24 limbs of atypical cases, median nerve electrophysiological abnormality occurred in 15 limbs, 21 limbs were abnormal in ring-finger incubation difference comparison method, 20 cases were abnormal by lumbrical muscle-interosseous muscle method, and 22 limbs were abnormal in the combination of the three methods. Conclusions A combination of ring finger incubation difference comparison method and lumbrical muscle-interosseous muscle method can significantly improve the detection rate of carpal tunnel syndrome. It is worthy of clinical application.