Abstract

Background: Change in height of the limb not only increases the length of nerve but also causes gradual tapering of nerve with decrease in fiber diameter and myelination. Aim and Objectives: To study the correlation of height with the nerve conduction study (NCS) variables, i. e., latency, duration, amplitude, and conduction velocity of sensory nerve action potential (SNAP) of the sensory nerves of the upper and lower limbs.
Materials and Methods: This is cross-sectional study including 37 participants. After taking consent their age, sex, height, weight, and body mass index were noted. NCS test was carried out for median, ulnar, and sural sensory nerves. Pearson’s correlation coefficient was calculated. P < 0.05 (*) means difference is statistically significant while P < 0.01 (**) is highly significant difference.
Results: Height showed a significant positive correlation with the SNAP latencies of all the sensory nerves: Median sensory (r = 0.704, P < 0.01), ulnar sensory (r = 0.350, P < 0.05), and sural (r = 0.392, P < 0.05). The SNAP duration and amplitude of ulnar and median sensory nerve were negatively correlated with height while that of sural sensory nerve showed insignificant positive correlation with height. However, a significant negative correlation was seen with the SNAP conduction velocity of median sensory (r = −0.740, P < 0.01) and sural sensory (r = −0.701, P < 0.01) nerve. For ulnar sensory nerve, correlation of height and conduction velocity (r = −0.220) was negative but not statistically significant. Overall, height had an inverse correlation with conduction velocity and positive correlation with latency of SNAP. Conclusion: Clinical recognition of this height effect is important as one should not label an individual with mild increase/decrease in peripheral nerve conduction velocity as abnormal which may be solely related to height.