Objective To investigate the ultrasonic anatomy characteristics of pediatric intermuscular groove brachial plexus nerve and the clinical application value of ultrasound guidance in intermuscular groove brachial plexus block.Methods Seventy-five pediatric patients prepared for upper limb operation were enrolled,high-frequency ultrasound was applied to observe the distribution and echo of intermuscular groove brachial plexus nerve,the neural stem diameter and the depth from the skin were measured. Block of th...