 Rotating residents who are participating in the study will be randomly assigned either to perform block under guided approach with the help of needle guidance or free-hand without the needle guidance. All the blocks will be single injection blocks utilizing the in-plane technique for needle insertion which is the usual protocol in our institution. Each resident will be performing one interscalene block with the device and one without the device and one supraclavicular block with device and one without the device. An independent observer will be present during the case and will be responsible for recording the time taken to perform the block, number of times the needle has been redirected and the number of times the needle is reinserted. This observer will also administer the satisfaction questionnaire. Number of time needle is redirected and number of times reinserted is also a self reported assessment by the physician who is performing the block. Efficacy of the block will be assessed by the standard of care practiced at our center. 