 Let's mention quickly about the skeleton triangle itself. This small triangular space that we can see here is the skeleton triangle anteriorly we have the skeletonus anterior muscle. This is the skeleton anterior muscle. Coming from the cervical vertebrae going down and getting inserted onto the skeleton tubercle of the first rib which is behind the clavicle. This is the skeletonus medius muscle. Again coming from the cervical vertebrae going down and getting inserted also on the first rib. So the triangular space between the two is referred to as the skeleton triangle and this was covered by the pre-vertebral layer of deep cervical fascia which has been removed. Passing through the skeleton triangle we have this structure which I picked up here. This is the upper trunk of the brachial plexus formed by the union of the C5 root and the C6 root. The next structure that we see is this is the middle trunk of the brachial plexus formed by the C7 root itself and lower down we can see lower trunk of the brachial plexus. So we have seen the three trunks of the brachial plexus which pass through the skeleton triangle. Between the upper trunk and the middle trunk but before the lower trunk we have this additional structure which also passes through the skeleton triangle and this is the third part of the subclavian artery. So these are all the structures which pass. This skeleton triangle may be responsible for compression of one or more of these structures and that is known as skeleton syndrome. When it compresses it usually compresses the lower trunk of the brachial plexus. Then the patient will have numbness tingling along the distribution all under on the medial side of the arm or it can also compress the subclavian artery itself and then the person will have diminished or absent radial pulse on the distal part of the hand and that is diagnosed by a special test called the Adson's Test. So these are some clinical correlations. Thank you very much for watching. If you have any questions or comments please put them in the comment section below. Dr. Sanjay Sanyal signing out. Anderson is the camera person for a nice day.