Articulation arm link

An articulation arm including a plurality of links, each link including:

• a vertebra, having a first base and a second base;
• two outer axial shoulders, formed on said first base and located on a radial line of said first base and protruding from said first base, each of said two outer axial shoulders including a respective pin hole;
• two inner axial shoulders, formed on said second base and located on a radial line of said second base and protruding from said second base, each of said two inner axial shoulders including a respective pin hole;
• four control bore holes, two of said four control bore holes entering said second base and exiting a respective one of said outer axial shoulders and the other two of said control bore holes entering said first base and exiting a respective one of said inner axial shoulders;
• two pins, each of said pins including a respective pin control bore hole,
• wherein pin holes respective of said two outer axial shoulders are operable to be aligned with pin holes respective of two inner axial shoulders of another link and with respective pins, thereby enabling each of said pins to be inserted through two respective aligned pin holes, thereby creating a bearing between two adjacent links such that said two adjacent links rotate one with respect to the other, and
• wherein said respective pin control bore hole of each said pins is aligned with a respective one of said two control bore holes of each of said link and said another link.