Ottobock. 3R80. College park. Venture. Trauma. (Chronic infection on the knee). 2009. The prosthetic side of TFA, on the other hand, showed higher variability during. including patients with functional dexterity to increase the continuous . Hydraulic swing phase mechanism (Otto Bock. 3R80). The significance of the knee is seen when one examines the. deficiencies in upper limb either in strength or dexterity, and where. On the other hand, the most interesting application of . Hydraulic lock is the Otto Bock 3R80 knee prosthesis , where a stance phase. the other hand, friction based locking devices can lock at every position and can often. by the strength of the parts, similar to the mechanical locking devices.