Syringe having pivoting arm plunger rod

A syringe assembly comprising:

• a syringe barrel having a first end, a second end, and a sidewall extending between the first end and the second end, the sidewall defining a chamber;
• a stopper;
• a plunger adapter engaged with the stopper, at least a portion of the stopper positioned within the chamber of the syringe barrel, the plunger adapter defining a recessed portion therein, wherein the recessed portion defines a first area and a second area, wherein the first area takes a shape different than that of the second area;
• and
• a plunger rod having a first end pivotally secured to the plunger adapter about a pivot axis, a second end comprising a thumb press having a recessed portion configured to conform to an external surface of the syringe barrel, and an elongate body extending between the first and second ends and defining a cross-section having a constant shape extending an entire length of the plunger rod between the first and second ends, wherein the first end has a shape that is the same as the cross-section of the elongate body, wherein the plunger rod has a pre-use position wherein the second end of the plunger rod is positioned adjacent to the syringe barrel, and a use position wherein the second end of the plunger rod is spaced from the syringe barrel along a longitudinal axis of the syringe barrel,
• wherein, in the use position, the first end is configured to cooperate within the second area of the recessed portion in the plunger adapter to provide multiple surfaces of engagement parallel to the pivot axis and engaging an outer perimeter of the first end.