The present invention discloses a plunger rod 104 for use in connection with an injection syringe barrel 102. The plunger rod 104 comprises an elongated rod 114. The elongated rod 114 comprises a proximal end 107 adapted to receive an applied force along an axis 1000. It further comprises a distal end 105 adapted to transmit the applied force along the axis 1000. The plunger rod 104 is adapted to be inserted into a barrel 102 of a syringe 100 extending along the axis 1000. The plunger rod 104 is further adapted to transmit force along the axis 1000 to a plunger stopper 103 disposed within the barrel 102. The plunger rod 104 further comprises a radial spring mechanism 106, 117, 118, 119, 120, adapted to interact with an inner surface of the barrel 102.
