A trigger assembly for an automatic medication injection device including a biased drive element and a housing , the biased drive element releasable by operation of the trigger assembly for movement in a first axial direction relative to the housing, the trigger assembly comprising: an actuator including one of a first track and a first follower , the other of said first track and said first follower being fixed in relation to the housing , said first track and first follower arranged for turning said actuator within the housing when said actuator shifts from a first axial position to a second axial position within the housing, said actuator including an interior hollow in which at least one drive element extends; at least one upstanding member extending from the biased drive element toward said actuator, one of said at least one upstanding member and said at least one drive element defining an opening in which fits the other of said at least one upstanding member and said at least one drive element, said at least one upstanding member complementarily shaped with said at least one drive element for said at least one upstanding member, and thereby the biased drive element, to be rotated within said housing when said actuator shifts from said first axial position to said second axial position; and one of a second track and a second follower being fixed in relation to the housing , the other of said second track and second follower on the biased drive element , said second track and second follower structured and arranged to guide the biased drive element when being rotated within said housing when said actuator shifts from said first axial position to said second axial position, and to release the biased drive element for movement in the first axial direction relative to the housing when said actuator reaches said second axial position. an actuator including one of a first track and a first follower , the other of said first track and said first follower being fixed in relation to the housing , said first track and first follower arranged for turning said actuator within the housing when said actuator shifts from a first axial position to a second axial position within the housing, said actuator including an interior hollow in which at least one drive element extends; at least one upstanding member extending from the biased drive element toward said actuator, one of said at least one upstanding member and said at least one drive element defining an opening in which fits the other of said at least one upstanding member and said at least one drive element, said at least one upstanding member complementarily shaped with said at least one drive element for said at least one upstanding member, and thereby the biased drive element, to be rotated within said housing when said actuator shifts from said first axial position to said second axial position; and one of a second track and a second follower being fixed in relation to the housing , the other of said second track and second follower on the biased drive element , said second track and second follower structured and arranged to guide the biased drive element when being rotated within said housing when said actuator shifts from said first axial position to said second axial position, and to release the biased drive element for movement in the first axial direction relative to the housing when said actuator reaches said second axial position. <EOS>