A variable pressure reusable sensor has a first jaw having a first hinge and an emitter and an opposing second jaw having a second hinge and a detector. A pin is disposed through the first and second hinges so as to rotatably attach the first and second jaws. The jaws are adapted to attach to a tissue site so that the emitter transmits optical radiation into the tissue site and the detector receives optical radiation after absorption by the tissue site. A spring having a plurality of legs is disposed around the pin and configured so that the legs apply force to the jaws. A tensioner is disposed proximate at least one of the jaws and configured to variably position at least one of the legs so as to adjust pressure exerted by the jaws on the tissue site.