Aload sensor assembly for a substrate that supports a subject, the load sensor assembly comprising: at least four substrate support members , wherein each of the four substrate support members comprises: a load bearing member configured to be attached to the substrate at a first end of the load bearing member, wherein the load bearing member defines a cavity and includes a cap at a second end of the load bearing member opposite to the first end of the load bearing member; a base configured to support the load bearing member and to provide contact with a floor; a load sensor between the cap and the base , wherein the load bearing member is configured to adequately support and evenly distribute a load from the substrate to the load sensor ; and a printed circuit board positioned in the cavity defined by the load bearing member, the printed circuit board in communication with the load sensor, wherein the printed circuit board is configured to receive and process data from the load sensor, and wherein the cap is configured to hold the printed circuit board within the cavity, wherein the base , the cap , the load bearing member , and the load sensor are configured to fit together to maintain lateral alignment of the base , the cap , the load bearing member , and the load sensor wherein the load bearing member and the cap are configured to move vertically relative to the base . at least four substrate support members , wherein each of the four substrate support members comprises: a load bearing member configured to be attached to the substrate at a first end of the load bearing member, wherein the load bearing member defines a cavity and includes a cap at a second end of the load bearing member opposite to the first end of the load bearing member; a base configured to support the load bearing member and to provide contact with a floor; a load sensor between the cap and the base , wherein the load bearing member is configured to adequately support and evenly distribute a load from the substrate to the load sensor ; and a printed circuit board positioned in the cavity defined by the load bearing member, the printed circuit board in communication with the load sensor, wherein the printed circuit board is configured to receive and process data from the load sensor, and wherein the cap is configured to hold the printed circuit board within the cavity, a load bearing member configured to be attached to the substrate at a first end of the load bearing member, wherein the load bearing member defines a cavity and includes a cap at a second end of the load bearing member opposite to the first end of the load bearing member; a base configured to support the load bearing member and to provide contact with a floor; a load sensor between the cap and the base , wherein the load bearing member is configured to adequately support and evenly distribute a load from the substrate to the load sensor ; and a printed circuit board positioned in the cavity defined by the load bearing member, the printed circuit board in communication with the load sensor, wherein the printed circuit board is configured to receive and process data from the load sensor, and wherein the cap is configured to hold the printed circuit board within the cavity, wherein the base , the cap , the load bearing member , and the load sensor are configured to fit together to maintain lateral alignment of the base , the cap , the load bearing member , and the load sensor wherein the load bearing member and the cap are configured to move vertically relative to the base . <EOS>