A selective pressure application device (300; 400), comprising: a tip portion (308; 408) having a first three dimensional geometry; an extension portion (302; 402) coupled to the tip portion, the extension portion (302; 402) having a second three dimensional geometry including a length and varying cross-sectional diameters along the length of the extension portion (302; 402), wherein the cross-sectional diameters of some extension portion sections proximate to the tip portion (308; 408) are smaller than the cross-sectional diameters of some extension portion sections distal to the tip portion (308; 408); a base portion coupled to the extension portion (302; 402) at a distal end to the tip portion (308; 408), the base portion having a third three dimensional geometry wherein the base portion is configured to be planted on a surface or ground such that a user, during use, can apply a force to a muscle via the tip portion (308; 408) while the base portion is planted on the surface or ground, the force including an upward component, wherein the base portion includes a pivot (304; 404); and a handle portion coupled to the base portion via a lever arm, wherein the handle portion forms an angle between the handle portion and the surface or ground while the selective pressure device (300; 400) is in a rest position on the surface or ground, wherein the selective pressure application device (300; 400) is configured to, during use, provide pressure in an angle against the muscle when the user lies on the top of the selective pressure application device (300; 400) with the tip portion (308; 408) contacting the muscle of the body of the user, wherein the tip portion (308; 408) is configured to be moved and angled via rotation of the extension portion (302; 402) around pivot (304; 404) to provide the angular pressure to the muscle, characterized in that the handle portion is configured to be pushed downward by the user such as to force the extension portion (302; 402) to rotate about pivot (304; 404), and that the extension portion (302; 402) connects the tip portion (308; 408) and the pivot (304; 404) together in a manner similar to an isosceles triangle, with the tip portion (308; 408) at the top of the triangle, the pivot (304; 404) being one of the bases of the triangle, and a standing leg (303; 403) or a weight extending from the extension portion (302; 402) at the other base of the triangle. a tip portion (308; 408) having a first three dimensional geometry; an extension portion (302; 402) coupled to the tip portion, the extension portion (302; 402) having a second three dimensional geometry including a length and varying cross-sectional diameters along the length of the extension portion (302; 402), wherein the cross-sectional diameters of some extension portion sections proximate to the tip portion (308; 408) are smaller than the cross-sectional diameters of some extension portion sections distal to the tip portion (308; 408); a base portion coupled to the extension portion (302; 402) at a distal end to the tip portion (308; 408), the base portion having a third three dimensional geometry wherein the base portion is configured to be planted on a surface or ground such that a user, during use, can apply a force to a muscle via the tip portion (308; 408) while the base portion is planted on the surface or ground, the force including an upward component, wherein the base portion includes a pivot (304; 404); and a handle portion coupled to the base portion via a lever arm, wherein the handle portion forms an angle between the handle portion and the surface or ground while the selective pressure device (300; 400) is in a rest position on the surface or ground, wherein the selective pressure application device (300; 400) is configured to, during use, provide pressure in an angle against the muscle when the user lies on the top of the selective pressure application device (300; 400) with the tip portion (308; 408) contacting the muscle of the body of the user, wherein the tip portion (308; 408) is configured to be moved and angled via rotation of the extension portion (302; 402) around pivot (304; 404) to provide the angular pressure to the muscle, characterized in that the handle portion is configured to be pushed downward by the user such as to force the extension portion (302; 402) to rotate about pivot (304; 404), and that the extension portion (302; 402) connects the tip portion (308; 408) and the pivot (304; 404) together in a manner similar to an isosceles triangle, with the tip portion (308; 408) at the top of the triangle, the pivot (304; 404) being one of the bases of the triangle, and a standing leg (303; 403) or a weight extending from the extension portion (302; 402) at the other base of the triangle.