An outsole for an article of footwear, the outsole comprising: an outsole body having a ground contact surface (110, 310) and defining grooves (112, 122, 132, 1810, 2110) having a sinusoidal path along the ground contact surface (110, 310), wherein: each groove includes at least one shoulder edge with the ground contact surface, the shoulder edge defining a right angle with a non-radiused corner, each edge defining a length; the grooves (112, 122, 132, 1810, 2110) provide an edge density of between 40 mm/cm 2 and 200 mm/cm 2 and a surface contact ratio of between 40% and 95%; adjacent grooves (112, 122, 132, 1810, 2110) having a sinusoidal path are intersected by a plurality of branch grooves, wherein the plurality of branch grooves are transverse to the adjacent grooves (112, 122, 132, 1810, 2110) having a sinusoidal path, and wherein the plurality of branch grooves extend in a direction substantially parallel to, or at an angle between about 1° and about 45° with respect to, a longitudinal axis of the outsole body; the surface contact ratio is an overall area of the ground contact surface (110, 310) minus an area of the ground contact surface (110, 310) occupied by the grooves (112, 122, 132, 1810, 2110), divided by the overall area of the ground contact surface (110, 310); the edge density is a cumulative length of the edges of the ground contact surface (110, 310) from the grooves within a square centimeter; the grooves (112, 122, 132, 1810 and 2110) have a width (W O, W T, W Q) of 0.1 mm to 1.0 mm; and the outsole body comprises at least one of a rubber having a durometer of between 45 Shore A and 65 Shore A, a rubber having a minimum coefficient of friction of 0.9 and a durometer of between 50 Shore A and 65 Shore A, and a rubber having a minimum coefficient of friction of 1.1 and a durometer of between 50 Shore A and 65 Shore A. each groove includes at least one shoulder edge with the ground contact surface, the shoulder edge defining a right angle with a non-radiused corner, each edge defining a length; the grooves (112, 122, 132, 1810, 2110) provide an edge density of between 40 mm/cm 2 and 200 mm/cm 2 and a surface contact ratio of between 40% and 95%; adjacent grooves (112, 122, 132, 1810, 2110) having a sinusoidal path are intersected by a plurality of branch grooves, wherein the plurality of branch grooves are transverse to the adjacent grooves (112, 122, 132, 1810, 2110) having a sinusoidal path, and wherein the plurality of branch grooves extend in a direction substantially parallel to, or at an angle between about 1° and about 45° with respect to, a longitudinal axis of the outsole body; the surface contact ratio is an overall area of the ground contact surface (110, 310) minus an area of the ground contact surface (110, 310) occupied by the grooves (112, 122, 132, 1810, 2110), divided by the overall area of the ground contact surface (110, 310); the edge density is a cumulative length of the edges of the ground contact surface (110, 310) from the grooves within a square centimeter; the grooves (112, 122, 132, 1810 and 2110) have a width (W O, W T, W Q) of 0.1 mm to 1.0 mm; and the outsole body comprises at least one of a rubber having a durometer of between 45 Shore A and 65 Shore A, a rubber having a minimum coefficient of friction of 0.9 and a durometer of between 50 Shore A and 65 Shore A, and a rubber having a minimum coefficient of friction of 1.1 and a durometer of between 50 Shore A and 65 Shore A.