A hinge assembly for an orthotic, prosthetic or rehabilitative device, comprising: a first strut and a second strut pivotally attached to one another at a pivot point; a spline extending in a first direction perpendicularly from the first strut and the second strut and serving as the pivot point for the first strut and the second strut, the spline being rotatably fixed relative to one of the first strut and the second strut; and a torsion spring having a first end and a second end; the other of the first strut and the second strut has a catch extending in the first direction, located radially of the pivot point; characterized in that: in a first configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, the torsion spring applying a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in a first of two opposite rotational directions, and aiding pivotal movement in a second of the opposite rotational directions; and in a second configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, wherein in the second configuration the torsion spring lies in a turned over orientation relative to the first configuration such that the torsion spring applies a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in the second of the opposite rotational directions, and aiding pivotal movement in the first of the opposite rotational directions. a first strut and a second strut pivotally attached to one another at a pivot point; a spline extending in a first direction perpendicularly from the first strut and the second strut and serving as the pivot point for the first strut and the second strut, the spline being rotatably fixed relative to one of the first strut and the second strut; and a torsion spring having a first end and a second end; the other of the first strut and the second strut has a catch extending in the first direction, located radially of the pivot point; characterized in that: in a first configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, the torsion spring applying a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in a first of two opposite rotational directions, and aiding pivotal movement in a second of the opposite rotational directions; and in a second configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, wherein in the second configuration the torsion spring lies in a turned over orientation relative to the first configuration such that the torsion spring applies a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in the second of the opposite rotational directions, and aiding pivotal movement in the first of the opposite rotational directions. in a first configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, the torsion spring applying a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in a first of two opposite rotational directions, and aiding pivotal movement in a second of the opposite rotational directions; and in a second configuration, the first end of the torsion spring is removably attached to the spline and the second end of the torsion spring is removably attached to the catch, wherein in the second configuration the torsion spring lies in a turned over orientation relative to the first configuration such that the torsion spring applies a bias force opposing relative pivotal movement between the first and the second struts (12, 14) in the second of the opposite rotational directions, and aiding pivotal movement in the first of the opposite rotational directions.