A lift mechanism (100; 500; 900), comprising: a base (102; 502; 902); a support column (106; 504; 904) coupled to the base (102; 502; 902); a mounting portion (150; 506; 906) movably coupled to the support column (106; 504; 904); an energy storage member (144; 544; 944) coupled to the support column (106; 504; 904); and a balance mechanism (116; 516; 916) coupled between the energy storage member (144; 544; 944) and the mounting portion (150; 506; 906), and characterised in that the balance mechanism (116; 516; 906) comprises a first cam (124; 924); a second cam (126; 926) rotationally fixed with respect to the first cam (124; 924), and a wheel (120; 520; 920) rotationally fixed with respect to the first cam (124; 924) and the second cam (126; 926) wherein the first cam (124; 924) and the second (126; 926) are configured to convert a variable force exerted by the energy storage member (144; 544; 944) into a substantially constant force applied to the mounting portion (150; 506; 906) via the wheel (120; 520; 920); and wherein the balance mechanism (116; 516; 916) further comprises a pulley system (130; 530; 930), the pulley system comprising a first cam pulley (164; 964) and a second cam pulley (168; 968) that route one or more flexible elements (132; 135; 931; 932) between the first and the second cams (124; 126; 924; 926) and the energy storage member (150; 506; 906); and the lift mechanism (100, 500) further comprising a cam member (200; 550; 950) comprising the first cam (124; 924) and the second cam (126; 926), wherein the first cam, the second cam and the wheel (120; 520; 920) are coaxially mounted to the base (102; 502; 902), wherein the first cam has a radius that varies with rotation and the second cam has a radius that varies with rotation, wherein the first cam and the second cam each comprise an axis of rotation and a cam surface (125, 127) that winds about the axis of rotation, and wherein the radius of each of the first cam and the second cam (124; 126; 924; 926) decreases as the cam surface winds between a perimeter of the cam and the rotational axis of the cam, wherein the decreasing radius is configured to match a variable force profile of the energy storage member (144; 544; 944). a base (102; 502; 902); a support column (106; 504; 904) coupled to the base (102; 502; 902); a mounting portion (150; 506; 906) movably coupled to the support column (106; 504; 904); an energy storage member (144; 544; 944) coupled to the support column (106; 504; 904); and a balance mechanism (116; 516; 916) coupled between the energy storage member (144; 544; 944) and the mounting portion (150; 506; 906), and characterised in that the balance mechanism (116; 516; 906) comprises a first cam (124; 924); a second cam (126; 926) rotationally fixed with respect to the first cam (124; 924), and a wheel (120; 520; 920) rotationally fixed with respect to the first cam (124; 924) and the second cam (126; 926) wherein the first cam (124; 924) and the second (126; 926) are configured to convert a variable force exerted by the energy storage member (144; 544; 944) into a substantially constant force applied to the mounting portion (150; 506; 906) via the wheel (120; 520; 920); and a first cam (124; 924); a second cam (126; 926) rotationally fixed with respect to the first cam (124; 924), and a wheel (120; 520; 920) rotationally fixed with respect to the first cam (124; 924) and the second cam (126; 926) wherein the first cam (124; 924) and the second (126; 926) are configured to convert a variable force exerted by the energy storage member (144; 544; 944) into a substantially constant force applied to the mounting portion (150; 506; 906) via the wheel (120; 520; 920); and wherein the balance mechanism (116; 516; 916) further comprises a pulley system (130; 530; 930), the pulley system comprising a first cam pulley (164; 964) and a second cam pulley (168; 968) that route one or more flexible elements (132; 135; 931; 932) between the first and the second cams (124; 126; 924; 926) and the energy storage member (150; 506; 906); and the lift mechanism (100, 500) further comprising a cam member (200; 550; 950) comprising the first cam (124; 924) and the second cam (126; 926), wherein the first cam, the second cam and the wheel (120; 520; 920) are coaxially mounted to the base (102; 502; 902), wherein the first cam has a radius that varies with rotation and the second cam has a radius that varies with rotation, wherein the first cam and the second cam each comprise an axis of rotation and a cam surface (125, 127) that winds about the axis of rotation, and wherein the radius of each of the first cam and the second cam (124; 126; 924; 926) decreases as the cam surface winds between a perimeter of the cam and the rotational axis of the cam, wherein the decreasing radius is configured to match a variable force profile of the energy storage member (144; 544; 944).