A frame assembly of a motion assistance apparatus comprising a back support configured to support a back of a user and a driver to be arranged on one side of a joint of the user, the frame assembly comprising: a first longitudinal member (L1, L11, L12, L13, L4, 1141); a second longitudinal member (L2, L21, L22, L23, L5, 1142); a third longitudinal member (L3, L31, L32, L33, L6, 1143); the third longitudinal member being spaced apart from the first longitudinal member; the second longitudinal member being configured to diagonally connect the first longitudinal member and the third longitudinal member; a plurality of first distance maintaining members (D1, D11, D12, D13, D3, D31, D32, D33, 1149) configured to connect the first longitudinal member and the second longitudinal member; a plurality of second distance maintaining members (D2, D21, D22, D23, D6, 1148) configured to connect the second longitudinal member and the third longitudinal member, the first longitudinal member (L1, L11, L12, L13, L4, 1141) comprises end portions that are configured to be fixed to a first object and a second object, respectively; characterized in that the second longitudinal member (L2, L21, L22, L23, L5, 1142) comprises end portions that are configured to be fixed to the first object and the second object, respectively: the third longitudinal member (L3, L31, L32, L33, L6, 1143) comprises end portions that are configured to be fixed to the first object and the second object, respectively: the first object is defined by the driver of the motion assistance apparatus; the second object is defined by the back support of the motion assistance apparatus; a first end portion of the frame assembly is configured to connect a first end portion of the first longitudinal member (L1, L11, L12, L13, L4, 1141) and a first end portion of the third longitudinal member (L3, L31, L32, L33, L6, 1143) to the driver; a second end portion of the frame assembly is configured to connect a second end portion of the first longitudinal member (L1, L11, L12, L13, L4, 1141) and a second end portion of the third longitudinal member (L3, L31, L32, L33, L6, 1143) to the back support; and an intermediate portion is arranged between the first end portion of the frame assembly and the second end portion of the frame assembly, wherein a stiffness of each of the first end portion of the frame assembly and the second end portion of the frame assembly is greater than a stiffness of the intermediate portion. a first longitudinal member (L1, L11, L12, L13, L4, 1141); a second longitudinal member (L2, L21, L22, L23, L5, 1142); a third longitudinal member (L3, L31, L32, L33, L6, 1143); the third longitudinal member being spaced apart from the first longitudinal member; the second longitudinal member being configured to diagonally connect the first longitudinal member and the third longitudinal member; a plurality of first distance maintaining members (D1, D11, D12, D13, D3, D31, D32, D33, 1149) configured to connect the first longitudinal member and the second longitudinal member; a plurality of second distance maintaining members (D2, D21, D22, D23, D6, 1148) configured to connect the second longitudinal member and the third longitudinal member, the first longitudinal member (L1, L11, L12, L13, L4, 1141) comprises end portions that are configured to be fixed to a first object and a second object, respectively; the second longitudinal member (L2, L21, L22, L23, L5, 1142) comprises end portions that are configured to be fixed to the first object and the second object, respectively: the third longitudinal member (L3, L31, L32, L33, L6, 1143) comprises end portions that are configured to be fixed to the first object and the second object, respectively: the first object is defined by the driver of the motion assistance apparatus; the second object is defined by the back support of the motion assistance apparatus; a first end portion of the frame assembly is configured to connect a first end portion of the first longitudinal member (L1, L11, L12, L13, L4, 1141) and a first end portion of the third longitudinal member (L3, L31, L32, L33, L6, 1143) to the driver; a second end portion of the frame assembly is configured to connect a second end portion of the first longitudinal member (L1, L11, L12, L13, L4, 1141) and a second end portion of the third longitudinal member (L3, L31, L32, L33, L6, 1143) to the back support; and an intermediate portion is arranged between the first end portion of the frame assembly and the second end portion of the frame assembly, wherein a stiffness of each of the first end portion of the frame assembly and the second end portion of the frame assembly is greater than a stiffness of the intermediate portion.