Abstract: A joint orthosis assembly includes a web, an arm unit, a strap unit, and at least one fastening subassembly. The web has three web portions for being wrapped on an upper limb structure, a lower limb structure, and a joint between the upper and lower limb structures, respectively. The arm unit is retained on the web and includes two arms which are pivotally connected, and which are for being disposed at lateral sides of the upper and lower limb structures, respectively. The strap unit includes two straps each being wound about the web to be coupled between the two arms. The fastening subassembly is configured to permit an end of at least one of the straps to be turnably coupled to a corresponding one of arms.