An adjustable socket system (600; 700) comprising: a distal portion and a proximal portion; an axis and a length extending between the distal and proximal portions (602, 604); and a plurality of struts (608; 708) connected to the distal portion and distributed circumferentially about the axis, the struts (608; 708) at least in part defining a receiving volume (614; 714) adapted to receive a residual limb and movable between an expanded configuration in which at least some of the struts (608; 708) are moved radially outward relative to the axis to loosen the fit of the adjustable socket system (600; 700), and a closed configuration in which at least some of the struts (608; 708) are moved radially inward relative to the expanded configuration to tighten the fit of the adjustable socket system (600; 700); wherein a tightening system (630; 730) is operatively connected to the struts (608; 708) and arranged to tighten and loosen the fit of the adjustable socket system (600; 700) on the residual limb, wherein the tightening system (630; 730) includes a tensioning control mechanism (632; 732) operatively connected to a first area (614A; 714A) of the receiving volume (614; 714) and to a second area (614B; 714B) of the receiving volume (614; 714) above the first area (614A; 714A) along the length of the adjustable socket system (600; 700), the tensioning control mechanism (632; 732) is operable via a single input to proportionally vary loading of the residual limb between the first area (614A; 714A) and the second area (614B; 714B), characterized in that the tightening system includes a first tensioning element attached to the tensioning control mechanism and the first area, and a second tensioning element attached to the tensioning control mechanism and the second area. a distal portion and a proximal portion; an axis and a length extending between the distal and proximal portions (602, 604); and a plurality of struts (608; 708) connected to the distal portion and distributed circumferentially about the axis, the struts (608; 708) at least in part defining a receiving volume (614; 714) adapted to receive a residual limb and movable between an expanded configuration in which at least some of the struts (608; 708) are moved radially outward relative to the axis to loosen the fit of the adjustable socket system (600; 700), and a closed configuration in which at least some of the struts (608; 708) are moved radially inward relative to the expanded configuration to tighten the fit of the adjustable socket system (600; 700); wherein a tightening system (630; 730) is operatively connected to the struts (608; 708) and arranged to tighten and loosen the fit of the adjustable socket system (600; 700) on the residual limb, wherein the tightening system (630; 730) includes a tensioning control mechanism (632; 732) operatively connected to a first area (614A; 714A) of the receiving volume (614; 714) and to a second area (614B; 714B) of the receiving volume (614; 714) above the first area (614A; 714A) along the length of the adjustable socket system (600; 700), the tensioning control mechanism (632; 732) is operable via a single input to proportionally vary loading of the residual limb between the first area (614A; 714A) and the second area (614B; 714B), characterized in that the tightening system includes a first tensioning element attached to the tensioning control mechanism and the first area, and a second tensioning element attached to the tensioning control mechanism and the second area.