A flexible supporting membrane is made from a stretchable material formed into a sheet that adjusts itself based on the pressure applied by a patient's knees. The membrane includes: a top edge adapted to be located in a vicinity of the knees of the patient when in use; a bottom edge adapted to be located in a vicinity of the patient's ankles when in use; and a first and second lateral edge extending between the bottom edge and the top edge. The flexible supporting membrane further includes a central section and two peripheral sections extending along the direction defined by the lateral edges between the top edge and the bottom edge of the sheet. The peripheral sections are adapted for each supporting one of the two knees of a patient by yielding to the pressure exerted by the knees and thus forming a knee cradling depression.

A wearable chair may include a foot frame configured to support a foot of a user; a shank link configured to rotatably connect to the foot frame; a connecting link provided in front of the shank link and configured to rotatably connect to the foot frame; a knee link configured to rotatably connect to each of the shank link and the connecting link; and a thigh link configured to extend from the knee link. The foot frame, the shank link, the connecting link, and the knee link constitute a four-bar linkage.

A support structure device is configured to assist a human patient to rise. The support structure includes a tube bent into a shape described by way of a reference frustum such as a four-sided truncated pyramid. Each side of a top rectangular perimeter of the frustum is shorter than a corresponding side of the bottom rectangular perimeter, and each parallel side of a first trapezoidal perimeter of the frustum is shorter than a corresponding parallel side of a second trapezoidal perimeter. The reference frustum has a height between 10 and 18 inches, the top rectangular perimeter has a length between 10 and 16 inches and a width between 6 and 14 inches, and the bottom rectangular perimeter has a length between 12 and 18 inches and a width between 8 and 16 inches.

A wearable chair may include a foot frame configured to support a foot of a user; a shank link configured to rotatably connect to the foot frame; a connecting link provided in front of the shank link and configured to rotatably connect to the foot frame; a knee link configured to rotatably connect to each of the shank link and the connecting link; and a thigh link configured to extend from the knee link. The foot frame, the shank link, the connecting link, and the knee link constitute a four-bar linkage.

A wearable chair may include a foot frame configured to support a foot of a user; a shank link configured to rotatably connect to the foot frame; a connecting link provided in front of the shank link and configured to rotatably connect to the foot frame; a knee link configured to rotatably connect to each of the shank link and the connecting link; and a thigh link configured to extend from the knee link. The foot frame, the shank link, the connecting link, and the knee link constitute a four-bar linkage.

A wearable chair may include a foot frame configured to support a foot of a user; a shank link configured to rotatably connect to the foot frame; a connecting link provided in front of the shank link and configured to rotatably connect to the foot frame; a knee link configured to rotatably connect to each of the shank link and the connecting link; and a thigh link configured to extend from the knee link. The foot frame, the shank link, the connecting link, and the knee link constitute a four-bar linkage.

A flexible supporting membrane is made from a stretchable material formed into a sheet that adjusts itself based on the pressure applied by a patient's knees. The membrane includes: a top edge adapted to be located in a vicinity of the knees of the patient when in use; a bottom edge adapted to be located in a vicinity of the patient's ankles when in use; and a first and second lateral edge extending between the bottom edge and the top edge. The flexible supporting membrane further includes a central section and two peripheral sections extending along the direction defined by the lateral edges between the top edge and the bottom edge of the sheet. The peripheral sections are adapted for each supporting one of the two knees of a patient by yielding to the pressure exerted by the knees and thus forming a knee cradling depression.

A support structure device is configured to assist a human patient to rise. The support structure includes a tube bent into a shape described by way of a reference frustum such as a four-sided truncated pyramid. Each side of a top rectangular perimeter of the frustum is shorter than a corresponding side of the bottom rectangular perimeter, and each parallel side of a first trapezoidal perimeter of the frustum is shorter than a corresponding parallel side of a second trapezoidal perimeter. The reference frustum has a height between 10 and 18 inches, the top rectangular perimeter has a length between 10 and 16 inches and a width between 6 and 14 inches, and the bottom rectangular perimeter has a length between 12 and 18 inches and a width between 8 and 16 inches.

An apparatus is disclosed as having, for example, a frame, a support assembly, and a pivot joint pivotably connected to the frame and the support assembly for positioning in a plurality of modes including, for example, a user in supine, standing, and/or prone positions. The apparatus may be positioned within various ranges that include supine and prone modes without re-configuring the apparatus.