An apparatus 40 for enhancing venous blood flow through a limb of a subject includes a detachable compression sleeve 41 extendable around the subject's limb and having a plurality of compressors 43-48 situated next to one another along the sleeve 41. In use, the compressors 43-48 substantially encircle the limb and compress the limb in a continuous cyclical compression sequence to move blood within the limb from the distal end of the sleeve 41 to the proximal end to replicate venous blood flow and to prevent backflow. In particular, as a said first compressor begins to compress the limb, a said second compressor preceding the first compressor in sequence already compresses the limb and continues to compress the limb at least until the first compressor compresses the limb to substantially the same extent as the second compressor, and a said third compressor which precedes the second compressor in sequence ceases to compress the limb.