Lymphatic drainage from subcutaneous tissue in the foot and leg in the sitting human

To determine how fast lymph is drained from the foot in the sitting, completely relaxed position, we injected 99mTc-labelled human serum albumin subcutaneously between the first and second toe of both feet in three subjects sitting with legs down. Radioactivity appeared in the calf within the first 30 s, in the thigh within 1 min and in the blood between 2 and 5 min after injection. A scintigram of the calves showed distinct strands of activity. Radioactivity was found in the inguinal lymph nodes and in no other lymph nodes. The radioactivity in the segments of the calf showed rhythmic variations. EMGs showed minimal muscular activity during the examination. We conclude that interstitial fluid is drained by way of the lymphatics against gravity and most probably as a result of the intrinsic contractions of the lymphatics.