Catch and release: sea cucumbers might put a torn Achilles tendon back together again.(Biomechanics)

When football season Rolls around, a biomechanist's thoughts inevitably turn to connective tissue--and then, of course, to sea cucumbers. Most fans focus on cutbacks, open-field tackles and chop blocks, but I can't help but ponder the common casualties of these maneuvers: anterior cruciate ligaments (of the infamous ACL injury), hamstrings, and Achilles tendons. Anyone who has had to endure an injury in one of those body parts understands why they come to mind. Although tendons and ligaments--generally referred to as connective tissue--do stretch, they aren't nearly as elastic as rubber bands. In fact, they have a distressing tendency to tear or break, and when they do, they are devils to repair.

Sea cucumbers, invertebrate animals of the phylum Echinodermata, might hold out some hope for the afflicted. Although they have no internal skeleton, sea cucumbers and other echinoderms do have a kind of connective tissue, but one whose qualities are quite unlike those of mammalian ligaments and tendons. Biochemists and biomechanists are studying the stuff, known as catch connective tissue, because it might lead to new…