Wait, wait, wait...a couple of things;
1)Anyone here done their medial? Ligaments are pretty tough, it takes a lot of force to damage one, certainly more than PJ Marsh can apply to a joint especially bending it the way it's designed to bend.
2)Yes, we do pull legs a bit in tackles, mostly via PJ and Finch, and I don't think you'll find many Eels fans who aren't pissed off when they do it.
3)The medial ligament is on the medial side of the joint, obviously. That's the inside of the joint for anyone who doesn't know. A medial ligament strain occurs when the knee is bent or twisted laterally (or towards the outside), thus placing unnatural pressure on the medial side of the joint. But PJ pulls the leg back towards the medial side, in a fairly natural bend...so how does Billy get a medial ligament strain on a ligament that, for all intents and purposes, is relaxed by the action of pulling the leg? I don;t think Bellamy and his boys really thought this one through...