Mayberry's injury

Now, I'm no doctor but someone really needs to explain how Jermane Mayberry can be playing with a torn biceps tendon when Brian Westbrook was unable to late last year. I recall from Westbrook's injury that the arm becomes nearly useless. Obviously, that is a problem for a running back. But it would seem to me, that such an incapacitation would present similar if not greater difficulties for an offensive lineman. I mean, how do you pass block? One handed? Or do they just harness the arm to your torso and Reid's only going to call running plays over Mayberry so he can use his shoulders? I admire Mayberry's toughness and desire to play, but how he is going to play really needs more elaboration.