Be ultra careful with the speedwork on the treadmill. The doc I'm seeing thinks my hamstring avulsion may in part be due to that. I guess your foot plant is more forward on the tm, and your body compensates for that and the bringing it back with the next stride. My weakest link in the hip area appears to be my hamstring insertion site, so that took a beating this last training cycle (I had a lot of speed this time around getting ready for Boston). Even though my right was the injury complaint side, I had signal and a tear on my left as well per the MRI.