Treadmills bad for hamstrings and glutes?

Treadmills are ok for tempo but not speed work. The article implies that you are using TMs for all. Alwin’s originally from Scotland, so he relishes the weather in California and probably wouldn’t miss a chance to get outside, but he might find a way to stay inside if he was back in Scotland!
To involve the hams more you can use an incline, or, on the flat, do straight leg bounding drills intersperced with regular running/jogging.