Thanks for the imput.
I definitely notice my tight hamstrings affecting my hip mobility on every mobility drill that I do. However, they’re already in a lengthened state, and I think it would be unwise to stretch them when they’re already longer than they should be - seems like that could lead to injury. That might explain the recommendation against static hamstring stretching.
When I think about it, it seems like a bad idea for someone with lengthened hamstrings to be stretching them even more, despite the fact that they limit my range of motion. I think maybe it would be a wise idea for me to stick to static stretching for just my hip flexors and rectus femoris, and enhance my hamstring flexibility by trying to achieve greater range of motion on hip mobility drills…
Just think, when you set up to deadlift, or do a single leg RDL style mobility drill, your pelvis is should be set into some anterior tilt simply to maintain neutral spine. I would go as far to say that the hamstrings are great at pulling when the hips are set in anterior tilt - that is how we deadlift after all. The hips do not shift to a posterior tilt until lockout.
To keep it short, stretching your hip flexors is highly unlikely to influence hamstring flexibility. Training for perfect static posture is not very specific to the goal of having enough dynamic mobility to do the exercises you want to do.[/quote]
Actually, in certain cases, stretching the hip flexors can help out with hip mobility in a situation like this. As the OP described, bad posture and long periods of sitting have led to his current problems. When sitting it is your hip flexors that are shortened, and over time, they will be extremely tight from this shortening. To protect against injury, your body will actually start to lock up the antagonist muslces, the hip extensors/hamstrings. They are not tight because they are short, but because they are inhibited by the body. To get rid of this tightness, lengthening the hip flexors may actually help (along with some soft tissue work as well).