This is a great photo of two very good runners at about the same point in their stride. Meb is a little farther back in his stride than Colleen but that makes it an even better example.
Meb is for sure a good runner but Colleen is much better on the international level.
Note her perfect push for maximum flight with little effort. (about 45 degrees) Upper body weight is perfectly placed to be pushed forward. (slightly back because of slight downhill)
Also the leading leg is following the knee for effortless swing. Her leading leg is at almost the same angle as Abdis. It maintains its "shorter lever" until the moment of release. Meb is "pushing" his leading foot through in an attempt to get a longer stride but effectively shortening it by slowing recovery rate and forward propultion in the air. Note that he is dorsiflexing (body getting ready to strike the ground) while Colleen has not started to yet.
Colleen in getting much more out of her stride and her fitness than Meb is. This is probably a good reason she is still running at the top of her game and able to compete with the best at age 39. Meb is not at the level of the best and with that form never will be. I have seen many pics of meb and have always been suspect of his form but it is so hard to tell from a snapshot but this one has me convinced that he has work to do. I have raced with Colleen a few times (we're about the same speed so I would frequently run right with her in the local 5k's that she would enter) and have had the chance to watch her race as well and have always felt that she had very good form.
Learn from her.
End running form lesson 1.