Our run game dropped off with the disappearance of Ozigbo. When your O line is not able to blow holes for your 'scat' or smaller types backs, then you have to go with a big power back and use a powerful blocking FB as well. We did much better last season down the stretch with Devine and Cross and Jano. I don't think the O line was all that much better last year - rather it was the backfield set up and utilization that helped. If we are going to run the ball better next year, we are going to have to throw the ball MUCH better so that teams will have to stop the passing game with a dime package or other measures that will weaken their run defensive posture. Presumably we will have some extra bodies by next fall on the line as well. Between linemen hurt and limping, etc and the absence of Ozigbo and Cross and Jano, there was a great deal missing. Add in a gimpy Tommy and Iowa had an easy chore to stop our offense.
Also, when we did have Ozigbo in there, we had the stupidity of Langs calling stretch/boundary plays (the few times this season he did) with Ozigbo, and then going back to the off-tackle running plays with Newby. Those roles should have been reversed, to say the least, and demonstrates that Langsdorf either doesn't care or doesn't understand the running game.
Lansdorf really has problems managing the offensive playcalling from a macro level--he started reverting back to 2015 Langsdorf in the back half of the season in that he would fail to call plays to set up future plays, would get cute with playcalling 3rd and 4th and short situations, and he didn't consistently try to stretch things out and use boundary/option plays. When your OC keeps calling plays that you are getting beat on, his job is to find something that works to give your offense success to build off of. Langsdorf's game is more vertical, and he needs to think horizontal if he intends to succeed here (e.g. a rollout option pass would have done wonders to help a struggling O-Line that couldn't create a pocket and Tommy, as would toss/sweep/option plays with the correct personnel).
And yes, injuries played a part, especially with the offensive line. But some of that goes on the coaches and their philosophy of not subbing offensive linemen during games IMO, as well as their choice to gamble and redshirt the players they did. And that, too, ultimately rests at the feet of the OC and the HC.
Honestly, if 2017's offense isn't significantly better than this year's offense by the end of the season, Riley needs to seriously consider cutting bait with Lansdorf and bringing in a new OC. Because if it isn't going to happen with Langsdorf's kids, it's not going to happen, period.
And BTW, none of this is on the kids. None. I think they played with heart, and considering what a craptacular year this was outside of the confines of Memorial Stadium, it's honestly amazing it took until the Iowa game for them to run out of gas.