Half of the NFC North selected a running back high in the 2010 draft, which makes this ESPN Insider piece from Football Outsiders especially relevant to us. FO's Bill Barnwell examined the injury history all players drafted in the first three rounds from 2001-09 and found that -- yes -- rookie running backs missed more games because of injuries than any other position group.
You'll need an Insider subscription to view the entire analysis, but I can tell you that Barnwell found that injuries cost running backs an average of 18 percent of their rookie seasons over that time period. Defensive backs were on the top of that list with a 11.0 percent average.
Broadening the investigation, Barnwell found that running backs maintained a similar injury rate over their first three seasons. A snippet of Barnwell's analysis: "[R]unning backs are generally considered the most pro-ready players coming out of the draft, since their responsibilities are relatively limited and the league does a good job of selecting only those backs who have the athleticism to compete at this level. It's clear that running backs are a high-risk, high-reward species as rookies."
These numbers serve as context as we prepare for the Detroit Lions to make rookie Jahvid Best their top runner, as well as for the Minnesota Vikings to weave Toby Gerhart into their backfield rotation. As Barnwell notes, there is no way to predict injuries for any particular player. But this study gives us some quantitative grounds for the generally-accepted belief that running back is the most bruising position in the game. That teams often count on instant impact makes drafting them an interesting paradox.
One thought I once heard from a personnel man: Even with the NFL trending more and more toward the pass, teams need to draft at least one running back every year to keep a volatile position stocked with fresh legs and viable alternatives.