Health critical factor in Bengals' 6-0 start

During the Marvin Lewis era in Cincinnati, it's been a rare occurrence when it's possible to associate the words 'healthy' and 'Bengals'.

Whether it be several key players being nicked up to the point of missing games or even a guy like Geno Atkins (ACL tear), Leon Hall (Achilles tear, twice) or Tyler Eifert (dislocated elbow) being knocked out for the year, injuries have constantly plagued the Bengals under Lewis' watch.

That's changed dramatically this season during Cincinnati's 6-0 start. The initial 53-man roster set in the first week of September is now the same one the Bengals have going into the final week of October. The Wall Street Journal did a study of NFL teams since 2005 and which ones have been the healthiest through six weeks of a season.

Since 2005, the Bengals are the ninth team to make it this far into the season without making changes to their Week 1 roster, according to Stats, LLC. The combined record for the nine teams through six games, including the Bengals, is 39-15.

It's a group that features mostly playoff contenders and even an eventual Super Bowl champion, and it's a list the Bengals are part of:

Even in training camp and the preseason, the Bengals were able to avoid many injuries and even fewer to key players. Backup wide receiver James Wright and backup linebacker Marquis Flower both were placed on Injured Reserve before the regular season began, and they're the only two Bengals who are currently on the Bengals' I.R. list through the first six weeks of this season.

As for the Bengals who were injured in the past two seasons, their impact this year while being fully healthy is a big reason why the Bengals are being pegged as a Super Bowl contender. Eifert and Jones have combined for 52 catches for 663 yards and nine scores in just six games after missing essentially all of 2014.

Atkins spent most of 2014 recovering from his 2013 ACL tear that effectively limited him to nine sacks in 25 games from 2013-14. He already has four sacks this season and looks like the All-Pro he was before injury after getting just three sacks in 16 games last season.

There's even A.J. Green, who missed essentially five games last year due to injury. He only had 17 catches for 314 yards and two scores through the first eights weeks of 2014. Green is already up to 35 catches for 531 yards and three scores this year through six weeks.

Health is always going to be a key factor for any playoff contender. While the Bengals may lose some key guys down the stretch, keeping the majority of the top 20-30 players healthy is critical to a team reaching its true potential, something this Bengals team is doing thus far in 2015.