ORCHARD PARK, N.Y. — There was well-documented screaming this season about the sub-par play of the Buffalo Bills quarterbacks, offensive line, and certainly offensive coordinator Nathaniel Hackett. But perhaps the most disappointing aspect of the moribund Bills’ offense has been the stagnant running game.

That is painfully obvious for the 8-7 Bills as they stumble to the end of their season Sunday at New England ranked 25th in rushing yards.

Last season the Bills rushed for 2,307 yards to rank second in the league behind only Philadelphia. That was their highest single-season total since 1992 when the third Super Bowl team rushed for an NFL-leading 2,436 yards. Given that performance, there were high hopes that, led by Fred Jackson and C.J. Spiller, they could possibly climb that final rung on the ladder and lead the league for the first time since that 1992 season.

Instead, the Bills have been incredibly inept rushing with 1,378 yards. If they don’t surpass 174 yards in Sunday’s season finale against the Patriots, they will finish with their lowest total in a 16-game season, and their worst in any season (excluding the nine-game 1982 strike year) since 1971 when they managed only 1,337 yards in 14 games.

“I don’t have the answers to why we haven’t been able to run the ball the way we’re accustomed to doing,” said Jackson, who leads Buffalo with a mere 467 yards. “We feel like we’re a lot better than what we put out there this year and that’s the reason we’re sitting here frustrated.”

The Bills opened the season with a 193-yard gashing of the weak Bears, but since then they have surpassed 100 yards only six times. They are coming off a game in Oakland where they gained 13 yards on 13 attempts, their worst outing since 1997, and the fourth-worst in team history. No back has reached 100 yards in a game as Jackson’s 71 yards against Green Bay were the high-water mark.

“We haven’t lived up to what we’re capable of doing and what we’ve done the last couple years,” Jackson said. “It was a down year for everybody. You can say it’s the offensive line, you can say it was us and we’re all included in that. We didn’t play well as running backs and they didn’t get the job done as offensive linemen. That’s what we’re going to say, nobody’s hiding from that.”

The line has been a major source of irritation to the offense, particularly the run game. The Bills are weak at guard with Kraig Urbik and Erik Pears, rookie right tackle Seantrel Henderson has endured numerous struggles, center Eric Wood has had a down year, and left tackle Cordy Glenn has been good, not great.

“That’s bad when you consider how high we were on our rushing game coming into the year,” Wood said. “We didn’t do a good enough job up front, C.J. got dinged up and that hurt, Fred got dinged up, but really there’s no excuse other than a lack of execution and a lot of that falls on us up front.”

Spiller has had a nightmarish season. He rushed for only 287 yards in the first six-plus games before breaking his collarbone. He returned last week in Oakland and carried four times for minus-four yards. Jackson was also hurt in that Oct. 19 game against Minnesota and missed only one game, but he has battled injuries all year and is 33 years old, the oldest running back in the NFL. The Bills turned to Boobie Dixon and Bryce Brown, but the results weren’t much better. As a team, the Bills are averaging 3.7 yards per carry and have only six rushing touchdowns.

Without a reliable running game, the Bills’ offense has sputtered because quarterbacks EJ Manuel and Kyle Orton have mostly played below average despite statistics that make it seem like they weren’t so bad. What their numbers don’t show is that Buffalo ranks 31st in red-zone touchdown percentage at 40.8, and its total of 28 offensive touchdowns is tied for seventh-fewest.

“I really think that touchdowns in the red zone was a big thing, it seemed to hurt us all year, not finishing drives,” said tight end Scott Chandler. “We kicked tons of field goals this year, it felt like, and if we turn some of those into touchdowns, some of those games look differently. There’s plays here and there that haunt you.”