4 Facts About Running Back Injuries

Silver bullets! The idea of silver bullets is nice, isn’t it? Drink activated charcoal and it’ll help you detox (not true by the way). Eat a ton of small meals throughout the day and burn fat (not true either). Draft a quarterback late and win your fantasy league (S/O JJ). Okay that last one is true more often than not, but you catch my drift. Although players like Will Fuller show a consistent pattern of recurrent and similar injuries and earned the skepticism about durability, the same cannot be said about skill players in general. Do we really know when a group of players is prone to injuries? How does this affect the way we draft our fantasy football team? I’ll dive into 4 Facts About Running Back Injuries you need to know before stepping into the fantasy football draft room this summer.

TLDR

  1. Plan for RBs to miss 1-3 Games per season. So, draft extra mid-tier or high-upside running backs, go wide receiver heavy and stash a few rookie/mid-tier running backs, or more seriously consider a handcuff early on in the season.
  2. Concussions and ankle sprains are the most common RB injuries and can occur at any given time. So, a handcuff potentially holds a higher value than the traditional consensus because every game counts. This obviously depends on your league size/bench depth etc.
  3. For running back purposes, high work volumes (300+ carries) do NOT lead to more injuries in but we cannot answer why this is the case.The only conclusions we can draw are that players with 300+ carries actually missed less games than players who had around 150-250 carries in a season. There was no relevant difference in size, or age between these two groups. The conclusion we can draw is to not automatically assume that workload, age, or size are independent predictors of injury. Context matters and there’s no way to tease those variables apart from each other.
  4. For fantasy purposes. Running backs who are 27 or older rarely finish as top 5 PPR RBs. Over the last five NFL seasons, the top five PPR running backs average age looks like this: 28, 25, 24, 23, 24. The oldest RBs in the sample of 275 total players was 28 years old. So, try and roster talented running backs 26 or younger to optimize your ceiling.

Plan for RBs to Miss 1-2 Games per Season

A study from 2004-2014 analyzed NFL running backs and their work volume over a total of 11 NFL seasons. The authors split the 275 running backs into two groups:

Group A: RBs who carried the ball 150-250 times (moderate volume).

Group B: RBs who carried the ball 300+ times (heavy volume).

They tracked each RB for two consecutive seasons, starting with the season when they met one of the above criteria of the groups. From now on, I’ll refer to them as “group A” or “group B”.

It turns out, 62% of all running backs in the study missed, at least one game in the second season they were tracked. Even worse, many of them missed an average of three games in season one of being tracked. That tells us that, regardless of volume, running backs are very likely to miss time due to injuries. For reference, in 2019 seven of the final top 12 running backs in PPR formats missed at least one game. In the case of Dalvin Cook (6th), Alvin Kamara (9th), and Saquon Barkley (10th) it was more than one game.

What’s the action plan here? Well, it depends on the situation and your league settings, but there are a few options to consider:

  1. Draft extra mid-tier or high-upside running backs to use when your starters (likely) go down with injuries.
  2. Draft wide receiver heavy and stash a few rookie/mid-tier running backs.
  3. Seriously consider a handcuff early on in the season.

There’s more than one right answer to most things in life, right? Many analysts don’t recommend that last one, but perhaps we should look at it differently due to the next fact.

 

 

 

Games Missed

 

 

 

 

 

We Can’t Predict When Injuries Will Happen

This is a critical component of 4 Facts About Running Back Injuries. Besides the fact that this study found RBs (and LBs) have the highest incidence of knee surgery in the NFL, our first study concluded that concussions and ankle sprains were the most commonly cited injuries that cause missed time in both group A and group B. This is important to discuss because those injuries unlike tendon ruptures, muscle strains, or “overuse” injuries, are nearly impossible to predict. A concussion can happen on snap 199 in Week 15. Similarly, an ankle sprain can happen in Week 2 (looking at you, Saquon) or in Week 14. The key here is that carrying a handcuff potentially holds a higher value than the current consensus. After all, you can’t win your fantasy football championship without making the playoffs. Every game counts.

High Work Volumes Don’t Necessarily Lead to More Injuries in NFL Running Backs

You might have been vibin’ with me up until this last point, but I promise I’m not crazy. Hear me out, as the numbers don’t lie. Our first study set out with the primary goal of determining whether heavy workloads (300+ carries) lead to more injuries and more missed time compared to moderate workloads (150-250 carries). What they discovered was not expected. Group A missed at least one game during the second season they were tracked about 66% of the time. This is in contrast to only 49% for group B. The researchers also pointed out that age/height/weight/BMI did not significantly impact the difference in missed time between the groups. They were all very comparable. To clarify even further, the players all fell within the following biometric ranges and differences between them were negligible.

  • 22-28 years old
  • 5’8″- 6’1″
  • 207lbs- 243 lbs
  • BMI between 29kg/m^2- 32kg/m^2

You might be saying “well of course if they were injured more, they didn’t get as many carries. Duh.”

However, the difference in carries also was not considered to be “statistically significant” meaning that even after adjusting for the amount of time missed, the math concluded, with 95% certainty, that Group A still would have missed more time compared to Group B during both seasons they were tracked.

An even simpler explanation is that the authors and the stats team ran mathematical simulations with this study over and over…and over and over…and over and over again. They did this until almost every theoretical scenario had been accounted for and Group A still missed more games than Group B.

The key takeaways are this:

  1. We cannot answer why this is the case.
  2. This study does not account for fantasy points or overall productivity.
  3. The only conclusions we can draw are that players with 300+ carries missed less time than players with 150-250 carries and
  4. There was no relevant difference in size, or age between groups.

Again: this does not account for production in real life football or fantasy football. 

For reference, in 2019:

  • Only Derrick Henry and Ezekiel Elliot topped 300 carries.
  • Nick Chubb saw 298 carries
  • Christian McCaffrey had 287 carries.
  • Carlos Hyde, Phillip Lindsay and Miles Sanders all had fewer than 250 carries.

The take away here is simple: when it comes to durability, don’t automatically assume that workload, age, or size are independent predictors of injury, especially if they fall within the ranges I give above. Context matters and there’s no way to tease those variables apart from each other. I know this isn’t a perfect way of evaluating RBs, but 4 Facts About Running Back Injuries is about connecting the dots as best we can.

RBs Who are 27 or Older Rarely Finish as Top 5 PPR RBs

Now, moving away from NFL football and shifting into fantasy football mode.

In the study I mentioned, there was no difference in age between those specific two groups. That means age was not a reason for group B to miss less time. However, the study did not analyze average age of top-finishing running backs. Luckily I have that data (shout out to @fantasyinafew)

Over the last five NFL seasons, the average age of top 12 PPR RBs goes like this:

  • 26
  • 25
  • 24
  • 23
  • 24

Over the last five NFL seasons, the top five PPR running backs looks like this:

  • 28
  • 25
  • 24
  • 23
  • 24

Mark Ingram is the oldest top 12 fantasy RB in 2019 at the age of 29. The next oldest? Derrick Henry at 25. To further drive the point home, in 2015, three RBs who were 27 years old or older, finished in as a top five PPR back. Since 2016, only three RBS of that age have finished as a top five PPR back. It’s not that older RBs can’t have big seasons, but they’re fewer and farther in between compared to the young bucks.

This puts a perfectly neat bow on our study from earlier. The oldest RBs in the sample of 275 was, you guessed it, 28 years old.

The takeaway? Try and roster talented running backs 26 or younger to optimize your ceiling. Is this always the case? No, but we’re playing the probabilities here.

Before you all come after me with flames and pitchforks, please understand I realize the primary study I mention has limitations. In fact, the study itself discusses limitations in the conclusion. Also, please keep in mind that I’m simply delivering the best evidence available on NFL running back health in order to help you make better fantasy football decisions. ELE.

The goal of 4 Facts About Running Back Injuries wasn’t to tell you what to do. It isn’t even to give suggestions Instead, the goal is to provide you with data and point out patterns of what’s most likely  to happen. This is a game of probabilities after all.

 

 

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Edwin Porras, SPT
Edwin Porras, SPT
Final year in my Doctorate of Physical Therapy program. Sports injury analyst and consultant, fantasy football enthusiast. Love of all things analytics. DM for business inquires.

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