Injured runner series: causes of running injuries - part b: previous history of injury
Quick Recap: Load Is the Foundation
In Part A of “Causes of Running Injuries” we established that training load mismanagement is one of the primary drivers of running injuries. We learned how to objectively quantify this by using acute:chronic workload ratios (reminder: session duration in minutes x session intensity = arbitrary units). The ACWR gives us a useful framework for understanding when the body’s capacity to absorb stress is outpaced by the stress being applied. But load alone doesn’t tell the whole story. Two runners can follow the exact same training plan and one gets hurt while the other doesn’t. So what else is going on?
The Strongest Predictor of Future Injury Is Past Injury
This finding shows up consistently across the research literature, for all sports. If you want to know who in a training group is most likely to get hurt this season, the single best predictor isn’t their mileage, their age, or their biomechanics. It’s whether they’ve been hurt before. That’s a striking finding, and it demands an explanation.
There are two main ways to interpret it:
Lens 1: The Injury Never Really Resolved
This is the explanation I find most compelling, and most clinically relevant, because it’s what I see over and over as a PT.
When a runner gets injured and returns to training before fully rehabilitating, something important happens under the surface. The painful structure may have quieted down, but the underlying dysfunction often hasn’t been addressed. This is inevitably true of one of the leading causes of injury in runners: patellofemoral pain (PFP), or runner’s knee. Reduced quadricep strength is a risk factor for the development of PFP as well as patellofemoral osteoarthritis (1). We also know that once folks have acquired PFP, they have a further reduction in quad strength. If a runner waits for anterior knee pain to subside, but doesn’t properly assess their dysfunction (quad strength deficit), they may return to running at high volume and intensity with 5%, 10%, or even 20%+ deficit in quad strength.
This is one example, but this is true of so many things: achilles tendinopathy and calf strength, IT band pain and glute strength, hamstring strain injury and hamstring strength. The list goes on.
The result is a body that has remapped how it distributes load, and the new map has blind spots. Structures that were never designed to, or aren’t conditioned enough to absorb certain forces are now absorbing them routinely. They adapt for a while. Then training ramps up, recovery dips, and the weakest link fails. It looks like a new injury, but often it has roots in the previous injury that was never fully rehabbed.
Meeuwisse’s dynamic recursive model captures this well (2). After injury, the athlete re-enters the training cycle with a potentially altered set of intrinsic risk factors. The predisposed athlete phase looks different now. Whether that difference resolves or persists depends almost entirely on the quality of rehabilitation.
Lens 2: Previous Injury as a Marker, Not a Cause
The second interpretation is more epidemiological in nature, and worth understanding even if it’s less actionable. Some researchers argue that previous injury doesn’t cause future injury so much as it signals an underlying susceptibility. The idea is that certain runners have tissue characteristics, training behaviors, or biomechanical tendencies that made the first injury likely and those same underlying factors make subsequent injuries likely too. The injury wasn’t the problem. It was a symptom of a deeper vulnerability that was always there.
This is the non-causal interpretation, and it has real methodological support. It also has a somewhat fatalistic quality that I think can be misleading in a clinical context.
Why I Lean Toward Lens 1 — and What It Means for You
Both lenses are probably partially true depending on the runner and the injury. But the non-causal framing, taken too far, implies there’s nothing to be done — you’re either injury-prone or you’re not. That hasn’t matched my experience working with runners, or any athlete for that matter.
What I see far more often is incomplete rehabilitation masquerading as full recovery. Pain goes away, the runner goes back to training, or the athlete goes back to sport, and the functional deficits that remain are invisible until they’re not. The research supports this too, comprehensive rehabilitation that restores strength, neuromuscular control, and movement quality, not just symptom resolution, appears to actually reduce future injury risk. That’s a meaningful distinction.
Meeuwisse’s model has a useful framing here. It distinguishes between events that produce adaptation and events that produce maladaptation. Even runs that feel fine are quietly nudging their risk profile in one direction or the other. A previous injury that was well-rehabbed can actually leave a runner more resilient. One that wasn’t can leave a ticking clock.
The Practical Takeaway
If you have an injury history, the question worth asking isn’t “am I pain free?” it is rather “have I restored my function?”. Pain-free is not the same as functional. Strength, mobility, and movement patterns should be assessed, not assumed. Return to running is a process, not a date on a calendar.
In part C, we’ll look at the third major driver of injury — recoverability — which includes sleep, stress, strength, and nutrition. These are the factors that determine whether your body can absorb and adapt to training load, and they interact directly with injury history in ways that most runners don’t fully appreciate. In part D, we will conclude Part II - Causes of RRI by touching on “other causes” pointed to in the research including: nutrition, biomechanics, and sleep.
Thank you for reading!
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