Injury and Rehab · · 5 min read

Understanding Injury Part 1: Dynamic Systems Theory

Understanding Injury Part 1: Dynamic Systems Theory

The Injury-Riddled Playoffs Were A Brutal Reminder

Injuries suck. Period.

One moment, an athlete is moving fine; the next moment, something gives.

And it’s often not during a freak accident or huge collision. It’s during the same movements they’ve done a thousand times.

That’s what makes injuries so hard to understand and even harder to prevent.

In the 2024-2025 playoffs:

  • Damian Lillard ruptured his Achilles.
  • Jayson Tatum ruptured his Achilles.
  • Tyrese Haliburton ruptured his Achilles.

These weren’t wild contact plays.

They were routine actions that these athletes have performed thousands of times.

So why did these plays lead to injuries?

Let’s break down the research (1,2) to provide context into the complex and dynamic nature of injury, and why the body can appear to be fine until suddenly, it’s not.

1️⃣
Disclaimer 1: I have worked in the NBA and have been in the locker rooms after season-ending injuries. Those moments hurt and I feel for the players and staff who deal with them.
2️⃣
Disclaimer 2: My dissertation was on injury prediction in the NBA so this is a topic I am familiar with and enjoy discussing.
3️⃣
Disclaimer 3: I don't have all the answers and anybody who claims to have the answers or reduces injuries down to a single factor (or 2) is likely not credible.

Injury Is a System Breaking Down, Not Just One Thing

Dynamic Systems Theory (DST), which views the body as a constantly adapting system composed of interconnected parts, including muscles, tendons, nerves, and the brain, must be applied to understand the complex nature of sports injuries (1).

  • These interconnected parts work together to coordinate movement
  • That coordination is always adjusting based on internal and external “constraints”
  • Over time, stress can build up silently, even if movement looks normal

Instead of thinking of injury as a “cause and effect” (tight calf = Achilles rupture), this model shows how injury can emerge from many small issues that pile up and suddenly connect.

From Micro to Macro Injuries

The connectivity hypothesis bridges the gap between microinjuries and macroinjuries:

  • Small “microinjuries” are normal and often go unnoticed
  • But if recovery is insufficient, they start to cluster
  • Eventually, they become connected, and one last “normal” movement causes a macroinjury

A-C in this figure demonstrates injury connectivity between microinjuries and macroinjuries:

  • A: A few scattered microinjuries (low risk)
  • B: Clusters start forming (moderate risk)
  • C: One last trigger connects them all (injury)
Figure from Pol et al., 2019

Subtle Changes Signal Risk

Before the system breaks, there may be signs

  • Coordination shifts
  • Timing feels off
  • Movements feel less “sharp”

These changes can signal that the system is losing stability (i.e., potentially moving towards injury), even in the absence of pain.

Not Just What, But When

The same sprint session might build resilience one day, and cause injury the next.

  • Fatigue
  • Stress
  • Sleep
  • Emotional state

All of these changes alter how the body responds to the same workload.

That’s what makes injury complex and why context matters.

Ask the Simple Questions

The authors (1) end with something surprisingly practical:

“How do you feel today?”

This one question captures a snapshot of the system—recovery, readiness, motivation, tightness, etc.

When athletes learn to self-monitor, they become partners in preventing overload.

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From Risk Factors to Risk Profiles

Most injury models still focus on individual "risk factors" (like weak hamstrings or poor ankle mobility).

However, a paradigm shift from identifying factors to identifying patterns is needed (2).

Risk profiles reflect the interaction between multiple factors or webs of determinants over time, not any single issue.

The figure below illustrates how an ACL injury can emerge from a different set of determinants in a basketball athlete compared to a ballet dancer.

Figure from Bittencourt et al., 2016

In complex systems, new patterns emerge that can’t be predicted by looking at the parts alone.

  • Your body self-organizes based on constraints and history.
  • Injuries occur when sufficient small changes cause the system to reorganize in a less stable manner.
  • This makes injury inherently unpredictable in a strict cause-and-effect sense; however, patterns can still provide us with useful warning signs.

As the authors put it, "Sports injuries are complex emergent phenomena, produced by interactions among different units (web of determinants), which may produce regularities (risk profile) that prompt the emerging pattern (injury)."

Risk is Part of the Game, Unfortunately

Injuries are an unfortunate part of the game.

While I am not suggesting that we accept it and do nothing about it, I acknowledge the realities of sport.

A favorite quote of mine often comes to mind when discussing injuries in sport:

"A ship is safe in harbor, but that's not what ships are for.” William G. T. Shedd.

Translated to athletes, we can say that athletes are safest on the bench or not playing, but they want to play and compete.

Of course, it is the responsibility of the performance and medical staff to protect players and manage risk, but sometimes the moment requires hard decisions to be made.

High-risk, low-reward situations may not warrant clearance to play (e.g., regular-season game). However, when the reward is high, risk acceptance thresholds may be lowered (e.g., Game 7 of the NBA Finals).

But let me be clear: this isn’t about blaming any player or staff, and playing critic after the fact is lazy and distasteful, as hindsight is always 20/20.

Coach's Takeaways

While injury risk and uncertainty are all complex and part of the game, we can make a few conclusions:

  • Injuries are the result of systems breaking down, not just single errors
  • Small, hidden issues build up before the visible breakdown
  • Context > load—when and how you train matters more than how much
  • Subjective feel is often more sensitive than hard metrics
  • Monitoring coordination changes and interoception may be key to early detection
  • Risk is an inherent part of the game, and while we continue to work on ways to mitigate it, it will never be zero.

Whats Next

Dynamic Systems Theory sets the stage for injury understanding.

In future posts, we will dive into more nuance, including:

  • Influence of Previous Injury
  • Moderators of Injury
  • Workload Management
  • Statistics of Risk
  • The Risky Business of Sport

I hope this was helpful.

Ramsey

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Reference

  1. Pol, R., Hristovski, R., Medina, D., & Balagué, N. (2019). From microscopic to macroscopic sports injuries: Applying the complex dynamic systems approach to sports medicine—a narrative review. British Journal of Sports Medicine.
  2. Bittencourt, N. F. N., Meeuwisse, W. H., Mendonça, L. D., Nettel-Aguirre, A., Ocarino, J. M., & Fonseca, S. T. (2016). Complex systems approach for sports injuries: Moving from risk factor identification to injury pattern recognition—Narrative review and new concept. British Journal of Sports Medicine.

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