What’s the difference between making a small mistake in performance settings and making one in a rehab setting? In performance, it might mean adjusting training focus. In rehab, it could mean re-injury, lost trust, and more time on the sidelines. Knowing when to prioritise precision over significance is critical. Here’s how to refine your assessment strategy.

Precision vs. Significance: what it means

The idea of precision vs. significance, a concept I’ve come across recently whilst working through the Altis Need for Speed course, revolves around balancing the search for a definitive, accurate solution to a complex problem with the need for a pragmatic, actionable decision based on the available information.

In essence, it recognises that chasing certainty is a fallacy. Our solutions to complex problems are approximations of what we know:

• We are limited in our ability to understand highly complex problems.
• We can’t possibly know every facet.
• Our measurement tools have limits.
• We are constrained by time to make decisions.

In performance contexts, this principle makes perfect sense, gather just enough information to make informed, impactful decisions. While performance enhancement and rehab have their complexities, rehab often presents even greater challenges. The stakes higher, the margins for error smaller.

Under performance settings, a slightly wrong decision might be insignificant. However, in rehab, even minor missteps can lead to meaningful consequences.

Do we have the insight we need?

Understanding an athlete's capabilities begins with asking the right questions: Do we understand all components of the athlete, or are we missing critical insights?

Imagine you’ve profiled a healthy athlete across a series of assessments and determined a need to increase maximal force production. You develop and execute a program to address this, but later find that the improvements in maximal strength didn’t transfer to other tasks. The conclusion? Maximal force production wasn’t the key, but apart from a loss of time, no harm done.

Now consider an athlete rehabbing from a hamstring strain. After a series of assessments, you decide their capacity is sufficient to progress running speeds. However, they soon experience a recurrence. Not only are you back to square one, but the athlete’s trust and timeline have taken a significant hit.

Approximations may suffice in performance contexts, but in rehab precision becomes paramount and small errors can have lasting consequences.

Too many assessments: the hidden danger

Every metric in your assessment battery represents potential insights but also carries the risk of statistical errors. Even outside of research settings, we need to be aware of the validity and reliability of our assessments. One aspect of this is understanding Type I and II Errors.

Imagine a car’s temperature gauge falsely signaling overheating (a False Positive or Type I error). If we misinterpret these results and act on this non-existent issue, implementing unnecessary interventions, we have essentially wasted valuable resources without addressing a real problem.

Conversely, imagine the faulty temperature gauge fails to warn us of engine overheating (a False Negative or Type II error), and we miss a genuine problem (an undetected strength imbalance, for example). Picture a mechanic ignoring a subtle engine issue that eventually leads to a breakdown. In the context of assessments, these oversights can be costly, especially in rehab settings.

The more assessments and the more metrics each assessment provides, the greater the likelihood of encountering False Positives and False Negatives. Balancing precision with efficiency in assessment design is key.

Performance testing vs. Rehab assessment: why it matters

Performance testing provides broad insights into an athlete’s capabilities, measuring attributes like speed, power, and strength to guide training. Here, significance is key. You need just enough data to make decisions without unnecessary complexity.

Rehab assessments, on the other hand, demand greater precision. Small asymmetries, weaknesses, or compensations could mean the difference between a successful return to play and re-injury.

And asymmetries are often task specific and thus multiple overlapping assessments may be required to identify patterns and ensure no critical deficits are missed. Take the athlete rehabbing from a hamstring strain as an example. In rehab, you’d incorporate multiple assessments of the hamstring and posterior chain, such as maximal eccentric strength and isometric strength at varied joint angles. This redundancy helps confirm findings, validate results, and minimise errors.

As rehab practitioners, our roles require us to weigh the risk-reward of our decisions particularly when determining return-to-play readiness. Efficiency is still vital, but the stakes demand precision.

Knowing when to go deeper requires clarity on:

• The question you seek an answer for.
• Alignment of assessments with objectives.
• Knowing the information each assessment provides.
• Understanding the overlap in each assessment.
• A process for interpreting results.

Video walkthrough: Assessment hierarchies in action

[Watch this Video: A practical example of applying assessment hierarchies to optimise clarity and outcomes. In this video, I’ll show you how I organise assessments to identify key performance metrics, streamline diagnostics, and improve decision-making processes.]

This video highlights how to structure your assessment processes around the following hierarchies:

• Performance
• Performance Assessment
• Diagnostics
• Lifting Strength
• Athletic Competencies
• Clinical

Interpreting results: Systematic questions

It’s not enough to implement the right tests. To truly maximise the value of your assessments, you need to extract the right information as well. The questions below represent a top-down approach to help systematically paint the picture.

This is of upmost importance to ensure we don’t get lost in the data, particularly when dealing with vast numbers of available metrics.

• What indicates better performance in this task?
• What directly relates to the overall outcome?
• What variables optimise the determining factor?
• Is there an optimal movement strategy, and what metrics reflect it?
• Are there relationships between this task and others that explain performance?
• Are asymmetries task-specific or consistent across overlapping assessments?
• What additional assessments could provide deeper insights?

To illustrate let’s use the example of interpreting performance in a countermovement jump.

• What indicates better performance in this task? Greater jump height
• What directly relates to the overall outcome? The total net positive impulse applied
• What variables optimise the determining factor? Phases specific rates of force development, peak and mean forces, and the time over which they are applied
• Is there an optimal movement strategy, and what metrics reflect it? Strategy is highly indvidual and is chosen (self-selected) based on contextual factors but generally a shorter contraction time and shallower countermovement depth represents a more optimal strategy for a given output (i.e. given Jump Height).
• Are there relationships between this task and others that explain performance? Yes, generally enhanced lower body power, reflected in greater jump heights, has a relationship with better performance in other ballistic tasks where overcoming the body’s inertia is critical (i.e. acceleration, deceleration, change of direction)
• Are asymmetries task-specific or consistent across overlapping assessments? Asymmetries seen in countermovement jump strategy should initially be looked at as specific to the task. Further investigation would be warranted to check if asymmetries are also observed in other assessments.
• What additional assessments could provide deeper insights? A range maximal force production asessments (i.e. maximal isometrics or dynamic strength) or other jumping assessments (i.e. squat jump, single leg countermovement jumps etc) can be useful to fully appreciate an athletes’ lower body power capabilities.

The concept of Precision vs. Significance means you won’t need to always answer every layer. The initial questions may provide you enough information to make a pragmatic, actionable decision. But if you require more precision, these questions can help you systematically paint the picture needed.

Or at the very least help you understand the piece of the puzzle you may be yet to find!

Navigating the next steps

Balancing precision and significance in assessment can feel overwhelming. But clarity comes from using simple frameworks to guide your decisions and interpreting results with intent.

As a final thought, our search for precision should not outweigh the need for significance. The real challenge is knowing when you have enough insight to make a practical, actionable decision.

At that point, trust your process. You’ve gathered the best information available to serve your athletes. Now it’s time to act.

And don’t forget: there are limits to how much we can understand in complex systems. Chasing certainty is a likely fools gold. Progress comes from making informed, confident decisions.

That’s it for today.

Now, take a look at your own assessment hierarchies and run through the systematic questions you will use to sharpen your decision-making.

P.S. Here’s How I Can Help You Further:

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