Baseline Testing: Useful, But Not the Gold Standard

By Jason M. Matuszak, MD, FAAFP, FAMSSM
Baseline Sports & Performance Medicine

Every concussion is unique — and so is every athlete. That’s why baseline neurocognitive testing can be a helpful addition to a school’s or team’s concussion management program, but it’s not the foundation of one.

Over the years, many programs have invested in computer-based or sideline neurocognitive tests that measure memory, reaction time, and processing speed before a season starts. The idea is straightforward: if an athlete later suffers a concussion, their post-injury performance can be compared to their personal baseline to help guide recovery.

When used appropriately, these tools can offer valuable information. They can help track progress and support return-to-learn and return-to-play decisions. But it’s important to understand what they are — and what they aren’t.

Concussion Is a Clinical Diagnosis

Concussion remains a clinical diagnosis, not a test result.
No computer score, balance test, or eye-tracking system can replace a thorough evaluation by a clinician trained in concussion assessment.

A proper evaluation considers:

• The mechanism of injury

• Immediate and delayed symptoms

• Neurologic and vestibular function

• Cognitive performance

• And most importantly — clinical judgment

That’s why the gold standard for concussion assessment is an in-person examination by a qualified healthcare professional, not any single testing tool.

Where Baseline Testing Helps

When integrated into a larger, evidence-based program, baseline testing can:

• Establish a personalized reference point for post-injury comparison

• Support individualized recovery decisions

• Reinforce athlete education and awareness

• Improve communication between athletes, coaches, and clinicians

For athletes with complex profiles — such as those with ADHD, learning disabilities, or prior concussions — baseline data can sometimes clarify whether post-injury results truly represent new changes.

Where Baseline Testing Falls Short

Baseline testing should never be used as a stand-alone clearance or diagnostic tool.
It has limitations:

• Results can be influenced by effort, fatigue, or distraction

• Test–retest reliability varies across platforms

• Interpretation requires clinical context

• False reassurance (a “normal” score despite ongoing symptoms) can delay recovery

In short: a good test helps guide decisions — it doesn’t make them.

The Right Way to Use Baseline Testing

Think of baseline testing as one piece of a comprehensive concussion management plan, not the plan itself.

That plan should include:

• Preseason education for athletes, parents, and coaches

• Clearly defined sideline recognition and removal protocols

• A structured, clinician-supervised return-to-play process

• Coordination between healthcare providers, athletic trainers, and schools

When these elements work together, athletes get the safest, most effective care possible — with or without baseline testing.

Final Thoughts

Baseline testing can be a valuable adjunct, especially when resources and trained personnel are available.
But the most important factor in concussion care is still the clinical expertise of the person performing the evaluation.

Technology can support decision-making — it just can’t replace clinical judgment.

Guardian Caps: What We Know, What We Don’t, and Where They Fit in Sports Safety

By Jason M. Matuszak, MD, FAAFP, FAMSSM
Baseline Sports & Performance Medicine

Over the past few years, you’ve likely noticed more athletes wearing padded helmet covers — commonly known as Guardian Caps — during practices and, increasingly, games. They’re easy to spot: a soft shell that fits over a football helmet, designed to absorb and disperse impact forces before they reach the head.

The concept is appealing. If a simple add-on can reduce the risk of concussion or repetitive head trauma, it seems like an easy decision. But as with most things in sports medicine, the real answer is more nuanced.

What Are Guardian Caps and How Are They Supposed to Work?

Guardian Caps are lightweight, padded outer shells made from closed-cell foam that attach to the exterior of a football helmet. Their design aims to reduce linear and rotational impact forces by providing an extra layer of energy absorption before the helmet itself deforms.

Laboratory impact testing conducted by the manufacturer and some independent labs has shown that Guardian Caps can reduce measured impact forces by roughly 10–20% in certain conditions. This may help decrease the cumulative stress experienced by the head and neck during repeated contacts — especially in practices, where contact frequency is high.

What the Testing Data Actually Shows

Most of the published data to date comes from laboratory impact testing, not real-world studies. These tests measure force attenuation under controlled conditions — not actual concussion incidence in athletes.

The NFL introduced Guardian Caps during preseason practices in 2022, initially for linemen, tight ends, and linebackers. Their own data showed a roughly 50% reduction in reported concussions during practice for those positions compared to previous years. However, the NFL cautioned that the sample size was small and that other factors — such as practice rules, contact limits, and coaching emphasis — could have influenced the results.

To date, no large, peer-reviewed real-world studies have demonstrated that Guardian Caps independently reduce concussion rates in high school or college athletes. The physics make sense — less force is better than more — but the translation from lab to field remains unproven.

Legal Use in NFHS, NCAA, and NFL

NFHS (High School): Guardian Caps are permitted for practice and competition as long as they are NOCSAE-certified and used according to manufacturer instructions. Some state associations may have additional guidance.

NCAA: Currently allowed for practices, but not universally adopted in games. Teams are responsible for ensuring that helmet integrity and certification are not compromised.

NFL: Required for certain position groups in preseason practices and optional for games. The league continues to collect data and evaluate broader use.

Safety, Maintenance, and Replacement Considerations

Like any piece of protective equipment, Guardian Caps require proper use and upkeep to maintain safety benefits.

• Ensure each cap is securely attached per manufacturer instructions before each session.
• Inspect regularly for rips, cracks, or worn straps that could alter performance.
• Clean with mild soap and water; avoid harsh chemicals that can degrade foam integrity.
• Replace caps when they show visible damage, have compressed padding, or at least every two seasons per manufacturer recommendation.
• The manufacturer warranty typically covers 12 months of normal use against material defects.

Failing to follow these steps can actually increase risk — if the device shifts, detaches, or adds unexpected weight to one side of the helmet.

The Missing Piece: Real-World Concussion Data

While Guardian Caps show promise in reducing impact forces, there’s still a gap between biomechanical data and clinical outcomes. Reducing measured force doesn’t always translate to fewer concussions, since concussions depend on more than impact magnitude — including individual vulnerability, rotational acceleration, and timing.

Until larger, independent studies confirm a meaningful reduction in concussion incidence, it’s best to view Guardian Caps as an adjunctive protection tool, not a guaranteed preventive measure.

Budget Priorities: Where to Invest First

For most schools and organizations, safety budgets are limited. Before investing thousands of dollars in purchasing, maintaining, and replacing Guardian Caps, make sure the core elements of athlete safety are fully funded:

• Certified athletic trainer coverage at all practices and games
• Well-trained staff in concussion recognition and emergency response
• Updated Emergency Action Plans (EAPs) for every venue
• Access to qualified healthcare providers for concussion evaluation
• Education for athletes, parents, and coaches

If those fundamentals are in place — and resources allow — Guardian Caps can be a reasonable secondary safety measure. But without strong systems and trained people behind them, even the best equipment can’t guarantee better outcomes.

Final Thoughts

Guardian Caps may help reduce impact forces, but they don’t eliminate concussion risk — and they shouldn’t replace the basics of sound sports safety. Programs should weigh their potential benefits against cost, maintenance, and current evidence. As more real-world data emerges, their role will become clearer, but for now, they should be viewed as one small piece of a much larger safety picture.