Knee Outcome Measurements: ACL-RSI

The ACL-RSI is a 12-item client-reported outcome measure designed to assess psychological readiness to return to sport after anterior cruciate ligament injury or reconstruction. It includes items related to emotions, confidence in performance and risk appraisal.

Scores are usually converted to a 0–100 scale, where higher scores indicate greater psychological readiness to return to sport. A lower score may suggest greater concern, lower confidence or greater perceived risk, but the ACL-RSI does not confirm readiness, diagnose a problem or determine clearance on its own.

The ACL-RSI is most useful when combined with symptoms, knee function, strength, hop or performance testing, sport demands, confidence, goals, workload exposure and professional judgement.

Introduction

Returning to sport after ACL injury or reconstruction is not only a physical process. Strength, range of motion, hop performance and sport-specific skills matter, but psychological readiness is also important. Some clients may have good physical test results but still feel uncertain, fearful or hesitant about returning to sport. Others may feel confident before their physical capacity is fully prepared.

The ACL-RSI was developed to help measure the psychological impact of returning to sport after ACL injury and reconstruction. It gives professionals a structured way to record how the client feels about returning to sport, rather than relying only on informal conversation.

The scale is practical because it is short, easy to complete and directly relevant to sport participation. It can be used as a baseline measure, repeated during rehabilitation or training, and compared with physical test results. In Measurz, ACL-RSI scores can sit alongside strength tests, hop tests, balance tests, knee outcome measures, symptoms and return-to-sport notes.

Importantly, the ACL-RSI should not be used as a stand-alone clearance tool. A high score does not prove that the client is ready to return to sport, and a low score does not prove that the client cannot progress. The score should support assessment reasoning and shared discussion.

Quick Summary

Outcome measure name: ACL-RSI
Full name: Anterior Cruciate Ligament Return to Sport after Injury scale
Measure type: Client-reported outcome measure
Primary construct: Psychological readiness to return to sport after ACL injury/reconstruction
Number of items: 12
Score range: Usually 0–100
Higher score means: Greater psychological readiness
Lower score means: Lower psychological readiness, greater concern, lower confidence or higher perceived risk
Best used for: ACL injury or ACL reconstruction populations with sport participation goals
Main caution: It does not determine return-to-sport clearance on its own.

What Is the ACL-RSI?

The ACL-RSI is a questionnaire that measures psychological readiness to return to sport after ACL injury or ACL reconstruction.

The standard version includes 12 items. These items are commonly grouped conceptually into three areas:

• Emotions
• Confidence in performance
• Risk appraisal

The client rates each item on an 11-point scale from 0 to 10. The total score is usually converted to a percentage-like score from 0 to 100.

The ACL-RSI is designed to capture thoughts and feelings that may influence return to sport, such as confidence, nervousness, fear of re-injury and belief in knee performance.

It is not a physical performance test. It should be combined with objective measures where relevant.

Why It Is Used

The ACL-RSI is used to support understanding of the psychological side of return to sport.

It may help professionals:

• Record psychological readiness after ACL injury or reconstruction
• Identify confidence or fear-related concerns
• Track readiness over time
• Support return-to-sport conversations
• Compare psychological readiness with physical test results
• Monitor change during training or rehabilitation
• Guide further discussion about goals, concerns and sport demands
• Improve communication between professionals and clients

The ACL-RSI is especially useful when physical test performance and confidence do not match. For example, a client may show improving strength and hop performance but still report low confidence or high fear of re-injury.

What It Measures

The ACL-RSI measures psychological readiness to return to sport.

It may provide insight into:

• Confidence in returning to sport
• Confidence in knee performance
• Fear or concern about re-injury
• Emotional response to return-to-sport situations
• Risk perception
• Readiness to perform sport-specific tasks
• Psychological barriers to participation
• Change in readiness over time

It does not directly measure:

• ACL graft or ligament status
• Knee stability with certainty
• Strength
• Power
• Hop performance
• Movement quality
• Sport skill
• Tissue healing
• Injury risk with certainty
• Whether the client is cleared for sport

Who It Is Useful For

The ACL-RSI is most useful for clients with an ACL injury history who have sport or high-level activity goals.

It may be useful for:

• Field and court sport athletes
• Recreational sport participants
• Competitive athletes after ACL reconstruction
• Clients returning to pivoting, cutting or jumping sports
• Clients who report fear of re-injury
• Clients with confidence concerns
• Clients with performance goals after ACL injury
• Professionals monitoring readiness over time

It is less useful for clients who do not have a return-to-sport goal, although some items may still help guide discussion around confidence and activity participation.

When to Use This Outcome Measure

Consider using ACL-RSI when:

• A client has an ACL injury or ACL reconstruction history
• Return to sport or high-level activity is a goal
• Psychological readiness is relevant
• The client reports fear, hesitation or uncertainty
• You are tracking progress over time
• You want to compare mental readiness with physical test results
• You are preparing return-to-training or return-to-sport discussions

Common use points include:

• Early baseline after return-to-training planning begins
• Mid-stage rehabilitation or training
• Before sport-specific reconditioning
• Before return-to-training decisions
• Before return-to-sport discussions
• During follow-up after return to sport

When Not to Use or When to Be Cautious

Use caution when:

• The client is not aiming to return to sport
• The client has not yet considered sport participation
• The client has difficulty understanding the response scale
• The language version has not been validated for the client’s language or culture
• The client is highly distressed and needs broader professional support
• The score is being used without physical assessment findings
• The score is being treated as a clearance threshold

The ACL-RSI should not be used to tell a client they are safe or unsafe to return to sport. It should be used to support discussion and monitoring.

Equipment or Resources Required

You need:

• ACL-RSI questionnaire
• Scoring instructions
• Measurz app
• Time to complete, usually only a few minutes
• Optional digital form or printed questionnaire
• Related physical testing results where available

Helpful related Measurz records include:

• Knee pain score
• Knee confidence rating
• Quadriceps and hamstring strength
• Hop tests
• Balance tests
• Movement quality notes
• Sport-specific goals
• Training exposure
• Return-to-sport discussion notes

Administration Protocol / Practice

Setup

Explain that the ACL-RSI asks about confidence, emotions and perceived risk related to returning to sport after ACL injury.

Use the same version each time for repeat testing.

Format

The ACL-RSI is a self-report questionnaire.

The standard form includes 12 items rated from 0 to 10.

Client instructions

A safe instruction is:

“Please answer each item based on how you currently feel about returning to your sport or activity. There are no right or wrong answers. Your responses help us understand your confidence, concerns and readiness so we can track this alongside your physical assessment results.”

Completion method

The client can complete it:

• Digitally
• On paper
• With professional assistance if needed
• As part of a Measurz assessment session

If assistance is provided, record that assistance was given.

Assistance rules

The professional may explain how to use the scale, but should avoid leading the client’s answers.

If the client is unsure about a sport-specific item, relate it to their main target activity.

Missing item handling

Use the scoring method provided by the validated version or official questionnaire source where available.

If an item is missing, avoid guessing. Record the missing item and consider the score incomplete unless the scoring guidance for the specific version allows calculation with missing responses.

Scoring process

Each item is scored from 0 to 10.

The usual total score is calculated by adding the item scores and converting to a 0–100 scale. With 12 items, the raw total ranges from 0 to 120. The converted score is usually:

Raw total divided by 120, multiplied by 100.

Higher scores indicate greater psychological readiness.

Retesting considerations

Retest using the same version and similar context.

Record:

• Time since injury or surgery
• Current training phase
• Sport goal
• Recent flare-ups
• Exposure to sport-specific tasks
• Any major changes in confidence or symptoms

Safety notes

ACL-RSI is not physically provocative. The main caution is emotional sensitivity. If the questionnaire raises significant fear, distress or anxiety, record this respectfully and consider whether further professional support is appropriate.

Scoring and Interpretation

Score range

The ACL-RSI is usually scored from 0 to 100.

Subscales

The 12-item scale includes items related to emotions, confidence in performance and risk appraisal. Many professionals use the total score clinically, although research may analyse domains or shorter versions.

Higher and lower score meaning

A higher score may indicate:

• Greater psychological readiness
• More confidence in sport participation
• Lower perceived risk
• Less fear or nervousness
• Greater belief in knee performance

A lower score may indicate:

• Lower psychological readiness
• More fear of re-injury
• Less confidence
• Greater uncertainty
• More perceived risk
• Need for further discussion or support

Calculation method

Add all 12 item scores, divide by the maximum possible score of 120, then multiply by 100.

Categories or cut-offs

Published studies have proposed different cut-offs for return-to-sport prediction or acceptable symptom state, but values vary by population, timing, sport and method. Do not treat a single cut-off as a universal pass/fail threshold.

What a high score may suggest

A high ACL-RSI score may suggest the client feels psychologically ready or more confident about sport participation. It does not prove physical readiness, safe movement, adequate strength or low injury risk.

What a low score may suggest

A low ACL-RSI score may suggest fear, low confidence or concern about returning to sport. It does not prove that the client cannot progress, but it may indicate that confidence and psychological readiness should be discussed.

What the score does not prove

The ACL-RSI does not prove:

• Knee stability
• Tissue healing
• ACL graft status
• Strength symmetry
• Sport skill
• Movement quality
• Injury risk
• Clearance for sport

How to explain the result safely

A safe explanation is:

“Your ACL-RSI score gives us information about how confident and ready you feel about returning to sport. We will use this alongside your symptoms, strength, movement tests, sport goals and training progress rather than using it on its own.”

What the Score May Mean in Different Client Populations

General fitness clients

For general fitness clients, the ACL-RSI may be less sport-specific unless the client is returning to activities that feel similar to sport, such as running, group training, hiking, jumping or gym-based performance.

A lower score may reflect uncertainty about knee confidence rather than competitive sport fear.

Sport and performance clients

For athletes, the ACL-RSI may be highly relevant because sport often involves speed, contact, cutting, pivoting, jumping and unpredictable environments.

A score may be influenced by previous injury experience, competition pressure, team selection, confidence in the knee and exposure to sport-specific training.

Older adults

For older adults, ACL-RSI may be less relevant unless the person has a clear return-to-sport or high-level activity goal. Interpretation should consider goals, activity expectations and confidence in daily or recreational tasks.

Youth clients

Youth athletes may need age-appropriate explanation and support. A score may be influenced by parent expectations, coach pressure, team identity and understanding of the questionnaire. Use validated youth or language versions where available.

Clients returning after injury

For clients returning after ACL injury or reconstruction, repeated ACL-RSI scores can help track confidence and readiness over time. A single score is less useful than change across stages.

Clients with persistent symptoms

Persistent pain, swelling, giving-way sensations or low confidence may lower ACL-RSI scores. Interpretation should include both physical and psychological contributors.

Workplace or occupational populations

ACL-RSI is not primarily a work outcome measure. If the client’s main goal is work rather than sport, consider a more relevant functional outcome measure and use ACL-RSI only if sport or high-demand activity is also relevant.

Meaningful Change, MCID, MDC and Responsiveness

ACL-RSI responsiveness and meaningful-change evidence continues to develop.

Recent studies have examined ACL-RSI responsiveness and thresholds such as MCID, MIC and PASS after ACL reconstruction. These values can vary depending on timing, population, baseline score, sport level, anchor method and follow-up period.

MCID / MIC

Some recent research has reported MCID or MIC thresholds for ACL-RSI after ACL reconstruction, but values should be matched carefully to the population and timeframe studied. Do not apply one value universally.

MDC and SEM

MDC and SEM values are less consistently reported than reliability and validity measures. Where a study provides MDC or SEM for the exact version and population, use that value for that context.

Responsiveness

Evidence supports ACL-RSI as responsive to change in psychological readiness over time after ACL injury or reconstruction, but responsiveness depends on stage, sport exposure and recovery context.

Practical interpretation

Reported meaningful-change values vary across populations and methods. Use values that best match the client group, measure version and testing context.

If no directly relevant MCID/MDC/SEM is available for the client’s context, interpretation should rely more heavily on:

• Baseline comparison
• Repeated measurement
• Client goals
• Symptom change
• Confidence change
• Training exposure
• Physical test results
• Professional judgement

Normative Data, Reference Values or Comparative Data

ACL-RSI does not have one universal normative value that applies to all clients.

Reference or comparative values are most useful when matched to:

• Time since ACL injury or reconstruction
• Sport level
• Sex
• Age group
• Return-to-sport status
• Graft or surgical context where relevant
• Language version
• Short versus full version

Systematic review evidence shows ACL-RSI scores are commonly lower earlier after ACL injury/reconstruction and may improve over time, but scores vary widely between individuals.

Practical comparison guidance:

• Compare the client with their own baseline.
• Compare repeated scores at similar recovery stages.
• Interpret alongside sport exposure.
• Review confidence and risk appraisal items, not only the total score.
• Use population-specific research values only when they closely match the client.

ACL-RSI should not be used as a strict pass/fail benchmark.

Reliability and Validity

The ACL-RSI has been studied across ACL reconstruction and sport populations and is generally considered a reliable and valid measure of psychological readiness to return to sport.

Evidence supports:

• Internal consistency of the total scale
• Construct validity with related psychological and functional constructs
• Association with return-to-sport outcomes
• Responsiveness to change over time
• Cross-cultural validation in several language versions
• Short-form development and validation in some populations

Known limitations include:

• Different versions and translations may perform differently.
• Cut-offs vary across studies.
• High psychological readiness does not prove physical readiness.
• Low readiness may reflect multiple factors, not one single barrier.
• Evidence is strongest in ACL-related sport populations, not all knee conditions.

Common Errors and Limitations

Common errors include:

• Using the score as a clearance decision
• Treating a cut-off as universal
• Ignoring individual item responses
• Comparing different language versions without caution
• Not recording time since surgery or injury
• Not linking the score to sport exposure
• Not combining with physical tests
• Assuming low score means poor motivation
• Assuming high score means low risk

Limitations include:

• Self-report bias
• Sport-specific context may not suit all clients
• Meaningful-change thresholds vary
• Scores may be influenced by recent symptoms or training experiences
• It does not assess physical capacity
• It does not identify the cause of fear or low confidence on its own

Practical Applications

The ACL-RSI can support:

• Return-to-sport discussions
• Psychological readiness monitoring
• Baseline and retest tracking
• Client education
• Sport-specific goal planning
• Team communication
• Progress reporting
• Comparison with strength and hop testing
• Identifying when confidence and physical capacity do not align

It is especially useful when recorded repeatedly in Measurz alongside objective knee assessments.

How to Record This in Measurz

Record:

• Outcome measure name: ACL-RSI
• Version used: 12-item standard version or short version if used
• Total score
• Score range: 0–100
• Direction: higher score indicates greater psychological readiness
• Date completed
• Completion method: digital, paper or interview-assisted
• Sport or activity goal
• Time since injury or surgery
• Current training phase
• Pain score if relevant
• Symptoms such as swelling, giving way or confidence loss
• Item-level concerns where useful
• Missing items
• Assistance provided
• Language/version used
• Baseline comparison
• Retest date
• MCID/MDC comparison where supported by relevant evidence
• Related physical findings such as strength, hop testing and movement quality
• Notes on interpretation
• Further assessment or support notes where appropriate

Recording these details improves repeatability, communication, client education, assessment reasoning, monitoring over time, team consistency and reporting quality.

Related Outcome Measures / Internal Links

• IKDC Subjective Knee Form
• KOOS
• KOOS-ACL
• Knee Self-Efficacy Scale
• Tampa Scale of Kinesiophobia
• Tegner Activity Scale
• Lysholm Knee Score
• Knee Outcome Survey
• Single-leg hop tests
• Quadriceps strength testing
• Hamstring strength testing

FAQs

What does ACL-RSI measure?

It measures psychological readiness to return to sport after ACL injury or reconstruction.

What does a higher ACL-RSI score mean?

A higher score generally indicates greater confidence, lower fear and greater psychological readiness to return to sport.

What does a lower ACL-RSI score mean?

A lower score may indicate fear, lower confidence, higher perceived risk or uncertainty about returning to sport.

Can ACL-RSI clear someone for sport?

No. It should not be used as a stand-alone clearance tool.

How often should ACL-RSI be repeated?

It can be repeated at key stages of training or return-to-sport planning, especially when confidence, symptoms or sport exposure changes.

Is ACL-RSI only for athletes?

It is most relevant for people returning to sport or high-demand activity after ACL injury.

Should individual items be reviewed?

Yes. Item-level responses can help identify whether concerns relate more to emotion, confidence or risk appraisal.

What should ACL-RSI be combined with?

Symptoms, goals, strength testing, hop tests, movement quality, sport-specific exposure and professional judgement.

Key Takeaways

The ACL-RSI measures psychological readiness to return to sport after ACL injury or reconstruction.

Scores usually range from 0 to 100, with higher scores indicating greater readiness.

It includes emotion, confidence and risk appraisal items.

The score does not prove physical readiness or clear someone for sport.

Meaningful-change values vary by population, timing and method.

Measurz recording should include version, score, sport goal, time since injury/surgery, symptoms, physical test findings and retest context.

References

Faleide, A. G. H., Inderhaug, E., Vervaat, W., Breivik, K., Bogen, B. E., Mo, I. F., & Magnussen, L. H. (2021). Anterior cruciate ligament-return to sport after injury scale: Responsiveness and minimal important change. Orthopaedic Journal of Sports Medicine, 9(6), 23259671211031240. https://doi.org/10.1177/23259671211031240

Piussi, R., Beischer, S., Thomeé, R., & others. (2025). Thresholds for minimum clinically important difference, minimal important change and patient acceptable symptom state for the ACL-RSI and Knee Self-Efficacy Scale after ACL reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy.

Sadeqi, M., Klouche, S., Bohu, Y., Herman, S., Lefevre, N., & Gerometta, A. (2018). Progression of the psychological ACL-RSI score and return to sport after anterior cruciate ligament reconstruction: A prospective 2-year follow-up study. Orthopaedic Journal of Sports Medicine, 6(12), 2325967118812819. https://doi.org/10.1177/2325967118812819

Webster, K. E., Feller, J. A., & Lambros, C. (2008). Development and preliminary validation of a scale to measure the psychological impact of returning to sport following anterior cruciate ligament reconstruction surgery. Physical Therapy in Sport, 9(1), 9–15. https://doi.org/10.1016/j.ptsp.2007.09.003

Webster, K. E., Feller, J. A., & others. (2018). Development and validation of a short version of the Anterior Cruciate Ligament Return to Sport after Injury scale. Orthopaedic Journal of Sports Medicine, 6(4), 2325967118763763. https://doi.org/10.1177/2325967118763763