The Complete Guide to Measuring Constant-Murley Score [With Examples]

Chronic musculoskeletal pain impacts 11.4% to 24% of people worldwide. The Constant Murley Score stands out as one of the most popular tools to evaluate shoulder pathologies and plan treatments.

This detailed scoring system combines both subjective and objective elements. Subjective parameters account for 35 points while objective evaluations make up the remaining 65 points. The Constant-Murley Score looks at four key areas of shoulder function: pain, activities of daily living (ADL), range of motion (ROM), and strength. The score might look simple, but getting reliable results demands precision and standardized methods among different practitioners.

Knowing how to properly use the Constant Murley Shoulder Score can make your clinical decisions better if you work with shoulder patients. Studies reveal that the CMS shows only moderate correlations (0.56 to 0.75) with other shoulder measures. This fact emphasizes the need to understand the right time and method to use this tool. Research also shows that standardized CMS implementations lead to better intraobserver reliability, and experienced practitioners have minimal error margins.

This piece will teach you how to measure and interpret each part of the constant score. You'll learn about common mistakes to avoid and see practical examples of its use in clinical settings.

Understanding the Constant-Murley Score

The Constant-Murley Score (CMS) helps doctors measure how well a shoulder works. Since its creation in 1986, this complete assessment system gives a score out of 100 points. Let me explain why medical professionals find it so useful.

What is the Constant-Murley Score used for?

The CMS works as a tool to check shoulder function in many conditions. It stands out because it combines what patients report with what doctors measure. The system works with shoulder conditions of all types, even when X-rays look normal.

The European Society for Shoulder and Elbow Surgery (ESSES) picked the CMS as their go-to tool for shoulder assessment. Medical teams can track patient improvement, see how treatments work, and compare results between different studies.

Breakdown of the 4 main components

The CMS looks at four key areas that paint a full picture of shoulder function:

• Pain (15 points) - Doctors check pain levels during everyday activities using a visual scale
• Activities of Daily Living (20 points) - Shows how the shoulder affects work, play, sleep, and arm movement
• Range of Motion (40 points) - Measures how far you can move your arm forward, sideways, and rotate it
• Strength (25 points) - Uses a special tool to measure strength when the arm is raised 90 degrees

Patient feedback (pain and daily activities) counts for 35 points. Physical measurements (movement and strength) make up the other 65 points.

Why it's accessible to more people in shoulder assessments

The CMS shines because it mixes patient experience with actual measurements. Patient surveys alone might reflect mental state, but the CMS gives a better view of real shoulder function.

The score matches well with other shoulder tests (correlation coefficients ≥ 0.70). It's also very reliable - different testers get similar results (ICC 0.84-0.87), and the same tester gets consistent scores (ICC 0.95-0.96).

Doctors can finish the test in 5-7 minutes, which fits well into their busy schedules. This mix of thoroughness and speed has made it popular throughout Europe and North America.

How to Measure Each Component of the CMS

The reliability of Constant-Murley Score measurements depends on using standardized techniques for each component. Here's a complete guide to assess all four parameters of this shoulder evaluation tool.

Pain: Using VAS or verbal rating scales

The pain component looks at discomfort during normal activities and adds up to 15 points to the total score. You can use two methods:

A Visual Analog Scale (VAS) works best with an ungraduated line that shows "no pain" and "intolerable pain" at opposite ends. Patients can't see the numerical score as it appears on the scale's back. You could also use a Verbal Rating Scale (VRS) that has four categories: no pain (15 points), mild pain (10 points), moderate pain (5 points), and severe pain (0 points).

Activities of Daily Living (ADL): Functional tasks and scoring

This subjective component looks at daily function and adds up to 20 points. The assessment has:

• Work/occupational limitations (maximum 4 points)
• Recreational activities limitations (maximum 4 points)
• Sleep quality: unaffected (2 points), sometimes disturbed (1 point), always disturbed (0 points)
• Arm positioning ability: up to waist (2 points), xiphoid (4 points), neck (6 points), head (8 points), above head (10 points)

Range of Motion (ROM): Goniometer vs visual estimation

ROM evaluation makes up 40 points spread across four measurements:

1. Forward elevation (10 points): A seated patient needs goniometer measurement, with scores from 0° (0 points) to 151°-180° (10 points)
2. Lateral elevation (10 points): Measurement follows forward elevation method
3. External rotation (10 points): Five hand maneuvers worth 2 points each determine the score
4. Internal rotation (10 points): The highest anatomical landmark reached determines the score (lateral thigh: 0, interscapular region: 10)

Studies comparing goniometric and visual assessment show neither method consistently measures within ±5° of radiographic control measurements. The method choice matters less than standardization.

Strength: Dynamometer use and standard positions

To measure strength accurately (25 points maximum):

The patient's arm should be at 90° abduction in the scapular plane with downward-facing hand. Place a handheld dynamometer at the wrist and record the highest value from three consecutive tries.

Arm position and torso stabilization affect measurements by a lot. Research points to best intraobserver reliability at 90° abduction without torso stabilization. The final torque calculation needs multiplication of raw force value by the lever arm length.

Ensuring Accuracy and Reliability

Getting an accurate picture of shoulder function needs more than just knowing the parts of the Constant-Murley Score (CMS). Yes, it is important to pay attention to every detail that can affect your measurement results.

Standardizing measurement techniques

The original CMS publication didn't give much guidance on making measurements standard, especially when you have to deal with hand positioning, shoulder plane, and strength measurement methods. The European Society for Surgery of the Shoulder and Elbow (ESSSE) later gave an explanation to help make things more consistent. Making protocols standard has become crucial. A study showed that better standardization led to excellent inter-rater reliability (ICC=0.94) with a standard error of measurement of only 4.9 points.

Visual estimation vs goniometry: Pros and cons

Neither visual estimation (VE) nor universal goniometry (UG) can consistently measure within ±5° of radiographic controls. Notwithstanding that, research shows UG measurements are much closer to control measurements for PIP joints. Both methods show similar accuracy for wrist and MCP measurements. Shoulder-specific assessments show VE has similar reliability to UG, with ICC values from 0.87-0.92 versus 0.76-0.91 for UG.

Inter-rater and intra-rater reliability

The CMS shows excellent reliability metrics. Intra-tester reliability scores range from ICC=0.95-0.96, which shows excellent consistency with the same examiner. Inter-tester reliability ranges from ICC=0.84-0.91, showing strong consistency between different examiners. More importantly, the minimal detectable change (MDC95) is about 13-14 points. This is a big deal as it means that differences above this threshold likely show real clinical changes rather than measurement errors[183].

Common sources of error in CMS scoring

The main sources of error come from inconsistent strength measurement techniques, different arm positions during testing, and non-standard ROM assessment protocols. Single pain scales don't capture pain's complexity well. The functional components also lack specificity to particular activities. Where you place measurement devices—either at the deltoid or wrist—can dramatically change your results and shift scores by up to 44 points.

Examples and Use Cases in Clinical Practice

Clinical applications of the Constant Murley Score show how well it works across different shoulder conditions. Let's get into some ground examples that show how doctors use it daily.

Example 1: Post-operative rotator cuff repair

A study of open surgical repair outcomes showed patients' mean Constant score shoulder assessment jumped from 41.7 before surgery to 79.7 after surgery. Small and moderate tears reached final scores of 83.3 and 76.9. Large and massive tears scored 81.9 and 78. This is a big deal as it means that a 10-point improvement shows real clinical progress. Research shows the minimal clinically important difference (MCID) ranges from 9.8 to 19.9 points.

Example 2: Chronic shoulder pain with psychological factors

Psychological factors affect CMS component scores in different ways. The pain parameter takes the biggest hit early on (-0.37, 95% CI: -0.46 to -0.28). Treatment changes this picture as psychological elements start affecting all four CMS parameters, with scores ranging from -0.12 to -0.26. Doctors need to watch these psychological factors closely when they check how well treatments work.

How to interpret changes in CMS over time

You need solid reference points to read these scores right. Scores above 68 are excellent. Good outcomes fall between 57-67. Fair results range from 42-56. Anything below 41 counts as poor. Each condition has its own improvement threshold - rotator cuff calcific tendinitis needs 5.5-9.8 points to show real change.

When to use relative vs absolute CMS

The absolute CMS works on a simple 100-point scale. The relative CMS takes age and gender into account and shows results as percentages of reference values. The individual relative CMS (CSindiv) takes things further by comparing the patient's bad shoulder to their good one. This gives us better accuracy (p=0.004).

Conclusion

The Constant-Murley Score stands out as one of the best tools clinicians can use today to assess shoulder pathologies. This piece explains how this 100-point system combines patient experiences with objective measurements to give a complete evaluation framework.

You can apply this scoring system effectively in your clinical practice by knowing each component—pain assessment, activities of daily living, range of motion, and strength testing. Your measurement techniques will give reliable results when you standardize them, whether you track individual patient progress or compare outcomes across studies.

The CMS works exceptionally well when properly administered, despite no assessment tool being perfect. On top of that, it works for shoulder conditions of all types, from rotator cuff tears to chronic pain presentations. Using either absolute or relative scoring makes it even more useful across different patient populations.

Note that consistent application of measurement protocols leads to accurate results. Take time to become skilled at the standardized techniques outlined here. Your patients will get more precise evaluations, and you'll make better clinical decisions.

The Constant-Murley Score gives you a proven framework that balances completeness with practical clinical use. This applies whether you're starting with shoulder assessments or improving your current approach. As I wrote in this piece, you can use this valuable tool with confidence to boost your shoulder evaluation process and end up improving patient outcomes.

Key Takeaways

Master the essential components and measurement techniques of the Constant-Murley Score to improve your shoulder assessment accuracy and clinical decision-making.

• The CMS combines 4 components: pain (15 points), daily activities (20 points), range of motion (40 points), and strength (25 points) for comprehensive shoulder evaluation.

• Standardized measurement techniques are crucial—proper positioning at 90° abduction and consistent protocols achieve excellent reliability (ICC=0.94).

• Clinical improvement requires score changes exceeding 10-14 points, with excellent outcomes ≥68 points and the assessment taking only 5-7 minutes.

• Use relative CMS for age/gender adjustments and individual relative CMS when comparing affected to unaffected shoulders for greater accuracy.

The CMS balances subjective patient experience with objective measurements, making it the preferred tool of the European Society for Shoulder and Elbow Surgery. When properly administered with standardized techniques, it provides reliable tracking of treatment outcomes across various shoulder pathologies, from rotator cuff repairs to chronic pain conditions.

FAQs

Q1. What is the Constant-Murley Score and what does it measure? The Constant-Murley Score is a comprehensive assessment tool used to evaluate shoulder function. It measures four key components: pain, activities of daily living, range of motion, and strength, providing a total score out of 100 points.

Q2. How long does it take to complete a Constant-Murley Score assessment? A typical Constant-Murley Score assessment can be completed in about 5-7 minutes, making it an efficient tool for clinical settings while still providing comprehensive information about shoulder function.

Q3. What is considered a good Constant-Murley Score? A score of 86-100 points is considered "very good," 71-85 points is "good," 56-70 points is "fair," and below 56 points is considered "poor." An excellent outcome generally corresponds to a score of 68 or higher.

Q4. How reliable is the Constant-Murley Score? When properly administered using standardized techniques, the Constant-Murley Score demonstrates excellent reliability. It has high intra-tester reliability (ICC=0.95-0.96) and strong inter-tester reliability (ICC=0.84-0.91).

Q5. What is the difference between absolute and relative Constant-Murley Scores? The absolute Constant-Murley Score uses a straight 100-point scale, while the relative score adjusts for age and gender, expressing results as percentages of reference values. There's also an individual relative score that compares the affected shoulder to the patient's unaffected shoulder for even greater accuracy.

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