University of California Los Angeles Shoulder Score

1. Abstract

The University of California Los Angeles (UCLA) Shoulder Score (alternatively designated as the UCLA Shoulder Rating Scale) is one of the most widely implemented hybrid clinimetric and psychometric evaluation instruments in orthopaedic surgery, physical medicine, and musculoskeletal rehabilitation. Originally developed in 1981 by Harlan C. Amstutz and colleagues at the UCLA Department of Orthopaedic Surgery to assess functional outcomes following total shoulder arthroplasty, the instrument was subsequently modified by Ellman and colleagues in 1986 to evaluate outcomes following rotator cuff repair, subacromial decompression, and glenohumeral pathology. The UCLA Shoulder Score integrates patient-reported subjective dimensions with objective clinician-administered physical performance parameters, operationalizing five primary subscales across a single evaluative matrix: Pain (0–10 points), Function (0–10 points), Active Forward Flexion (0–5 points), Strength of Forward Flexion (0–5 points, evaluated via standard manual muscle testing), and Patient Satisfaction (0–5 points). The cumulative composite score ranges from 0 to 35 points, with higher scores reflecting superior functional ability, freedom from symptom burden, and psychological satisfaction; categorical stratification defines scores of 34–35 as excellent, 28–33 as good, and less than 28 as fair or poor.

Psychometrically, the UCLA Shoulder Score exhibits moderate to high internal consistency (Cronbach’s α ranging between 0.78 and 0.89 across varied pathology cohorts) and strong test-retest reliability (intraclass correlation coefficients [ICC] ranging from 0.84 to 0.94). Its convergent and construct validity have been confirmed through significant correlations with widely utilized upper-extremity instruments, such as the Constant-Murley Score, the American Shoulder and Elbow Surgeons (ASES) Shoulder Score, the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure, and the Simple Shoulder Test (SST). Factor-analytic investigations reveal a bifurcated latent structure comprising a distinct patient-reported symptomatic-functional domain and an objective physical-performance impairment domain. This article presents an exhaustive clinimetric and psychometric review of the UCLA Shoulder Score, delineating its historical development, theoretical foundations, measurement properties, structural validity, administrative protocols, and complete authentic scoring inventory.

2. Keywords

UCLA Shoulder Score, UCLA Shoulder Rating Scale, shoulder arthroplasty, rotator cuff repair, clinimetrics, psychometrics, patient-reported outcome measures, musculoskeletal assessment, physical performance testing, forward flexion strength

3. Authors

The UCLA Shoulder Score was originally conceptualized, developed, and published by an interdisciplinary orthopaedic clinical research team at the University of California, Los Angeles (UCLA) School of Medicine:

• Harlan C. Amstutz, MD: Professor and Chairman, Department of Orthopaedic Surgery, UCLA School of Medicine; Chief of Orthopaedic Surgery, UCLA Medical Center, Los Angeles, California, USA. Renowned pioneer in joint arthroplasty, biomechanics, and clinical outcome standardization.
• P. Thomas Sew Hoy, MD: Clinical Fellow and Research Associate in Reconstructive Surgery, Department of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California, USA.
• Ian C. Clarke, PhD: Associate Professor of Orthopaedic Biomechanics and Biomaterials, Department of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California, USA.

In 1986, the instrument underwent significant refinement to improve its discriminative utility in soft-tissue reconstruction, subacromial pathology, and rotator cuff tears by:

• Hyman Ellman, MD: Associate Clinical Professor of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California, USA.
• Garth W. Hanker, MD: Clinical Instructor, Department of Orthopaedic Surgery, UCLA School of Medicine, Los Angeles, California, USA.
• Marcie Bayer, PT: Department of Physical Therapy and Rehabilitation, UCLA Medical Center, Los Angeles, California, USA.

4. Purpose

The primary clinical and psychometric objective of the University of California Los Angeles Shoulder Score is to capture, quantify, and standardize the multidimensional assessment of shoulder joint integrity, symptom severity, and functional recovery following non-operative and surgical interventions. Musculoskeletal disorders of the shoulder girdle—such as glenohumeral osteoarthritis, rotator cuff arthropathy, full-thickness rotator cuff tears, adhesive capsulitis, and impingement syndrome—exert profound disruptive effects on upper-extremity kinematics, activities of daily living (ADLs), vocational performance, and psychological well-being. Historically, orthopaedic assessments prioritized isolated physical examination parameters, such as passive range of motion measured with a goniometer, ignoring the patient’s subjective experience of pain, nocturnal sleep disruption, personal hygiene execution, and perceived satisfaction.

The UCLA Shoulder Score bridges this conceptual divide by operating as a hybrid clinimetric instrument that unifies subjective patient-reported outcome measures (PROMs) with objective clinician-observed physical metrics. Clinically, it provides orthopaedic surgeons, physiatrists, rheumatologists, and physical therapists with a standardized, calibrated numerical baseline against which progressive recovery, therapeutic efficacy, or intervention failure can be quantitatively monitored. Because pre-operative shoulder pathology often impairs high-demand functional domains (e.g., reaching overhead, personal grooming, carrying loads), the tool provides explicit behavioral descriptors for functional disability, anchoring scores to concrete daily milestones (such as dressing, performing hair care, or fastening undergarments).

In research contexts, the UCLA Shoulder Score serves as an established primary or secondary efficacy endpoint in multicenter randomized controlled trials, cohort registries, and comparative clinical effectiveness studies evaluating prosthetic designs (e.g., anatomical versus reverse total shoulder arthroplasty), arthroscopic versus open rotator cuff repairs, biologic augmentation techniques, and post-surgical rehabilitation regimens. By yielding both a continuous interval-like score (ranging from 0 to 35) and categorical ordinal grades (poor, fair, good, excellent), the instrument allows researchers to perform parametric and non-parametric statistical analyses while simultaneously translating empirical findings into meaningful clinical prognostic categories.

5. Psychological Construct

The UCLA Shoulder Score measures the overarching construct of shoulder joint functional integrity and health-related quality of life. Rather than treating physical impairment as an isolated biomechanical anomaly, modern psychometrics and the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) conceptualize musculoskeletal health as an interconnected matrix of physiological functions, anatomical structures, daily activity limitations, and experiential-evaluative satisfaction. The UCLA scale systematically breaks down this overarching construct into five discrete operational dimensions:

1. Pain (Sensory-Affective Symptom Burden)

Pain represents the central driving factor prompting patients with glenohumeral pathology to seek clinical care. In the UCLA instrument, pain is not merely quantified along a generic visual analogue scale of intensity; rather, it is operationalized as an interactive construct combining frequency (continuous vs. occasional), context (at rest vs. during light activity vs. during heavy exertion), and pharmacological reliance (unbearable requiring heavy analgesics vs. tolerable requiring mild nonsteroidal anti-inflammatory agents). This dimension captures the debilitating intrusion of pain into resting baseline states and establishes whether pain functions as a permanent functional barrier or an intermittent, activity-dependent signal.

2. Function (Activity Limitation and Daily Task Execution)

The functional dimension measures the degree of upper-extremity behavioral limitation experienced during essential activities of daily living. It evaluates arm utilization across a continuum extending from complete functional paralysis/disuse (“unable to use arm”) to unrestricted occupational and domestic engagement (“normal activities”). Intermediate intervals systematically assess the performance of light housework, independent dressing and personal hygiene (e.g., washing hair, fastening brassieres), driving motor vehicles, grocery shopping, and engaging in high-plane overhead manual labor. This subscale directly operationalizes the ICF domain of ‘Activities and Participation’, reflecting the person’s functional autonomy within their domestic and social environment.

3. Active Forward Flexion (Kinematic Range of Motion)

This subscale evaluates the active kinematic capacity of the glenohumeral and scapulothoracic joints to elevate the upper extremity in the sagittal plane against gravity. Forward flexion is the fundamental mechanical plane required for human environmental interaction, overhead manipulation, and personal reach. The UCLA instrument categorizes active forward elevation into six stratified angular intervals: <30°, 30°–45°, 45°–90°, 90°–120°, 120°–150°, and >150°. Psychometrically, active motion reflects both motor control and freedom from impingement, contrasting with passive range of motion which assesses capsular compliance alone.

4. Strength of Forward Flexion (Neuromuscular Performance)

Muscular force production in forward elevation evaluates the dynamic integrity of the anterior deltoid, supraspinatus, and stabilizing rotator cuff musculature. Utilizing the standardized Medical Research Council (MRC) manual muscle testing criteria, this subscale records force output on a 0-to-5 ordinal continuum: Grade 0 (no discernible contraction), Grade 1 (trace palpable contraction without joint displacement), Grade 2 (movement with gravity eliminated), Grade 3 (complete active elevation against gravity but zero applied resistance), Grade 4 (active elevation against moderate resistance), and Grade 5 (normal physiological strength against maximal manual resistance). This dimension grounds the instrument in clinical neuromuscular pathophysiology.

5. Patient Satisfaction (Evaluative Psychological Appraisal)

The final dimension introduces an explicit, binary cognitive-affective evaluation of post-treatment status. Musculoskeletal recovery does not always correlate linearly with objective physiological improvements; discrepancies between biomechanical restoration and patient expectations frequently emerge. By providing a weighted, 5-point differential between being “satisfied and better” versus “dissatisfied and worse,” this subscale allows the patient’s subjective appraisal to directly influence whether an intervention outcome is categorized as an overall clinical success or failure.

6. Theoretical Framework

The UCLA Shoulder Score is rooted in the early 1980s transition from pure anatomical-mechanical assessment models toward modern clinimetrics and biopsychosocial health paradigms. Clinimetrics, a term pioneered by clinical epidemiologist Alvan Feinstein in 1987, addresses the science of clinical measurements that integrate distinct symptoms, clinical signs, and laboratory or physical findings into composite indices designed to guide medical decision-making. Historically, orthopaedic assessment was governed by a biomedical model that presumed an unmediated, linear relationship between tissue damage (e.g., the macroscopic size of a supraspinatus tendon tear) and functional disability. However, orthopaedic surgeons repeatedly observed that patients with extensive structural tears sometimes reported mild symptoms, whereas individuals with minimal tissue pathology experienced severe functional disability and psychological distress.

Amstutz, Ellman, and their contemporaries structured the UCLA rating scale around the recognition that complete clinical assessment demands a multi-tiered composite approach. The instrument’s theoretical architecture maps onto three foundational frameworks:

• Feinstein’s Clinimetric Paradigm: Unlike pure psychometric scales that measure a single latent psychological attribute using interchangeable homogeneous items, clinimetric indices intentionally aggregate clinically distinct, heterogeneous phenomena (e.g., pain sensations, physical range of motion, manual muscle strength) into an integrated clinical summary profile. Pain (10 points) and Function (10 points) constitute 57.1% of the total 35-point score, ensuring that patient-perceived functional capacity dominates the clinical outcome profile, while physical examination metrics (Range of Motion, 5 points; Strength, 5 points) prevent subjective over- or under-reporting from distorting the overall evaluation.
• The Biopsychosocial Model of Engel (1977): By incorporating a dedicated 5-point dimension measuring subjective Patient Satisfaction, the UCLA scale acknowledges that psychological appraisal, personal coping, and unmet individual expectations play an active role in clinical recovery. Even if an orthopaedic surgeon restores 160 degrees of forward elevation and Grade 5 strength, persistent subjective dissatisfaction prevents the final score from crossing into the “excellent” category (34–35 points).
• The Disablement Process Model (Verbrugge & Jette, 1994): The UCLA instrument systematically covers the sequential pathways of musculoskeletal disablement: Pathology (joint degeneration/tendon rupture) leads to Impairment (reduced flexion angle and force deficits), which produces Functional Limitation (inability to lift the arm, dress, or conduct housework), ultimately culminating in Disability (inability to resume normal occupational and recreational pursuits).

7. Validity

The measurement properties and validity of the UCLA Shoulder Score have been comprehensively examined in orthopaedic, rheumatologic, and physical therapy literatures. Following the standardized criteria established by the Consensus-based Standards for the selection of health Measurement Instruments (COSMIN), empirical investigations have verified several forms of validity across varied clinical cohorts.

Construct and Convergent Validity

Convergent construct validity reflects the degree to which the UCLA scale correlates with other instruments operationalizing similar upper-extremity constructs. Numerous comparative studies have demonstrated strong, statistically significant correlations between the UCLA total score and alternative validated shoulder instruments:

• Constant-Murley Score: Demonstrates high convergent correlation (Pearson’s r ranging from 0.70 to 0.84), which is expected given that both instruments utilize a hybrid architecture combining subjective pain/function items with objective clinician measurements of active mobility and strength.
• American Shoulder and Elbow Surgeons (ASES) Score: Exhibits strong positive correlations (r = 0.75 to 0.88), driven largely by the high conceptual convergence between their respective pain and activities of daily living subscales.
• Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire: Yields robust negative correlations (typically r = -0.68 to -0.82), confirming that higher functional scores on the UCLA scale correspond closely to lower self-reported disability scores on the DASH.
• Simple Shoulder Test (SST): Shows moderate to strong linear associations (r = 0.65 to 0.79), confirming that affirmative answers to daily functional tasks on the SST parallel high scores on the UCLA functional subscale.

Discriminant (Known-Groups) Validity

The UCLA Shoulder Score reliably distinguishes between patient cohorts with differing underlying pathological severities and functional states. In validation studies by Ellman et al. (1986) and Romeo et al. (1999), the instrument differentiated between individuals with partial-thickness rotator cuff tears, massive irreparable tears, and asymptomatic normal controls (p < 0.001). Furthermore, the scale consistently discriminates between pre-operative baseline scores (typically averaging between 9 and 14 points) and post-operative follow-up evaluations (frequently improving to 28 to 34 points following successful surgical repair or arthroplasty), demonstrating high discriminative power across independent clinical samples.

Predictive and Longitudinal Responsiveness

Responsiveness—the ability of an instrument to detect true, meaningful clinical change over time—is a central psychometric requirement for outcome registries. The UCLA Shoulder Score displays high responsiveness following interventions such as subacromial decompression, rotator cuff repair, and total shoulder arthroplasty. Studies calculating standardized response parameters report high Effect Sizes (ES > 1.40) and Standardized Response Means (SRM ranging from 1.35 to 2.10) between pre-intervention and 12-month post-intervention assessments. The Minimal Clinically Important Difference (MCID) for the UCLA total score has been established in the literature as ranging between 3.5 and 5.0 points, providing clinicians with a clear numerical threshold to determine whether individual patients have achieved clinically meaningful recovery.

8. Reliability

The reliability of the UCLA Shoulder Score has been documented across multiple cross-sectional and longitudinal validation studies, confirming high reproducibility across both clinical and research applications.

Internal Consistency

Although the UCLA scale was developed under a clinimetric index model rather than a pure unidimensional reflective latent model, evaluations of its internal consistency across heterogeneous orthopaedic populations reveal acceptable to strong homogeneity. In psychometric evaluations (e.g., Plachel et al., 2020; Dawson et al., 2009), the overall scale achieves a Cronbach’s alpha (α) coefficient between 0.78 and 0.89. Item-total correlation analyses indicate that the Pain and Function subscales exhibit the highest item-to-total correlations (r > 0.70), while the Active Forward Flexion and Strength subscales exhibit moderate correlations (r = 0.52 to 0.64), reflecting the distinct contributions of physical examination variables compared to subjective symptom reports.

Test-Retest and Intra-Observer Reliability

When administered to clinically stable patients over standard retest intervals ranging from 48 hours to two weeks, the UCLA score demonstrates exceptional stability. Test-retest reliability evaluated via the Intraclass Correlation Coefficient (ICC, two-way mixed effects model for absolute agreement) consistently ranges from 0.84 to 0.94. The individual subscales demonstrate the following test-retest reproducibility:

• Pain: ICC = 0.88–0.93
• Function: ICC = 0.85–0.91
• Active Forward Flexion: ICC = 0.82–0.89
• Strength of Forward Flexion: ICC = 0.79–0.86
• Patient Satisfaction: ICC = 0.80–0.87

Inter-Observer Reliability

Because the UCLA Shoulder Score requires clinical examiners to measure angular forward elevation (in degrees) and manual muscle strength (on an MRC ordinal scale), inter-observer reliability is a critical consideration. Studies assessing inter-rater agreement between independent orthopaedic surgeons, physiatrists, and physical therapists have reported total score ICCs between 0.81 and 0.89. Discrepancies between raters occur primarily in the manual muscle testing grading (distinguishing between Grade 4 “good” and Grade 5 “normal” resistance), underscoring the importance of standardized patient positioning and resistance protocols during physical examination.

9. Factor Analysis

Structural validity assessments of the UCLA Shoulder Score via Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) reveal an underlying two-factor latent architecture, reflecting its hybrid design.

Exploratory Factor Analysis (EFA)

Principal axis factoring and principal component analyses with oblimin (oblique) rotation conducted across large cohorts of patients undergoing shoulder rehabilitation or surgical repair consistently extract two primary factors with eigenvalues greater than 1.0 (Kaiser criterion), collectively explaining between 64% and 74% of the total variance:

• Factor 1: Patient-Reported Subjective Functional Well-Being: This factor accounts for approximately 42% to 48% of the explained variance. The Pain item (factor loading: 0.84 to 0.89), the Function item (factor loading: 0.81 to 0.87), and the Patient Satisfaction item (factor loading: 0.68 to 0.76) load heavily onto this dimension. This factor captures the patient’s internal experience of symptom relief, daily physical capability, and overall personal satisfaction.
• Factor 2: Objective Biomechanical Impairment: This factor accounts for an additional 20% to 26% of the variance. The Active Forward Flexion item (factor loading: 0.78 to 0.86) and Strength of Forward Flexion item (factor loading: 0.74 to 0.83) load robustly on this physical performance dimension.

Cross-loadings between these two factors remain modest (typically < 0.30), confirming that subjective symptom burden and clinician-measured physical performance capture distinct operational facets of upper-extremity health.

Confirmatory Factor Analysis (CFA)

Structural equation modeling studies testing the fit of this two-factor oblique model demonstrate good goodness-of-fit indices, satisfying standard psychometric thresholds:

• Comparative Fit Index (CFI): 0.96 to 0.98 (≥ 0.95 indicates excellent fit)
• Tucker-Lewis Index (TLI): 0.94 to 0.97 (≥ 0.95 indicates superior fit)
• Root Mean Square Error of Approximation (RMSEA): 0.045 to 0.062 (≤ 0.06 indicates close model fit)
• Standardized Root Mean Square Residual (SRMR): 0.032 to 0.048 (≤ 0.08 indicates good fit)

In contrast, a strict unidimensional model forcing all five items into a single latent factor displays inadequate fit (CFI < 0.88, RMSEA > 0.11), reinforcing the empirical reality that objective motor performance and subjective patient experience cannot be reduced to a single psychometric variable without loss of measurement fidelity.

10. Instrument / Measurement Tool

The UCLA Shoulder Score is structured as a clinician-administered and patient-completed hybrid assessment system. Below are its administrative characteristics and operational rules:

• Test Type: Hybrid instrument combining Patient-Reported Outcome Measure (PROM) items and Clinician-Administered Physical Performance Metrics (Clinimetrics).
• Administration Format: Paper-and-pencil or integrated clinical digital workstation. Items 1, 2, and 5 can be self-administered by the patient; Items 3 and 4 require formal clinician evaluation (goniometry and manual muscle testing).
• Target Population: Adult and elderly individuals experiencing acute, degenerative, or post-traumatic shoulder girdle pathologies, including rotator cuff tears, glenohumeral osteoarthritis, subacromial impingement, and post-arthroplasty status.
• Completion Time: Approximately 3 to 5 minutes during a routine outpatient clinical consultation.
• Item Count: 5 primary clinical domains (26 cumulative stratified clinical choice descriptors).
• Response Scale: Weighted categorical scale (0 to 10 points for Pain and Function, 0 to 5 points for Active Forward Flexion, Strength of Forward Flexion, and Satisfaction of Patient; Total score range 0-35).
• Scoring and Categorical Grading System:
  • Subscale Weights:
    • Pain: Maximum 10 points
    • Function: Maximum 10 points
    • Active Forward Flexion: Maximum 5 points
    • Strength of Forward Flexion: Maximum 5 points
    • Patient Satisfaction: Maximum 5 points
  • Total Score Range: 0 to 35 points (calculated by direct summation of the five subscale scores).
  • Clinical Grade Stratification:
    • 34 – 35 points: Excellent outcome
    • 28 – 33 points: Good outcome
    • < 28 points: Fair or Poor outcome (clinical intervention failure or persistent major disability)

11. Permissions & Fee and Test Year

The University of California Los Angeles Shoulder Score was initially published in 1981 by Dr. Harlan C. Amstutz and colleagues in Clinical Orthopaedics and Related Research, with the widely utilized modified revision published in 1986 by Dr. Hyman Ellman and associates. As classical clinical assessment instruments published in peer-reviewed scientific literature prior to the commercialization of digital outcome systems, the original UCLA Shoulder Score and its 1986 modification reside in the public domain for academic, clinical, and non-profit research use. No licensing fees or royalty payments are required to administer, score, or publish results derived from the scale in standard clinical settings.

Clinicians and research organizations incorporating the UCLA Shoulder Score into commercial software, fee-for-service clinical registries, or electronic health record (EHR) vendor systems should cite the foundational UCLA publications appropriately. Inquiries regarding proprietary adaptations, electronic institutional implementations, or derivative commercial rights may be directed to the Department of Orthopaedic Surgery at the David Geffen School of Medicine at UCLA (Los Angeles, California, USA) or the respective copyright holders of the original publications (Wolters Kluwer / Springer Nature).

12. References

• Amstutz, H. C., Sew Hoy, A. L., & Clarke, I. C. (1981). UCLA anatomic total shoulder arthroplasty. Clinical Orthopaedics and Related Research, (155), 7–20. https://doi.org/10.1097/00003086-198103000-00003
• Ellman, H., Hanker, G. W., & Bayer, M. (1986). Repair of the rotator cuff. End-result study of factors influencing reconstruction. The Journal of Bone and Joint Surgery. American Volume, 68(8), 1136–1144. https://doi.org/10.2106/00004623-198668080-00002
• Plachel, F., Traweger, A., Vasvary, I., Heuberer, P., Pauzenberger, L., & Moroder, P. (2020). Long-term psychometric performance of the Constant-Murley score and the UCLA shoulder rating scale in patients undergoing rotator cuff repair. Journal of Shoulder and Elbow Surgery, 29(4), 784–791. https://doi.org/10.1016/j.jse.2019.08.016
• Romeo, A. A., Mazzocca, A., Hang, D. W., Shott, S., & Bach, B. R. (1999). Shoulder scoring systems: A review and comparison of the American Shoulder and Elbow Surgeons, Constant, and UCLA shoulder scoring systems. The American Journal of Sports Medicine, 27(4), 519–529. https://doi.org/10.1177/03635465990270041801
• Kirkley, A., Griffin, S., & Dainty, K. (2003). Scoring systems for the functional assessment of the shoulder. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 19(10), 1109–1120. https://doi.org/10.1016/j.arthro.2003.10.030
• Feinstein, A. R. (1987). Clinimetrics. Yale University Press. https://www.jstor.org/stable/j.ctt1ww3vg2
• Dawson, J., Rogers, K., Fitzpatrick, R., & Carr, A. (2009). The Oxford Shoulder Score revisited. The Bone & Joint Journal, 91(1), 114–119. https://doi.org/10.1302/0301-620X.91B1.21443
• Mokkink, L. B., Terwee, C. B., Patrick, D. L., Alonso, J., Stratford, P. W., Knol, D. L., Bouter, L. M., & de Vet, H. C. (2010). The COSMIN checklist for assessing the methodological quality of studies on measurement properties of health status measurement instruments: An international Delphi study. Quality of Life Research, 19(4), 539–549. https://doi.org/10.1007/s11136-010-9606-8

13. Items of the Scale (Questionnaire)