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Independent & peer-reviewed

The evidence behind Angulus

Angulus isn't just marketed as accurate — its measurements have been used and formally evaluated in independent, peer-reviewed research across clinical specialties. Here's the record.

40+

Published studies

2021–2026

Six years of use

up to 0.99

ICC reliability

8

Clinical domains

Reliability & validity

Studies that measured Angulus itself

Several groups specifically tested Angulus's reliability and validity against reference methods — including manual goniometry and radiographic assessment. These are the headline results.

Quadriceps (Q) angleHealthy women, n=50

ICC 0.98–0.99 · r=0.99

Aafreen et al., 2024 — Int J Ther Rehabil · source ↗

Rearfoot & medial arch angleConcurrent validity, n=100

ICC 0.96–0.97 · r=0.73–0.84

Chaturvedi et al., 2026 — Rev Pesq Fisio · source ↗

Proximal femur physisRadiographs, n=378

0.79–0.92 inter-observer

Garg et al., 2025 — J Clin Orthop Trauma · source ↗

Hypospadias curvatureInter-observer, n=52

R = 0.983

Mosa et al., 2022 — J Pediatr Urol · source ↗

Head-load posture changeInter-rater, n=100

0.90 inter-rater

Kurten et al., 2022 — Occup Health SA · source ↗

Thoracolumbar spine ROMLow back pain, n=64

ICC 0.71–0.83 intra

Aburub et al., 2025 — Int J Ther Rehabil · source ↗

Elbow & wrist ROMvs. photogrammetry

Matches manual goniometry

Quintero-Diaz et al., 2025 — Phys Ther Rev · source ↗

Wrist flexion & extensionValidity study (named "Angulus")

Reliability & validity

Porkodi et al., 2023 — IEEE AISP · source ↗

How to read this: ICC (intraclass correlation) and r/R values closer to 1.0 indicate stronger agreement. Values above 0.90 are generally considered excellent reliability. Where a study reported a range across movements or raters, the full range is shown.

The full record

Studies by clinical domain

A selection of independent publications that used or evaluated Angulus, grouped by area. Each links to the original paper.

Upper limb — shoulder, elbow, wrist & hand

11 studies

Reliability of manual goniometry vs. photogrammetry for elbow and wrist range of motion

Quintero-Diaz et al., 2025 · Physical Therapy Reviews

≈ manual gonioPaper ↗

Reliability and Validity of Angulus – Smartphone Application for Measuring Wrist Flexion and Extension

Porkodi et al., 2023 · IEEE AISP

validity studyPaper ↗

The Validity and Reliability of a Smartphone Application for Measuring Wrist and Metacarpophalangeal Joint Motion

Özçelep et al., 2024 · Cureus, 16

Radial Head Resection and Lateral Collateral Ligament Repair in the Terrible Triad of the Elbow

Rouhani et al., 2023 · Trauma Monthly, 28(1)

Assessment of selected upper limb ranges of motion in violinists during instrument performance

Gol & Szczechowicz, 2024 · Health Promot Phys Act, 29(4)

Arthrodilation: A Conservative Management Option for Adhesive Capsulitis (frozen shoulder)

Flores-Villalobos & Cruz-López, 2023 · Acta Ortop Mex, 37

Rehabilitation technology in arm and hand function in myotonic dystrophy type 1

Fossmo et al., 2024 · J Neuromuscul Dis

3D Printed vs. Traditional Finger Orthoses: A Force Comparison

Humbert et al., 2025 · Indian J Orthop

Optimal Design of a Bilateral Robotic Motion-Assisted Finger Exoskeleton for Home Rehabilitation

Valayil & Tanev, 2024 · Machines, 12:685

Smartphone-Based Hand Function Assessment: Systematic Review

Fu et al., 2024 · J Med Internet Res, 26

reviewPaper ↗

Fixed vs. Variable Angle Volar Locking Plates in Intra-articular Distal Radius Fractures

Garg et al., 2025 · Malaysian Orthop J, 19(2)

Knee & lower limb

5 studies

Reliability and validity of a smartphone goniometer app for measuring the quadriceps angle in healthy women

Aafreen et al., 2024 · Int J Ther Rehabil, 31(2)

ICC 0.98–0.99n=50Paper ↗

PNF and Functional Stabilization Exercise in Patellofemoral Pain Syndrome using a smartphone goniometer app

Thangavelu et al., 2026 · ICDSMLA 2024

Posterior Tibial Slope and Metaphysio-Diaphyseal Angle in Radiographic Severity of Knee Osteoarthritis

Jain et al., 2025 · J Orthop Case Rep, 15(10)

Clinical Improvement With Total Knee Arthroplasty in Valgus Knee Deformities: A Case Series

Kv et al., 2024 · Cureus, 16

Swiss Ball vs. McKenzie Exercise among Football Players with Anterior Pelvic Tilt

Mahenthiran & Ramalingam, 2024 · Indian J Physiother Occup Ther, 18

n=30

Foot & ankle

3 studies

Concurrent validity and reliability of the Angulus app for rearfoot angle and medial longitudinal arch angle

Chaturvedi et al., 2026 · Rev Pesq Fisio, 16

ICC 0.96–0.97n=100Paper ↗

Degree of Hallux Valgus and Pain Level among Vocational School Teachers

Septiani et al., 2025 · Medical Journal of Nusantara, 4(1)

Screw Hemiepiphysiodesis for Acquired Ankle Valgus in Children

Jain et al., 2021 · Int J Paediatr Orthop, 7(3)

n=18 anklesPaper ↗

Spine, neck & posture

4 studies

Smartphone goniometer for active thoracolumbar spine ROM in non-specific low back pain: reliability and validity

Aburub et al., 2025 · Int J Ther Rehabil, 32(5)

ICC 0.71–0.83n=64Paper ↗

Reliability of smartphone goniometry in measuring postural changes in youths carrying head loads

Kurten et al., 2022 · Occup Health Southern Africa, 28(6)

0.90 inter-ratern=100Paper ↗

Kendall vs. McKenzie Exercise in Forward Shoulder Posture among College Students

Paranthaman et al., 2025 · MLTJ, 15(4)

Neck Motion Restriction: Soft Collars vs. Rigid Collars

Septiani et al., 2026 · Gaster J Health Sci, 24(1)

Hip & pediatric orthopedics

3 studies

Intra- and Interobserver Reliability of Proximal Femur Physis Parameters on Radiographs

Garg et al., 2025 · J Clin Orthop Trauma, 68

0.79–0.92n=378Paper ↗

Influence of Extra-articular Changes on Hip Function in Young Adults with a History of Perthes Disease

Brevik et al., 2026 · J Children's Orthop

Surgical Course of Lateral Femoral Cutaneous Nerve during Anterior Exposure of Paediatric Hips

Gupta et al., 2024 · J Pediatr Orthop B, 33(1)

Pediatric surgery & urology

2 studies

How accurate is eyeball measurement of curvature? A tool for hypospadias surgery

Mosa et al., 2022 · J Pediatr Urol, 18

R=0.983n=52Paper ↗

Unaided visual assessment of ventral curvature is inferior to objective app goniometry

Babu et al., 2023 · Pediatr Surg Int, 39

Occupational ergonomics & work posture

7 studies

Ergonomic Evaluation of Heavy Workload in Coffee Roasting (RULA & REBA)

Koeswara & Rahmah, 2025 · Agroindustrial Technology J, 9(1)

Optimal operative table height for anesthesiologist comfort and spinal needle insertion

Awad & Al-Hasani, 2025 · Int J Anesthesiol Sci, 7(1)

Work Posture and Musculoskeletal Disorders among Photocopying Workers

Hikmah & Asyfiradayati, 2026 · Int J Sci Environ, 6(1)

Analysis of MSDs Complaints in Forklift Operators at PT Traktor Nusantara

Ardityawan & Purwaningsih, 2025 · Industrial Eng Online J, 14(2)

Work Posture Risk Assessment (RULA) in Manual Handling Workers

Herdiana & Nugraha, 2023 · Jurnal Serambi Engineering, 8

Proposed Ergonomic Rice-Planting Tool for Farmer Group Empowerment

Rahdiana, 2023 · Buana Ilmu, 8

Ergonomic Risk and Musculoskeletal Disorders in Rice Farmers

Rahdiana et al., 2022 · Spektrum Industri, 20

Rehabilitation & telehealth

1 study

Teleassessment Methods in Orthopedic Rehabilitation (book chapter)

Elibol & Bakırhan, 2024 · Telerehabilitation, Springer Nature

Beyond the clinic — research breadth

4 studies

Epigenetic and physiological alterations in zebrafish subjected to hypergravity

Salazar et al., 2024 · PLOS ONE, 19(5)

Surfactant effects on hydrophobic broccoli leaf surfaces (contact-angle measurement)

Song et al., 2021 · Processes, 9:679

Experimental Use of Mobile Apps in Physics Education

Buongiorno & Michelini, 2021 · Atti Accad Peloritana, 99

User Requirements for a Digital Musical Instrument for the Malay Bonang

Saffian et al., 2022 · Malaysian Journal of Music, 11

About this list. These are independent, third-party publications that used or evaluated Angulus; their authors are not affiliated with Angulus and inclusion here does not imply endorsement. Findings and conclusions belong to the respective authors. This is a curated selection — for the complete, continually updated bibliography see the full research index ↗. Spotted a study we've missed? Let us know.

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