Validity of goniometric elbow measurements: comparative study with a radiographic method

Area of Science:

• Orthopedics
• Biomechanical measurement
• Radiology

Background:

• The universal goniometer is a standard tool for assessing elbow range of motion (ROM) and carrying angle.
• Concerns exist regarding the intertester reliability of goniometric measurements.

Purpose of the Study:

• To evaluate the validity of goniometric elbow ROM measurements against radiographic assessments.
• To determine the reliability of both goniometric and radiographic measurement techniques.

Main Methods:

• Elbow ROM and carrying angle were measured in 51 healthy subjects (102 elbows) using a universal goniometer and radiographs.
• Goniometric measurements were taken three times by one observer; radiographic measurements were performed by two independent examiners.
• Paired t-tests, Pearson's correlation, and the Bland and Altman method were used for analysis.

Main Results:

• Intraclass correlation coefficients (ICC) indicated high reliability for both methods (goniometric: 0.945-0.973; radiographic: 0.980-0.991).
• Both methods showed correlation for total ROM in flexion and extension.
• Maximal errors for goniometric measurements were approximately 10.3° for extension, 7.0° for flexion, and 6.5° for carrying angle.

Conclusions:

• Goniometric and radiographic methods for elbow ROM assessment show differences but are correlated.
• The universal goniometer is a practical clinical tool, with a maximal error of ~10° for elbow ROM.
• Radiographic measurements are recommended for research requiring higher precision.