The validity and reliability of DrGoniometer, a smartphone application, for measuring forearm supination

Area of Science:

• Orthopedics and Rehabilitation Science
• Biomedical Engineering
• Clinical Measurement Validation

Background:

• Forearm supination is crucial for daily activities, commonly measured with universal goniometers.
• DrGoniometer, a smartphone application, has prior validation for other joint measurements.

Purpose of the Study:

• To assess the reliability and validity of DrGoniometer for forearm supination measurement.
• To evaluate its use in healthy individuals and those with forearm fractures.

Main Methods:

• A clinical measurement study involving 30 participants with non-surgically treated distal radius fractures and 30 healthy controls.
• Forearm supination was measured using DrGoniometer and a universal goniometer by two blinded assessors.
• Reliability was determined using Intra-class Correlation Coefficients (ICCs), standard error of measurement, and minimal detectable change. Validity was assessed using Pearson's correlation coefficient.

Main Results:

• High intra-rater reliability (ICCs 0.74-0.88) was observed for both devices in both groups.
• Inter-rater reliability was high for the fractured forearm group (0.76 and 0.72) but low for the healthy forearm group (0.34 and 0.42).
• Excellent correlation (0.94 and 0.93) was found between DrGoniometer and the universal goniometer across both groups.

Conclusions:

• DrGoniometer demonstrates good-to-excellent intra-rater and inter-rater reliability for forearm supination, particularly in fractured limbs.
• While inter-rater reliability was lower in healthy forearms, potentially due to instructions, DrGoniometer is a valid and efficient alternative tool.
• The smartphone application offers advantages in speed and digital record-keeping for forearm supination assessment.