Validity and reliability of a smartphone inclinometer app for measuring passive upper limb range of motion in a stroke population*

Abstract

Purpose: To demonstrate the validity and reliability of a smartphone app to measure ROM after stroke.

Materials and methods: Twenty-one stroke survivors with a diagnosis of stroke that affected the motor cortex or subcortical motor pathways and were hospital inpatients at one of two metropolitan hospitals were recruited. A within-session test-retest design was used to compare ROM measurements taken using the GetMyROM app for iPhone to those taken by a digital inclinometer. Torque-controlled passive elbow and wrist extension were collected and statistical analysis of concurrent validity and test-retest reliability performed.

Results: GetMyROM app was valid when compared to the digital inclinometer for measuring passive ROM of the elbow (r = .98, p = .0001, ICC  =  0.97) and wrist (r = .97, p = .0001, ICC  =  0.96) in individuals with acute stroke. Both the GetMyROM app and inclinometer demonstrated excellent test-retest reliability: ICC values are 0.84 to 0.93, and standard error of measurement between 6° to 10°.

Conclusion: The GetMyROM app may be implemented in a clinical setting similar to that where the study was conducted, enabling rehabilitation physicians and therapists to use a smartphone to take precise measurements of ROM in daily clinical practice.

Implications for rehabilitation

• Approximately half of all stroke survivors experience reduced passive upper limb range of movement.

• Accurate measurement of passive upper limb range of movement using validated assessments and/or instruments is paramount.

• This study demonstrates that the GetMyROM app is valid and reliable compared to the gold standard comparison (digital inclinometer), and is therefore appropriate to use in clinical settings to take precise measurements.

Keywords:

• Technology
• stroke
• upper limb
• range of movement
• validity
• reliability

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

Data is available on request from the corresponding author.

Additional information

Funding

KH is supported by a National Health and Medical Research Council (NHMRC) Early Career Fellowship (GNT1088449)