The concurrent validity and reliability of virtual reality to measure shoulder flexion and scaption range of motion

Abstract

Background

Shoulder pain commonly has a detrimental impact on patient's work and social activities. Although pain is the most common reason for seeking care, a reduction in shoulder range of motion (ROM) is another common impairment. ROM assessment is used as an evaluation tool and multiple methods are available to measure shoulder ROM. Virtual reality (VR) has been introduced into shoulder rehabilitation, mostly when exercise and ROM measurement is indicated. This study evaluated the concurrent validity and system reliability of active ROM measurements of VR for people with and without shoulder pain.

Methods

Forty volunteers participated in this study. Virtual goniometry was used to assess active shoulder ROM. Participants performed flexion and scaption to six predetermined angles. Measurements from the VR goniometer and smartphone inclinometers were recorded simultaneously. To assess reliability, two identical test sequences were performed.

Results

The concurrent validity ICCs were 0.93 for shoulder flexion and 0.94 for shoulder scaption. The VR goniometer application on average systematically overestimated the ROM compared to the smartphone inclinometer. The mean difference between goniometer values was −11.3 degrees for flexion and −10.9 for scaption. The system reliability was excellent with an overall ICC of 0.99 for the flexion movements and 0.99 for the scaption movements.

Conclusion

Although the VR system demonstrated excellent reliability, and high ICC’s for concurrent validity, the large range between the lower and upper 95% CI limits suggests it lacks measurement precision. This suggests VR, as used in this study, should not be used interchangeably with other measurement tools.

Contribution of the paper

  • Virtual reality is a relatively new technology that is being increasingly adopted in clinical practice including the assessment and treatment of people with shoulder pain.
  • Virtual reality can support the growing demand for improved efficacy and efficiency of healthcare delivery by enabling physiotherapy assessment and treatment of patients via tele-health services.
  • The VR system (hardwear and software) tested in this study demonstrated excellent reliability and excellent concurrent validity, however, the wide limits of agreement associated with the VR system suggest that the current VR system should not be used interchangeably with digital inclinometry.