Reliability Comparisons of Cervical Active Range of Motion Measuring Methods: Universal Goniometer versus Virtual Reality

Research Article

Phys Med Rehabil Int. 2022; 9(1): 1195.

Reliability Comparisons of Cervical Active Range of Motion Measuring Methods: Universal Goniometer versus Virtual Reality

Carley P*, Favolise M, Moses M, Heumiller S, Rocchio F and Rubin A

Doctor of Physical Therapy, American International College, USA

*Corresponding author: Carley P, American International College, Doctor of Physical Therapy Program, 1000 State St., Springfield, MA USA

Received: December 28, 2021; Accepted: January 27, 2022; Published: February 03, 2022


The purpose of this research study is to compare the reliability of measuring active cervical range of motion performed with the universal goniometer with an FDA approved XRHealth virtual reality computer program and the Oculus Rift.

Methods: The design of the study is a single-blinded randomized controlled study. A sample size of 40 adults was recruited via email, posters, and person to person recruitment. The sample was comprised of males and females, ages 20 to 72-year-old. Equipment included a large universal goniometer with 12-inch arms and a covered full circle plastic body, oculus rift with a computer, VR Health System, chair with arms and a gait belt to control for trunk movements. All four investigators underwent a training session in the measurement of cervical range of motion utilizing a universal goniometer. Each participant was measured with each tool twice.

Results: Virtual reality demonstrated a statistically significant difference from the standard goniometer methods at a 99% confidence level (p=0.01). Both tools (goniometer and virtual reality) were found to have good to excellent inter-rater reliability.

Conclusion: This study suggests a virtual reality method can be used as a reliable clinical tool in comparison with the universal goniometric cervical active range of motion measurement. Recommendations for future studies should be focused on establishing the validity of virtual reality as an assessment tool using a larger sample size with a wide age range and those who have current cervical discomfort or are experiencing functional limitations in cervical ranges of motion.

Keywords: Virtual reality; Goniometry; Cervical ranges of motions; Examination


There is an increasing array of technologies being utilized in healthcare ranging from adaptive wearable technology, to augmented reality, and even virtual reality. More importantly, there is an expanding use of technology in clinical rehabilitative applications and the pedagogy of future physical and occupational therapy professionals. Wearable technology and virtual reality (VR) are becoming more affordable, providing more objective patient information for clinical assessment while offering improved guidance of various therapeutic interventions. References comparing the application and measurement potential of virtual reality with the universal goniometer (UG), the gold standard, were extremely limited and failed to include standardized protocols [1-3]. Therefore, this research study sought to compare the reliability of measuring active cervical range of motions with the standard universal goniometer with those taken with an Oculus Rift and an approved FDA program from XRHealth.

The reliable use of the universal goniometer is important to clinicians since it assists in the comparison of effectiveness in therapeutic interventions and assesses patient progress during rehabilitative interventions.1 Active range of motion (AROM) testing is also important for impairment testing, assisting in formulating a diagnosis, and designing plans of care. The normal ranges for cervical range of motion with a universal goniometer include 40 degrees of flexion, 50 degrees of extension, 22 degrees of lateral flexion, and approximately 50 degrees of rotation [1].

Goniometric measuring poses some important clinical limitations, one of which, the goniometer does not mimic functional movements but motions in standard anatomical planes. For example, in the application of universal goniometry, a physical therapist would instruct a patient to complete the maximum attempt of movement to achieve full, pain-free range of motion in forward cervical flexion or rotation. However, in everyday life, cervical motion is an automatic and subconscious response to the external environment, moving in diagonal planes as opposed to instructions for only a set of sagittal, frontal, or axial planes for the neck [2].

Mumammad Nazim Farooq et al. conducted a double-blind study comparing the intra-rater and inter-rater reliability between two qualified physiotherapists for cervical active range of motion using a universal goniometer. The blinded physiotherapists measurements were recorded by a third physical therapist to eliminate the potential for bias. The cervical range of motion of 19 participants without an underlying cervical pathology, ranging from 20-24 years of age, were measured while in a seated position with their back straight and secured by a strap to the chair [2]. The purpose of this method was to reduce errors caused by additional trunk movement or postural compensations. There were two different sessions for measuring cervical range of motion, with one week separating the sessions. The results of the data analysis showed strong correlation values for interrater and intra-rater reliability within sessions and between sessions. These results are consistent with the findings of multiple previous studies using similar in methods with similar high to very-high values for both intra and inter-reliability [2-5]. A question remaining is, “Are there any current technologies that would have the same reliable capabilities for measuring cervical ranges of motions other than a universal goniometer”?

Virtual reality and motion detection capabilities have the potential ability to provide an assessment of dynamic cervical motion in a more interactive environment that can be comparable with real world routines. Also, virtual reality may provide the additional facet of extrinsic motivation. Motivation is defined by Mei et al. as an internal state or condition that activates guides, maintains or directs behaviors [6]. Virtual reality provides a situated learning environment that engages the participant while providing continuous and varied external feedback. This study by Mei et al. discussed the features of virtual reality that included immersion, interaction, imagination, and real-time interactivity that combined afforded participants broad range effective engagement experiences.6 The authors, using a Cronbach a Coefficient Value, determined the reliability of learning motivation using virtual reality showed a high coefficient value of 0.79 [6]. The study also found that situated learning contributed 18.9% to the participant’s level of motivation [6]. Based on previous literature, it was hypothesized that motivation can be a powerful component in achieving these high results.

The potential applications of virtual reality can include both outpatient and inpatient clinical setting that could extend to remote interventions for the community or homecare setting in coordination with current Telehealth initiatives. Only one study was found to specifically address cervical range of motion reliability and validity using virtual reality. A study by Sarig-Bahat et al. investigated thirty asymptomatic cervical participants that were assessed using both conventional goniometer and virtual reality methods. The purpose of this study was to assess both inter and intra-rater repeatability. Results showed that intra and inter-rater reliability was practical for both the virtual reality and the conventional goniometer methods. More importantly, there was better repeatability when utilizing the virtual reality method [2].

As the nation’s healthcare system expands the use of technology, virtual reality presents a more engaging patient experience and intervention for dynamic functional movement by manipulating their simulated reality transitioning to a more functional reality [6,7]. Lastly, the adaptation of new technologies as part of education, the benefits of virtual reality studies may provide a new pedagogy for teaching and better preparation of future healthcare professionals. The proposed question is, “To what degree is the reliability of Oculus Rift - XRHealth virtual reality methods compared with the standard goniometry measurements for measuring active cervical range of motion”?


The study design was a single-blinded randomized controlled study. A sample size of 40 adults was recruited via email, posters, and person to person recruitment. The age range was 20 to 72-year-old males and females. Inclusion criteria required willing participants to be free of known current cervical pathologies. Participants were excluded if they stated they had a history of cervical dysfunction, surgery, or trauma. To estimate the precision of inferences, a power calculation indicated a sample size of 30 subjects would be an adequate sample size. However, a targeted sample size of 40 was chosen to balance the interactions between each of the four raters. The goal was to have approximately 10 subjects for each paired group of raters with one being blinded to the actual goniometer and virtual reality measurements to avoid the potential for bias and to assess inter-rater reliability. Each participant was tested a total of four times, twice on the virtual reality and twice with the universal goniometer. Each rater performed one virtual reality session and one goniometer session to measure cervical motions in six directions. All participants were given written information regarding the purpose and nature of the study. An informed consent form was signed by each subject prior to participating in the study.

Measurement Procedure

The four investigators were randomly assigned numbers from one to four such that each were identified as Investigator/Rater 1, Investigator/Rater 2, Investigator/Rater 3, and Investigator/Rater 4, and then randomly divided into two rotating pairs. For both methods (universal goniometer and virtual reality), one of the investigators for each tested subject was responsible for measuring the cervical range of motion of the subject but was blinded to the actual numerical values. The second investigator recorded the values on a sheet of paper (Figure 1). Each subject entered the room with two investigators/raters to initially review the informed consent form before signing and to listen to the prepared instructions. The subject would be instructed to sit comfortably in the chair with their feet flat on the floor. A gait belt would be used around the subject’s chest to secure the back of the chair to control for any potential compensatory trunk movements. The “measuring” investigator/rater would measure cervical ranges of motions in the same sequence of motions involving flexion, extension, right and left side bending, and right and left rotation for both the blinded universal goniometer and virtual reality methods. The “measuring” investigator/rater would present the goniometer with the results of each measured motion to the “recording” investigator/rater. The “recording” investigator/rater would record all values on the form in Appendix A.