Epionics SPINE Device Successfully Assesses Spinal Mobility in Patients With Axial Spondyloarthritis

The Epionics SPINE is an innovative tool to assess the spinal mobility of patients with axial spondyloarthritis.

The Epionics SPINE (ES) can effectively evaluate spinal mobility in patients with axial spondyloarthritis (axSpA), based on the Outcome Measures in Rheumatology (OMERACT) criteria, according to a study published in Journal of Rheumatology.1 Additionally, investigators discovered that range of kinetics (RoK) and range of motion (RoM) scores can supply further information regarding physical function for this patient population.

Make sure you never miss an article by signing up for our Rheumatology Network eNewsletter!

“The Epionics SPINE is an innovative tool to assess the spinal mobility of patients with axSpA. It shows promise to improve the objective quantification of spinal mobility in clinical studies and daily practice,” investigators stated. “The novel information on range of motion and the kinematic of the back movement with new the aspects speed and rotation are precisely measured.”

In this national, cross-sectional, multicenter trial, 153 patients (39 females and 114 males) were analyzed, with a total of 124 axSpA patients, 94 radiographic (r)-axSpA patients and 40 non-(nr-) axSpA patients, and 19 healthy controls (HC). Eligible patients were aged ³ 18 years. The HC group was included to compare spinal movements related to age.

Patients were examined according to the Bath AS Metrology Index (BASMI). Patient reported outcomes were determined using the Bath AS Disease Activity Index (BASDAI), Bath AS Global (BAS-G), ASAS health index (ASAS-HI), Bath AS Functional Index (BASFI), AS Disease Activity Score (ASDAS) and SF-12 (Short-Form-Health Survey), including the physical (PCS) and the mental component summary (MCS). Since the questionnaires were developed for axSpA patients, the HC cohort did not contribute to this section. Correlation analysis was specific to axSpA participants.

Demographics, such as age and gender, as well as height, weight, and distance between C7 and S1 (C7-SIPS) were reported. R-axSpA patients tended to be older (47.6±11.7) than both nr-axSpA patients (38.9±11.9) and HC patients (36.7±11.9).

Exercises were used to access participants’ spinal mobility, with patients performing the “choreography” 3 times in a row as fast as possible. Time between exercises were defined as interval time. ES determined flexion, extension, lateral flexion, rotation, and utilized the pile test, which combines different movements as a performance analysis.

Since the primary endpoint was to show that ES measurements can differentiate between health and disease, spinal mobility and questionnaire results in the axSpA cohorts were compared to those in the HC group. Examination of patients in the HC group focused on individual ES analysis.

There were significant differences between axSpA patients and the HC cohort (all p<0.001) as well as further differentiation between the r- and nr-axSpA subgroups. BASDAI, ASDAS, BAS-G, and ASAS-HI scores were comparable in patients with both r- and nr-axSpA, however, BASFI, BASMI, PCS scores were worse in the r-axSpA group when compared with the nr-axSpA group. MCS were equal in both subgroups.

BASMI and ES scores were negatively correlated (-0.76 ≤ r ≤ -0.52), with lateral lumbar flexion, lumbar flexion, cervical rotation, and tragus-to-wall distance, thus exemplifying the strongest connection between RoM and RoK. RoM results were significantly different between the r-axSpA group and the nr-axSpA group. Participants in the r-axSpA group showed a more limited and slower spinal mobility than their rn-asXpA counterparts. Unadjusted ES results between the axSpA cohorts and HC group also showed significant differences, with emphasis on RoK flexion and extension, regardless of age.

Records missing >10% variables were excluded from analysis. As there were restrictions to inclusion of only complete cases, results may be misleading. Investigators did not compare rn-axSpA with the healthy control group, due to the small number of patients, however, they do not expect there would be major differences. Lastly, there was no assessment of the presence and extent of structural changes in the spine of patients with axSpA.

“Further studies to demonstrate the sensitivity to change of therapies are ongoing, and there will be more coming in the future,” investigators concluded. “Once validated in the field of axSpA, the ES may also be helpful in daily routine, as individual limitations in spinal mobility are directly visualized, thus enabling possible therapy approaches and may help to better understand and assess limitations in functional mobility and exact impairments of patients with axSpA.”


Kiefer D, Baraliakos X, Adolf D, et al. Successful evaluation of spinal mobility measurements with the Epionics SPINE device in patients with axial spondyloarthritis compared to controls [published online ahead of print, 2021 Aug 15]. J Rheumatol. 2021;jrheum.201470. doi:10.3899/jrheum.201470