Introduction
Patients with low back pain have limitations in functional capacity due impaired back function and kinesiophobia, resulting in worsened functional status, reduced ability to work and quality of life.
The Oswestry Disability Index (ODI) is the most commonly used questionnaire to assess the functional capacity of such patients (Fairbank, Spine 2000). However, it is limited by relying on patient recollection and feedback. Therefore, objective and easy to use validated methods for measuring patients function are required. We evaluated the SPINE device (Epionics Medical GmbH, Potsdam, Germany), which allows the objective assessment of the lumbar spine motion and function in chronic back patients candidate for high-frequency Spinal Cord Stimulation at 10 kHz (HF10 SCS).
Material and Methods:  
Consecutive chronic back pain patients referred to our clinic and candidate for HF10 SCS were assessed pre-SCS trial at 6 weeks 3 months and 6 months post SCS system implantation.
All patients completed an ODI questionnaire and underwent the Epionics measurements in order to measure the range/angle and velocity of motion for pre-defined move- ments, and the age- and genderspecific overall flexibility score.
Epionics SPINE
The Epionics SPINE system is a CE-marked system (Fig. 1) which allows the objective evaluation of movement dynamics and function through the recording of a pre- determined standard choreography and yields information on movement range and dynamics in about 15 minutes (Fig. 2)
Results:  
14 Failed Back Surgery Syndrome patients, including 9 who had undergone fusion, and 2 patients without prior back surgery were assessed.
At baseline, their ODI was 61 ± 4 (mean ± SEM) and 75% of the patients had a poor overall flexibility status as assessed with the SPINE system. All the patients had a successful HF10 SCS trial and were implanted with an Implantable Pulse Generator. During their follow-up, their ODI score decreased from to 37 ± 4 at 6 weeks and 29 ± 4 at 3 months (p<0.001 compared to baseline – Graph 1), with the proportion of patients with severe disability or crippled decreasing from 81% down to 18% at 3 months (Graph. 2)
The Epionics overall flexibility score improved significantly, with the proportion of patients being classified as Poor/Average/ Good improving from 75%/12.5%/12.5% to 33%/13%/53%.at 6 weeks and 0%/28%/ 72%.at 3 months (Graph. 3)
Significant improvements were observed in spinal movement velocities at 6 weeks and 3 months, and in range of motion at 3 months (Graphs 4 and 5)
Conclusion:  
The Epionics functional measurements are easy to perform in routine practice and provide objective, clinically relevant information on lumbar spine function in chronic back pain patients. In SCS patients, this device provides objective information demonstrating the significant impact of HF10 SCS in improving patients function. Further research is needed to confirm these results.

OBJECTIVE MEASUREMENTS OF LUMBAR SPINE FUNCTION IN BACK PAIN PATIENTS UNDERGOING HIGH-FREQUENCY SPINAL CORD STIMULATION AT 10 KHZ