Chronic back pain is a prevalent condition which has significant and direct effects on the daily life. Many individuals undergo surgical intervention in hopes of pain relief, but unfortunately some patients still experience chronic back, neck or limb pain after back surgery. This condition is known as “Failed Back Surgery Syndrome.” To address the pain, an integrated approach is often implemented, utilizing pharmacologic pain management as well as physical and behavioral therapy. When this multidisciplinary approach does not work, neuromodulation therapies are used such as spinal cord stimulation (SCS). This therapy has been used successfully on patients with neuropathic leg and back pain.
Studies on the use of SCS have been completed for effectiveness. Such studies utilized SCS on patients with varying types of evaluation. One study utilized pain scores, quality of life, functional capacity and satisfaction, another study completed a cost analysis, while a more quantitative study used gyroscopes and accelerometer placed on the trunk and lower limbs to analyze posture and gait and patients using SCS. Together these studies have indicated the potential of SCS therapy for pain relief, as well as improvement in gait, posture, physical activity function and quality of life.
In order to obtain a thorough analysis of movement, a 3D gait analysis is necessary. Often patients adjust their muscle and movement strategies in response to pain. These compensatory strategies can lead to abnormal gait and posture. A research group from Italy aimed to verify whether SCS has benefits for gait and posture by utilizing 3D gait analysis. The study focused on failed back surgery syndrome (FBSS) patients with implanted SCS devices and quantifying changes in their movement. For gait and posture analysis, patients stood still and walked with the device on and off. During the trials, instrumented movement analysis was performed with a BTS Bioengineering Gait Lab. Reflective makers were placed on anatomical landmarks based on the Davis protocol. Infrared SMART-DX cameras acquired the motion tracking data, while force plates (INFINI-T by BTS Bioengineering) acquired ground reaction force data. For trunk motion analysis, the patients were asked to perform flexion-extension, lateral bending and rotation with makers on the spine while standing on the force plates. These data along with anthropomorphic measures were input into the BTS Software for 3D reconstruction as well as kinematic and dynamic motion analysis.
In addition to the instrumented gait analysis, the patients underwent clinical evaluation before and after use of the SCS with surveys and questionnaires on physical functionality, pain, effect on daily function, and mental health. When comparing the self-assessment before and after use of the SCS devices, it was found that the perceived physical functioning, pain and health status improved in performance and negative symptoms were reduced for all of the patients.
From the motion analysis data, general improvements were also observed. For gait and posture parameters, it was found that there was improvement in velocity, step and stride length, and symmetry during the gait cycles. Analysis of the trunk movement provided insights on the change in lateral bending and range of motion. All patients demonstrated modified trunk strategies when using the SCS device with smoother execution of the task. Some increase of range of motion was observed for left to right bending with statistical significance in the coronal plane.
From these results, the authors confirmed that SCS therapy can improve gait, posture and wellbeing of patients suffering from back pain. These improvements can be shown with quantifiable results through 3D Gait analysis technology. The authors proposed that the SCS offers a window of reduced pain which can be used to optimize rehabilitation and therapy programs. The technology facilitated observation of direct effects of the therapy with objective results reflecting the reduction compensatory strategies of those who suffer from back pain. With such technology, gait and trunk control can be more deeply understood helping healthcare professionals implement improved rehabilitation and therapy.
This post was based on the following article, cited:
Brugliera, L., De Luca, A., Corna, S., Bertolotto, M., Checchia, G. A., Cioni, M., … & Lentino, C. (2017). Spinal Cord Stimulation in Failed Back Surgery Syndrome: Effects on Posture and Gait—A Preliminary 3D Biomechanical Study. Pain Research and Management, 2017.