Assessment and Post-Intervention recovery following surgery for Lumbar Disc Herniation based on objective gait metrics from wearable devices using the Gait Posture index: GPi™.

Abstract Objective Surgery for Lumbar Disc Herniation (LDH) presents an option for patients whom fail conservative measures.The objective of this clinical study is to investigate a novel, objective outcome measure in patients undergoing lumbar microdiscectomy. Methods 24 patients were evaluated pre- and post-operatively using the Oswestry Disability Index (ODI), and a novel objective scoring tool, the Gait Posture index (GPi™). The score is calculated from 4 key physical health metrics: Daily Step Count, Walking Speed, Step Length and walking Posture. The GPi ranges from 0 (non-ambulant) to 100 (excellent walking performance). Wearable accelerometers and observational recording were used to evaluate the components of the GPi. The GPi was calculated and compared with the ODI, pre and post intervention. The study was designed as a proof of concept, and confirmation of validity for use of the GPi in LDH. Results At follow-up (average 66±36 days), 23 out of 24 patients had an improvement in their GPi following surgery. The average GPi of the cohort improved from 59.33±16.06 to 85.75±9.22 with p Conclusion The GPi score is a new, objective descriptor of mobility in spinal surgery which can be used to augment traditional subjective outcome scoring surveys such as the ODI. Significant changes are seen in the GPi and its constituent metrics in patients undergoing surgery for LDH.