Purpose This study investigated the immediate effects of a combined therapy, consisting of manual therapy following Functional Intramuscular Stimulation (FIMS), on pain and gait in patients with Lumbar Spinal Stenosis (LSS). Using the Zebris FDMT system, we quantitatively analyzed pre and post intervention changes in key gait parameters such as velocity, step length, and symmetry to determine statistically significant improvements Method This retrospective study analyzed the medical records of 15 LSS patients with chronic pain lasting over six weeks who could walk independently. Using a singlegroup prepost design, we measured pain with the Visual Analogue Scale (VAS) and gait parameters before and after one session of FIMS followed by 30 minutes of manual therapy. A paired t test was used for analysis. Result A single session resulted in a statistically significant reduction in pain (VAS mean: 7.67 to 5.40, p<.05). Qualitative gait parameters also improved significantly: step length increased (24.87 cm to 27.30 cm, p<.05), and the double stance ratio decreased (40.69% to 38.74%, p<.05), indicating better stability. While gait velocity showed a tendency to increase, the change was not statistically significant. Conclusion The combined therapy is an effective nonsurgical method for immediate pain relief and qualitative gait improvement in LSS patients. Although a single intervention may be insufficient to significantly increase gait velocity, its immediate positive effects on pain and gait quality demonstrate its clinical utility.