This study wants to see if a special tool helps treat long-lasting pain in the trunk or limbs. The tool is called ECAP-controlled closed-loop SCS. SCS stands for Spinal Cord Stimulation, which means sending tiny electrical signals to the spine to reduce pain. ECAP stands for Evoked Compound Action Potentials, which are signals from nerves that help adjust the SCS device. This study checks if measuring these nerve signals can guide treatment better.

• **Eligibility:** Participants must have chronic pain of the trunk or limbs, be at least 18 years old, and not be pregnant.
• **Study Duration:** Participants must be willing to have a temporary trial with the Evoke System, which helps manage pain.
• **Participation Requirements:** Participants need to understand and agree to the study rules, and be able to attend all study visits.

This study is a good opportunity to potentially find relief if you have severe pain and are planning to try the Evoke System. Remember to talk to your doctor to see if this study is right for you.