This research study is being conducted at the Medical University of South Carolina (MUSC). The purpose of this study is to better understand injury to the small nerves that run between the ribs following rib fractures, and to learn what normal sensation and muscle appearance of the abdominal wall (muscles of the stomach area) look like in healthy adults. This information will help doctors better recognize and diagnose nerve injuries in patients who have had trauma, surgery, or other conditions affecting the abdominal wall.

Researchers will use simple sensory testing of the skin of the abdomen and ultrasound imaging to measure abdominal muscle structure. The sensory testing, called two-point discrimination, measures how well participants can tell the difference between two nearby points touching the skin using a small measuring tool that lightly touches the skin of the abdomen. Ultrasound imaging uses sound waves to create images of the inside of the body and will be used to measure the thickness and appearance of the abdominal muscles. This study includes two groups of participants: healthy volunteers and individuals with rib fractures.

Healthy volunteers will complete a single study visit lasting about 45 minutes, during which participants will undergo sensory testing, ultrasound imaging, and a short questionnaire. Participants with rib fractures will complete research procedures during their scheduled clinical follow-up visits, which include a baseline visit and three follow-up visits over approximately 12 weeks; research activities, including ultrasound imaging, will add about 30 minutes to each visit.

This is a research study to find out if Qutenza 8% capsaicin topical system is safe and effective when treating subjects with lower back pain (LBP) that is caused by damage at or near the nerve's root in the lower back leg (lumbosacral radiculopathy) which is pain that can move all the way down the back of the leg. The pain may also start outside of the spinal cord, in the peripheral nerves and may also be felt all the way down the back of the leg (neuropathic LBP). Qutenza 8% capsaicin, the study drug, is currently FDA approved to treat nerve pain after a shingles outbreak in addition to a type of nerve pain in the feet associated with diabetes. In this study a maximum of four patches per visit (sized 14cm x 20 cm) will be used to deliver the Qutenza 8% capsaicin to your skin.

If a subject meets the qualifications for this study, in addition to their standard of care for their LBP, they will be treated with Qutenza 8% capsaicin topical system and can expect to have a total of 5 visits in a 12 month period. Each visit will require subjects to fill out several surveys and receive treatment patches for their LBP (your doctor will decide if you will need to be retreated at each visit based on your symptoms). This is an open-label study and all participants will receive Qutenza 8% capsaicin topical system. The study visits are estimated to take 90 minutes upwards to 120 minutes.