This pilot randomized controlled clinical trial aims to evaluate the effectiveness and safety of ultrasound-guided deep pharmacopuncture therapy for acute low back pain (LBP) that occurs within seven days following a traffic accident. While traditional Korean medicine-including acupuncture, herbal medicine, pharmacopuncture, and Chuna manual therapy-is commonly used for post-accident injuries, few studies have focused on deep pharmacopuncture administered under ultrasound guidance. This study will provide preliminary evidence to assess whether ultrasound-guided techniques offer added clinical benefits.

A total of 40 patients hospitalized at Jaseng Hospital of Korean Medicine in Haeundae, Korea, will be recruited and randomly assigned into two groups: the intervention group will receive integrative Korean medicine therapy plus ultrasound-guided pharmacopuncture, while the control group will receive integrative Korean medicine therapy alone. Both groups will undergo treatment during hospitalization, with the pharmacopuncture administered up to three times between hospital day 2 and day 4 in the intervention group. Baseline assessment will be done on day 2 before treatment, and the primary outcome will be measured on day 5. Follow-up assessments will be conducted at 2 and 4 weeks via telephone.

The primary outcome is the change in low back pain intensity as measured by the Numeric Rating Scale (NRS). Secondary outcomes include radiating pain, lumbar range of motion, Oswestry Disability Index (ODI), EQ-5D for quality of life, and the Patient Global Impression of Change (PGIC). Adverse events will also be monitored and classified according to established safety criteria.

This study will utilize both intention-to-treat (ITT) and per-protocol (PP) analyses, with linear mixed models and multiple imputation used to address missing data. Given the limited existing evidence on ultrasound-guided deep pharmacopuncture, this trial is designed to explore its feasibility and provide the groundwork for future large-scale trials.

Participants will be selected based on strict inclusion and exclusion criteria to ensure safety and consistency. Ethical standards including informed consent, data privacy, and ongoing safety monitoring will be rigorously upheld throughout the study.

This pragmatic, randomized, controlled pilot study investigates the comparative clinical effectiveness and safety of ultrasound-guided deep pharmacopuncture versus conventional integrative Korean medicine treatment for acute low back pain (LBP) occurring within 7 days after a traffic accident.

The study will enroll 40 hospitalized patients aged 19-70 who report moderate to severe acute LBP (NRS ≥5) and have disc narrowing visible on lumbar X-rays. Participants will be randomly assigned to one of two treatment arms (n=20 per group) using a block randomization procedure. The trial will proceed through a screening/enrollment phase, active inpatient treatment, and follow-up evaluations at 2 and 4 weeks post-enrollment.

The intervention group will receive a combination of standard integrative Korean medicine treatment and 1 to 3 sessions of ultrasound-guided deep pharmacopuncture between hospital day 2 and 4. The control group will receive standard care only, which includes acupuncture, non-ultrasound-guided pharmacopuncture, herbal medicine, and Chuna manual therapy.

The primary outcome is change in low back pain intensity (NRS) from baseline (Day 2 pre-treatment) to Day 5. Secondary outcomes include radiating pain, lumbar range of motion (ROM), functional status (Oswestry Disability Index), quality of life (EQ-5D-5L), and overall improvement (Patient Global Impression of Change). Adverse events will be systematically monitored and assessed.

The trial is designed to evaluate the feasibility, effect size estimation, and safety profile of ultrasound-guided pharmacopuncture in preparation for a larger-scale confirmatory trial. Analyses will follow both ITT and PP principles, with linear mixed models and imputation techniques for handling missing data.

The study adheres to ethical guidelines, including informed consent, privacy protection, and safety monitoring. Monitoring will be conducted by third parties per KCGP standards to ensure data quality and patient protection.

Inclusion Criteria:

Participants must meet all of the following:

Adults aged 19 to 70 years.

Patients who developed acute low back pain within 7 days after a traffic accident.

Numeric Rating Scale (NRS) score of 5 or higher for low back pain.

Radiological evidence of disc narrowing on lumbar spine X-ray.

Complaints of radiating leg pain.

Hospitalized for treatment related to the traffic accident.

Able and willing to provide written informed consent voluntarily.

Exclusion Criteria:

Participants will be excluded if they meet any of the following:

Diagnosed with serious underlying conditions causing back pain (e.g., malignancy, spinal infection, inflammatory spondylitis).

Presence of progressive or severe neurological deficits.

Underwent lumbar surgery or procedures within the past 3 weeks.

Back pain caused by non-spinal soft tissue disorders (e.g., fibromyalgia, rheumatoid arthritis, gout).

Presence of chronic conditions that could interfere with study results (e.g., cardiovascular disease, renal disease, diabetic neuropathy, dementia, epilepsy).

Taking medications that could affect study outcomes (e.g., steroids, immunosuppressants, psychiatric drugs).

Contraindicated or unsafe for acupuncture (e.g., bleeding disorders, anticoagulant therapy, severe diabetes with infection risk, severe cardiovascular conditions).

Currently pregnant or planning pregnancy.

Diagnosed with severe mental illness.

Participation in other clinical trials (excluding observational studies).

Unable to properly complete the informed consent form.

Deemed inappropriate for participation by the investigator for any other reason.