PURPOSE: To evaluate the clinical efficacy of ultrasound-guided local anesthetic injection combined with myofascial trigger point mini-needle knife therapy for acute lumbar sprain management. METHODS: In this prospective study, 60 patients (January-July 2024) received ultrasound-guided injections at the third lumbar (L3) transverse process attachment and posterior medial spinal nerve branch, combined with miniscalpel-needle release of MTrPs. Visual analog scale (VAS), modified Oswestry disability index (MODI), and lumbar range of motion (ROM) were assessed pre-treatment and on days 3 and 7 post-treatment. RESULTS: VAS scores, modified ODI scores, and ROM scores on days 3 and 7 post-treatment were significantly reduced compared to baseline (all P <
0.001). Further pairwise comparisons revealed statistically significant improvements in VAS scores (MD - 1.25
98.33% CI - 1.50 to - 0.75
P <
0.001) and modified ODI scores (MD - 2.50
98.33% CI - 3.00 to - 2.00
P <
0.001) from day 3 to day 5. However, no significant change in ROM scores was observed between days 3 and 7, indicating rapid stabilization of mobility metrics. CONCLUSIONS: The integration of ultrasound-guided anesthesia and miniscalpel-needle therapy provides rapid pain relief, functional recovery, and mobility restoration in acute lumbar sprain. This multimodal approach demonstrates clinical efficacy with minimized invasiveness, aligning with evidence supporting ultrasound-guided precision and MTrP-targeted interventions.