Study of QL Analgesic Response and Extent

A total of 14-18 healthy volunteers will be included. There will be three different procedure days, separated by at least one week. On each visit, the subjects will receive a QL block, according to the randomization process. Each volunteer will undergo pre-procedure screening on the first visit. The blocks will be performed on the same side, by the same anesthesiologist, with at least one week between each block. An anterior QL block will be administered on one day, a posterior QL block on another, and a lateral QL block on the third. The order will be randomized, and both the subject and the research team member assessing the block will be blinded. To compare the dermatomal sensory block distribution, the investigators will use detailed mapping with pinprick, cold, and heat stimuli. A handheld dynamometric assessment of lower extremity strength. The testing will be performed 60 to 90 minutes after performance of the blocks.

Inclusion Criteria: * Ability to provide written informed consent * Ability and willingness to comply with the study procedures and duration requirements * ASA physical status 1 or 2 * Age ≥ 18 years * Weight \> 70kg Exclusion Criteria: * BMI \> 35kg.m2 * Use of analgesics within 24 hours before the procedure * History of thoracic trauma or surgery * Abdominal deformities or abnormalities that may prevent proper block performance * Abdominal tattoos in the area of block performance * Systemic neuromuscular disease * Contraindications to regional anesthesia (e.g., infection, allergy, challenging sonoanatomy) * Structures are unable to be visualized by ultrasound * Pregnancy * Other known health conditions that would affect the participant's ability to successfully complete the study