If we target the lumbar muiltifidi, where do our needles ACTUALLY end up?
I regularly refer to the Hannah et al. 2016 study on where the needle tip @ L4 or L5 ends based on the location and angle of insertion from the vertebrae, which shows if you place you needle just lateral to the spinous process and enter posterior-anterior @ L4, you are MOST LIKELY going to end at the lamina @ L4. If you enter about 1.2-2 finger-breadths lateral to the spinous process and angle 45 degrees medially, you will MOST LIKELY end at the L5 lamina.
This 2022 study used ultrasound imaging on individuals with high BMI’s, which can be more difficult to actually determine where the needle tips end up due to increased adiposity. This study used 100mm needles., which are quite long compared to what we typically teach in AOPT Seminars CDNMT courses. The study concluded with the probability of reaching the deep LM muscle was high (85–95%) at L4 and L5. Although the needle reached a bony landmark 85–100% of the time, it only reached the vertebra lamina as intended 70–75% of the time.
One thing to consider is the the intra-tester reliability of needle placements based on analysis of real-time and recorded US images was poor-to-moderate. But take this with the previous Hannah et al. study and we have some progressive evidence of safety and location determination for the deep LM musculature. Like the Hannah study, just because the needle ended at a boney backdrop, it may not be the level you are needling at, however reaching boney backdrop has a high correlation with reaching the intended deep LM musculature.
AOPT Seminars stays up-to-date on the best available evidence in order to provide sound instruction for the utmost in safety and precision in our courses. Thanks for reading!