The 'Cross-Legged Foetal Sitting Neuraxial Position': Is it Beneficial?-A Prospective Randomised Clinical Trial Via Ultrasonography

Objective: The primary aim of the present study was to compare the 'cross-legged foetal sitting position' (CFSP) with the 'sitting foetal position' (SFP) sonographically. The secondary aim was to compare their comfort. Methods: A randomised, consecutive controlled, single-blinded trial was performed in Yeditepe University. A total of 50 healthy volunteers were included in the study. Exclusion criteria were body mass index (BMI) >40 kg m-2, lumbar hernia, scoliosis, history of spine surgery, lower back pain or trauma, especially pelvic or knee problems related to arthropathy and not able to do one/both of the two position techniques. The two positioning techniques were evaluated by ultrasonography (USG) and 5-point Numerical Rating Scale (5-NRS) patient satisfaction of comfort questionnaire. Seven outcomes via USG were evaluated, subcutaneous tissue (ST), skin to spinous process (S-SP), transverse diameters of right and left paraspinal muscles (RPM and LPM), interspinous gap opening (ISGO), mean of bilateral paraspinal muscle (MPM) and CFSP-SFP change (CFSP-SFP). Stretcher comfort, position comfort, lumbar comfort (LC) and abdominal comfort (AC) were evaluated by participants with the 5-NRS. Results: In the CFSP, the mean ST and S-SP were significantly (p<0.0001) shorter, and LPM, RPM and MPM were significantly (p<0.0001) wider. The mean ISGO in the CFSP was significantly (p<0.0001) broader. The CFSP was significantly more comfortable than the SFP according to the LC (p=0.02). Only ISGO was found to be significantly broader in the male participant group (p=0.01) and in the BMI=25 group (p=0.02) according to CFSP-SFP. Conclusion: Considering all ultrasonographic anatomical measurements and according to the 5-NRS related to LC, the CFSP appears to be more advantageous than the SFP as a neuraxial positioning technique.