The effect of spinal position on sciatic nerve excursion during seated neural mobilisation exercises: an in vivo study using ultrasound imaging.

The study used 34 healthy adults, so it cannot show what happens in people with sciatic nerve problems or leg pain. The outcome was nerve movement measured by ultrasound, not pain, function, or clinical improvement. Knee range of motion was limited to a 4 out of 10 stretch sensation in slump-sitting and then kept the same in upright-sitting, which may have prevented the nerve from moving through its full range. Neck movement was active, while knee movement was passive, so the neck position was less tightly controlled. The 45 cm ball used to hold slump posture may have produced different amounts of spinal flexion in different body sizes. Foot and ankle position was not standardised, which may have affected nerve movement. The model explained 22% of the variation. More than 75% of variability was not accounted for.

The work was funded by Faculty of Health and Environmental Sciences (AUT University) Summer Student Assistant Grants. The authors declared no conflicts of interest.

Do not read the slightly larger upright-sitting values as proof that upright posture moves the sciatic nerve more. The difference was not significant, and the study measured healthy adults, not people with sciatic nerve problems or leg pain.