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

摘要

Objectives: Research has established that the amount of inherent tension a peripheral nerve tract isexposed to influences nerve excursion and joint range of movement (ROM). The effect that spinal posturehas on sciatic nerve excursion during neural mobilisation exercises has yet to be determined. The purposeof this research was to examine the influence of different sitting positions (slump-sitting versus upright-sitting) on the amount of longitudinal sciatic nerve movement during different neural mobilisation exercisescommonly used in clinical practice.Methods: High-resolution ultrasound imaging followed by frame-by-frame cross-correlation analysis wasused to assess sciatic nerve excursion. Thirty-four healthy participants each performed three differentneural mobilisation exercises in slump-sitting and upright-sitting. Means comparisons were used toexamine the influence of sitting position on sciatic nerve excursion for the three mobilisation exercises.Linear regression analysis was used to determine whether any of the demographic data representedpredictive variables for longitudinal sciatic nerve excursion.Results: There was no significant difference in sciatic nerve excursion (across all neural mobilisationexercises) observed between upright-sitting and slump-sitting positions (P50.26). Although greaterbody mass index, greater knee ROM and younger age were associated with higher levels of sciaticnerve excursion, this model of variables offered weak predictability (R 250.22).Discussion: Following this study, there is no evidence that, in healthy people, longitudinal sciatic nerveexcursion differs significantly with regards to the spinal posture (slump-sitting and upright-sitting). Furthermore, although some demographic variables are weak predictors, the high variance suggests that thereare other unknown variables that may predict sciatic nerve excursion. It can be inferred from this researchthat clinicians can individualise the design of seated neural mobilisation exercises, using different seatedpositions, based upon patient comfort and minimisation of neural mechanosensitivity with the knowledgethat sciatic nerve excursion will not be significantly influenced.