INFLUENCE OF NEURAL TENSION IN MECHANICAL NOCICEPTIVE THRESHOLDS (MNTS) OF LUMBOPELVIC REGION MUSCLES

Abstract

Neurodynamic tests are daily regarded as important in orthopedic physical assesment. Changes in neural tension provoked by these tests over differents nerve trunks in lumbopelvic region may alter the nociceptive responses of nearby tissues.

The aim of our study was to evidence changes in mechanical nociceptive thresholds (MNTs) of lumbopelvic muscles in different neurodynamic positions.

Cross-sectional study. Fifty asymptomatic volunteers were evaluated with algometer in three neurodynamic positions:

1. Contralateral side-lying position with knees at 90° of flexion, hips at 70° of flexion and spine in neutral;

2. initial position with the homolateral knee in complete extension to add neural tension of sciatic nerve;

3. initial position incorporating maximum craniocervical flexion to add neural tension within vertebral canal.

The pressure algometry was tested at one anatomical site on gluteal region 2.5 cm. below iliac crest bone and behind iliotibial band.

One physiotherapist (PT) measured MNTs unilaterally over gluteus medius. Three consecutive measurements was evaluated in the three described positions, while a second PT reported the data in kilograms (kg). A third PT was responsible for modifying the knee and craniocervical range of motion.

The findings revealed significant mean differences (SMD) (0.522 kg; 95% IC: 0.385–0.659 kg) in algometry measurements (P < 0.0001) betweeen position 1 (mean 3.632 kg; SD 1.235 kg) and position 2 (mean 3.110 kg; SD 1.233 kg), SMD (0.590 kg; 95% IC: 0.412–0.768 kg) (P < 0.0001) betweeen position 1 and position 3 (mean 3.042 kg; SD 1.136 kg). Furthermore, no SMD between the two different neural tension positions (P < 0.420).

We concluded that MNTs of lumbopelvic muscles decrease with neural tension positions. MNTs decrease is similar with sciatic nerve and vertebral canal neural tension positions. So, neurodynamic positions are important procedures to be taken into account in clinical reasoning, both physical therapy diagnosis and treatment.