Effects of dynamic neuromuscular stabilization training on the core muscle contractility and standing postural control in patients with chronic low back pain: a randomized controlled trial

Abstract

Background: Patients with chronic low back pain (CLBP) usually demonstrate poor postural control due to impaired core muscle function. Dynamic neuromuscular stabilization (DNS) is based on developmental kinesiology principles, utilizing infant motor patterns to treat motor disorders. DNS has been shown to improve postural control in cerebral palsy patients by activating core muscle. However, whether the DNS approach is superior for enhancing core muscle contractility and postural control in CLBP patients still remains unclear.

Objectives: This study aimed to compare the effects of DNS training and conventional core exercises on core muscle contractility and standing postural control in CLBP patients.

Methods: Sixty CLBP patients were randomly assigned to a DNS group or a control group. Participants in the DNS group received DNS training, while those in the control group completed conventional core exercises. Both groups completed 12 sessions over 4 weeks (3 sessions/week, 50 min/session). Pre- and post-intervention evaluations included diagnostic musculoskeletal ultrasound to assess the change rate of core muscles (transversus abdominis (TrA), lumbar multifidus, and diaphragm), a balance assessment system to evaluate postural control performance (center of pressure displacement (COP)), and clinical questionnaires (Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Roland-Morris Disability Questionnaire (RDQ)) for pain intensity and disability.

Results: After 4 weeks, comparisons between both groups revealed significant statistical differences in the interaction effects of time*group. These differences were observed in the change rates of the left and right TrA (F_1,58=4.820 and 3.964, p = 0.032 and 0.041), diaphragm change rate (F_1,58=11.945, p = 0.001), as well as COP velocity (F_1,58=5.283, p = 0.025), variability (F_1,58=13.189, p = 0.001) in the anterior-posterior (AP) direction, COP path length (F_1,58=6.395, p = 0.014), and COP area (F_1,58=5.038, p = 0.029) in the eye-closed condition. DNS participants showed significantly greater muscle change rates and reduced COP (p < 0.05). The scores of VAS (F_1,58=173.929, p = 0.001), ODI (F_1,58=60.871, p = 0.001), and RDQ (F_1,58=60.015, p = 0.001) decreased significantly over time, although no group differences were found between both groups (p > 0.05).

Conclusions: DNS is superior to conventional core exercises in enhancing core muscle contractility and standing postural control in CLBP patients, showing potential to reduce pain and improve disability. Its mechanism may involve the enhancement of proprioceptive feedback, particularly when visual feedback is blocked.

Trial registration: This study was registered in the Chinese Clinical Trial Registry (ChiCTR) with the registration number ChiCTR2300074595 on 10 August 2023.

Keywords: Chronic low back pain; Core muscle; Disability; Dynamic neuromuscular stabilization; Pain intensity; Postural control.

Fig. 1

CONSORT flow diagram for this study

Fig. 2

Diagram of the dynamic neuromuscular stabilization (DNS) training. (A): supine diaphragmatic breathing; (B): the dead-bug exercise; (C): side-lying rolling; (D): the bear-crawl exercise; (E): high side plank; (F): the kneeling-sitting transfer

Fig. 3

Diagram of the general exercise training for chronic low back pain (CLBP). (A): single leg-bridge; (B): double leg-bridge; (C): side bridge; (D): crunch; (E): prone plank; (F): the bird-dog exercise

Fig. 4

An example of ultrasound images of core muscles at the rest and the maximum voluntary isometric contraction (MVIC) states. (A): transversus abdominis (TrA); (B): diaphragm; (C): lumbar multifidus (MF)

Fig. 5

The percentage change of core muscles before and after interventions for patients with chronic low back pain in dynamic neuromuscular stabilization (DNS) and control groups. * indicates the significant difference between DNS and control groups after the intervention (p < 0.05). TrA, transversus abdominis; MF, multifidus

Fig. 6

Postural control performance in the eye-open condition before and after interventions for patients with chronic low back pain in dynamic neuromuscular stabilization (DNS) and control groups. No significant difference was observed between DNS and control groups before and after the intervention (p < 0.05). AP, anterior-posterior direction; COP, center of pressure; ML, medial-lateral direction

Fig. 7

Postural control performance in the eye-close condition before and after interventions for patients with chronic low back pain in dynamic neuromuscular stabilization (DNS) and control groups. * indicates the significant difference between DNS and control groups after the intervention (p < 0.05). AP, anterior-posterior direction; COP, center of pressure; ML, medial-lateral direction

Fig. 8

Results of clinical questionnaires for patients with chronic low back pain in dynamic neuromuscular stabilization (DNS) and control groups. No significant difference was observed between DNS and control groups before and after the intervention (p > 0.05). VAS, Visual Analogue Scale; RDQ, Roland Morris Disability Questionnaire; ODI, Oswestry Disability Index