The effects of spinal manipulative therapy on lower limb neurodynamic test outcomes in adults: a systematic review

Abstract

Objective: Spinal Manipulative Therapy (SMT) is a routinely applied treatment modality for various musculoskeletal conditions, including low back pain. The precise mechanisms by which SMT elicits its effects are largely unknown, but recent research supports a multi-system explanation recognizing both biomechanical and neurophysiological mechanisms. Although the evaluation of changes in clinical presentation is complex, objective neurophysiological measures of sensitivity to movement (e.g. neurodynamic tests) can be a valuable clinical indicator in evaluating the effects of SMT. This review aimed to synthesize current literature investigating the effects of SMT on lower limb neurodynamics. Method: Eight electronic databases were systematically searched for randomized controlled trials (RCT) that applied SMT (against any control) and evaluated lower limb neurodynamics (Passive Straight Leg Raise or Slump Test). Selection and data extraction were conducted by one researcher, reviewed by a second author. Risk of bias (RoB) was assessed using the Cochrane Back Review Group criteria. Results: Eight RCTs were included, one with high RoB. SMT produced a clinically meaningful (≥6⁰) difference in five of these studies compared with inert control, hamstring stretching, and as an adjunct to conventional physiotherapy, but not compared with standard care, as an adjunct to home exercise and advice, or when comparing different SMT techniques. Findings compared to sham were mixed. When reported, effects tentatively lasted up to 6 weeks postintervention. Conclusion: Limited evidence suggests SMT-improved range of motion and was more effective than some other interventions. Future research, using standardized Neurodynamic tests, should explore technique types and evaluate longer-term effects. Level of Evidence: 1a

Efficacy of manual therapy on psychological status and pain in patients with neck pain

“…9 Several authors confirmed that MT has analgesic effects on pain. 1,6,[10][11][12][13][14][15][16] The underlying mechanisms of pain reductions after MT may be due to the influence of analgesic mediations and sympatho-excitatory effects through the activation of large-diameter, low-threshold mechanoreceptors, which in turn results in inhibition at the spinal cord level, according to the gate control theory of pain. Activation of the dorsal periaqueductal grey matter is used to control the motivational states through the release of serotonin and nor-adrenaline from the descending neurons.…”

“…Activation of the dorsal periaqueductal grey matter is used to control the motivational states through the release of serotonin and nor-adrenaline from the descending neurons. 12 At the same time, reductions in neck pain have positive impacts on functional activity and reductions of the neck functional disability index. 20 In contrast with the current study's findings, some authors found that SNAGs of MT did not induce any benefit in neck pain and the functional disability index.…”

“… 11 Manual therapy activates the sympathetic nervous system and has extended analgesic effects beyond the specific body segment receiving the treatment. 12 Maitland and Mulligan mobilization techniques are commonly used types of MT in clinical practice. 11 A better outcome is expected after a mobilization intervention under high anxiety levels, whereas a better prognosis is expected after manipulation and sustained natural apophyseal glides (SNAGs) under low anxiety levels.…”

A spinal manipulative therapy altered brain activity in patients with lumbar disc herniation: A resting-state functional magnetic resonance imaging study

“…Until now, SMT has been utilized to restore the structure of disordered spines and unstable spinal balance, improve the physiological properties of muscles, moderate the internal stress of intervertebral discs, and alleviate intervertebral disc compression of the nerve root, therefore, it could reach the goal of stopping pain and restoring the function of the local spinal column ( Maigne and Vautravers, 2003 ; Bredow et al, 2016 ). A relevant systemic review has shown that SMT had a favorable effect on alleviating pain and speeding up the recovery, compared with other interventions for LDH patients ( Maxwell et al, 2020 ). A prospective observational cohort study with a 1-year follow-up also has indicated that a large percentage of acute and chronic LDH patients treated with SMT have been reported clinically relevant improvement ( Leemann et al, 2014 ).…”

A systematic review of chiropractic care for fall prevention: rationale, state of the evidence, and recommendations for future research

“…There is evidence to support that components of multimodal chiropractic care can improve musculoskeletal flexibility, with limited studies evaluating the impact of SM alone on flexibility. One systematic review concluded that some short-term SM protocols result in clinically meaningful improvements in hamstring flexibility [ 62 ]. Another recent meta-analysis, evaluating the impact of cervical high-velocity low-amplitude manipulation reported a large positive effect on cervical ROM [ 45 ].…”