In daily clinical practice, chiropractors frequently encounter challenging cases involving the diagnosis and treatment of the nervous system, both at a spinal level and from the spine outwards, exiting peripherally into the hands and feet. With the majority of patients who present to a chiropractor being head, neck and back pain, there can be a significant percentage of those who concurrently suffer from concomitant weakness, tingling, numbness and various other neurogenic symptoms.
Chiropractors and physiotherapists have undertaken an extensive level of training in conducting a neurological examination to determine what level of the spine is contributing to compression of a nerve. This often requires distinguishing between lesions that are located in the brain or spinal cord and those in the peripheral nerves. Making the correct diagnosis can be challenging and choosing the right diagnostic tools is critical. Whilst conducting a neurological examination is central in determining if the disc bulge or protrusion is affecting the nerve roots exiting the spine, Magnetic Resonance Imaging (MRI) is widely regarded as a gold standard for visualising and confirming or identifying space-occupying lesions, demyelination, inflammation, vascular abnormalities or degenerative changes as well as rule out the possibility of more serious pathologies such as inflammatory or cancerous lesions. Unfortunately, there are a lot of patients and even more so, clinicians, who are unsatisfied with the correlation between patient symptoms (weakness, tingling / numbness and pain) and MRI findings. The most favourable explanation would be one where symptoms match the MRI report. Unfortunately this is far from reality.
MRI alone has limitations in the correlation between patient symptoms with the prognosis, severity and clinical location of a nerve that is compressed by a protruded disc in the neck or back. It primarily reveals structural abnormalities and cannot always detect subtle or functional impairments in the nervous system.
A normal MRI does not necessarily rule out nerve dysfunction.
Sydney Neuro & Integrative health places heavy emphasis on filling in this gap with the use of standardised, state-of-the-art diagnostic equipment to add significant value to the understanding, monitoring and treatment of a condition. With respect to a patient with back pain, neurogenic symptoms of weakness, tingling or numbness down the leg, Sydney Neuro & Integrative Health utilises Nerve Conduction Studies (NCS) and Electromyography (EMG) Studies to directly measure the function of peripheral nerves and muscles to complement examination and MRI findings. This powerful addition is very rare in allied health clinics – in fact we are likely one of the only clinics in the country which combine all of these diagnostic capabilities.
What is Electrodiagnostic Testing (NCV/EMG)?
Electrodiagnostic testing (NCV/EMG) refers to a group of tests used to evaluate the function of nerves and muscles. The NCV (Nerve Conduction Velocity) portion involves using a cathode and anode to stimulate a nerve, while recording electrodes measure the muscle’s response to this stimulation.
Typically, three parameters are assessed: latency, velocity and amplitude.
Each of these parameters helps identify which part of the nerve is affected – for example, myelin damage as seen in multiple sclerosis, axonal injury as in motor neurone disease, or longstanding compression from a disc herniation.
The EMG (Electromyography) component involves inserting a needle, slightly thicker than an acupuncture needle, into a muscle of interest to record electrical activity. EMG can detect subtle pathological processes, such as early signs of fatal diseases or initial nerve compression from a disc that may not yet present with classical symptoms like “sciatica.”
Together, NCV/EMG testing can essentially determine the severity, location and type of nerve damage, as well as provide prognostic information regarding appropriate timing for re-innervation and recovery. As a primary setting within a chiropractic clinic, these tests are particularly useful for monitoring the effectiveness of interventions and objectively assessing patient recovery. They can also help determine whether surgery or other treatments may be required. Post-surgery, NCV/EMG can be used periodically to evaluate nerve recovery from an objective standpoint. NCV/EMG testing is commonly performed in neurology departments within hospitals.
Incorporating Nerve Conduction Velocity (NCV) and Electromyography (EMG) Testing in Clinical Practice
Incorporating NCV and EMG testing into a chiropractic practice significantly enhances diagnostic precision and patient care. These neurodiagnostic tools provide objective, quantifiable data on nerve and muscle function, enabling differentiation between radiculopathy, peripheral neuropathy and other neuromuscular conditions that often present with overlapping symptoms.
By integrating NCV/EMG studies, Sydney Neuro & Integrative Health can develop more targeted treatment plans, justify the medical necessity of care and improve interprofessional communication with neurologists, primary care providers and insurers. Most importantly, they allow us to correlate MRI findings with clinical symptoms to determine the true relevance of imaging results. This not only elevates clinical outcomes but also strengthens the practice’s role in comprehensive musculoskeletal and neurological healthcare.
Scientific literature strongly supports the use of NCV/EMG alongside MRI – and in some cases, NCV/EMG may be preferable in certain clinical scenarios.
Lo et al., in Clinical Neurology and Neurosurgery, stated:
“Combined utilization of multiple F-wave parameters is a useful, diagnostic adjunct in the electrophysiological evaluation of cervical spondylolytic myelopathy. F-wave is non-specific to a root level, but F-wave parameters (minimal F-wave latency, F-wave persistence, and F-wave chronodispersion) with needle EMG provide greater evaluative function.”
This highlights how NCV/EMG can provide meaningful context to MRI findings when assessing nerve root compression grading.
Similarly, Chiodo et al., in the Journal of Physical Medicine and Rehabilitation, showed that an absent tibial H-wave and prolonged peroneal F-wave significantly correlated with relevant lumbar central canal stenosis locations.
In Muscle & Nerve, McDonald et al. found:
“Increased signal intensity on STIR MRI corresponds closely with spontaneous activity on EMG in denervated muscle. Although less sensitive than EMG in detecting muscle denervation, STIR MRI may be a useful adjunctive diagnostic tool.”
STIR MRI (Short Tau Inversion Recovery MRI) suppresses fat signal, making areas of increased fluid or inflammation easier to visualise. However, denervation of a nerve root cannot be inferred by MRI alone – EMG is more sensitive in detecting denervation, which has clinical consequences over time (e.g., progressive weakness, altered gait, bowel or bladder changes). This reinforces that structural compression seen on MRI does not necessarily equate to muscle denervation.
Regarding neck pain and cervical MRI findings, Nicotra et al., in the Journal of Neurosurgery, reported:
“The high false-positive rate of magnetic resonance imaging (MRI) makes it a less-than-reliable tool for evaluating clinically significant stenosis. Finding MRI changes that correlate with electrodiagnostic abnormalities might lead to more successful treatment decision making. When discrepancies exist, EMG can help determine which patients are most likely to benefit from surgical intervention by indicating which nerve roots are functionally impaired.”
EMG can therefore determine the importance on appropriate timing and planning for surgical intervention.
In the European Spine Journal, Alwari et al. found that needle EMG correlated with nerve root injury at surgery in 79% of patients, based on the presence of fibrillations and positive sharp waves in limb muscles. EMG findings at both one year and five years following surgical decompression were associated with good clinical outcomes. The study also showed that, across all patients with radiculopathy, moderate improvement was achieved after anterior discectomy and fusion at levels indicated by clinical symptoms and MRI. However, a significantly greater improvement occurred in patients who also demonstrated abnormalities on needle EMG. This indicates that the best surgical candidates are likely those with positive EMG findings. While abnormal neurophysiological results should not be the sole criterion for surgery, they can improve the likelihood of predicting which patients will benefit. Conversely, patients with normal neurophysiological tests should be counselled preoperatively that any postoperative symptom improvement may be limited. Notably, patients with preoperative EMG evidence of cervical nerve root involvement achieved better outcomes following discectomy and anterior fusion than those without such findings.
This underscores the importance of grading denervation via EMG to assess surgical candidacy – something MRI alone cannot determine.
Perhaps the most profound journal title that justifies the use of NCV/EMG in clinical practice is the one written by Singh et al., in the Asian Journal of Neurosurgery, where the author evaluated the correlation between MRI and electrodiagnostic (EDX) findings in chronic low back pain patients, concluding:
“First, EMG demonstrated a more significant correlation with poorer functionality of lower limb (evident by decreased recruitment in all the three tested muscles) than did MRI in the disc involved patients. This was explained by the fact that EMG abnormalities were dependent on the loss of motor axons. Second, EMG was more correlated with the signs and symptoms of the patients and tells more about the functional status of the nerves and muscles. It has higher specificity and lower level of false positivity and hence can play an important role in steering patients toward appropriate treatments. Third, EMG could also be used to identify the level of disc involvement in patients of radiculopathy”.
Therefore EDX gives a better representation of physiological status of nerve and muscle, a significantly added benefit which MRI lacks. However, MRI gives better visualisation of anatomic parameters and structural details which may or may not be associated with chronic LBP.
Coster et al., in Diagnostic Value of History, Physical Examination and Needle Electromyography in Diagnosing Lumbosacral Radiculopathy, noted that EMG can detect nerve root involvement even when MRI appears normal, helping explain clinical symptoms such as weakness or tingling:
“In clinical practice, dermatomal radiation, more pain on coughing, sneezing or straining, positive straight leg raising and ongoing denervation on EMG may be used to predict nerve root compression on MRI. EMG may also be of additional value in patient with clinical suspicion of lumbosacral radicular syndrome without nerve root involvement on MRI”.
Furthermore, in the article Walking capacity and EMG findings in patients with surgically confirmed lateral lumbar spinal canal stenosis, the authors reported that visually assessed measures – including entrance stenosis severity, mid-zone stenosis severity, entrance zone width and mid-zone area – did not correlate with patients’ clinical symptoms. However, these anatomical parameters did correlate with abnormal EMG findings and higher scores on the Visual Analogue Scale (VAS). Abnormal EMG was also associated with the severity of mid-zone stenosis on visual assessment.
Finally, Yousif et al. concluded that while anatomical abnormalities identified by MRI can aid in surgical planning, nerve conduction studies (NCS) are valuable for determining the severity of nerve root damage and for postoperative follow-up. MRI remains a sensitive tool for detecting structural lesions, whereas NCS evaluates physiological changes in nerve function. Notably, there was no statistically significant association between physical examination findings (e.g., abnormal gait, absent ankle jerk, impaired sensation, positive straight leg raise) and MRI-confirmed nerve root compression – consistent with previous studies. In addition, MRI revealed a higher number of abnormalities than electrodiagnostic testing (EDX) at clinically irrelevant levels.
These studies reinforce that anatomical MRI parameters often do not correlate with symptoms, whereas abnormal EMG findings show stronger associations with patient pain scores and functional limitations.
From a clinical perspective, it is common for patients to present with two or more neuromusculoskeletal conditions simultaneously. For example, a patient may have both C7 nerve root compression and carpal tunnel syndrome – conditions that MRI alone cannot reliably differentiate. In contrast, NCV/EMG can distinguish between:
1 Radiculopathy and peripheral neuropathy
2 Plexopathy and mononeuropathy
3 Functional and organic weakness
This makes NCV/EMG a valuable complement to MRI in the chiropractic and multidisciplinary clinical setting.
In the present study, no statistically significant correlation was found between MRI and NCS findings. It is therefore reasonable to add electrodiagnostic testing (EDX) when MRI and clinical findings disagree, or when MRI fails to detect neurologic abnormalities. In certain cases – such as non-compressive radiculopathy -EDX may reveal abnormalities even when neuroimaging does not identify certain pathology. Another important advantage is that MRI cannot quantify the degree of axonal loss and therefore cannot directly predict prognosis, in contrast to EDX, which has this capability.
While MRI offers a detailed anatomical snapshot – identifying structural abnormalities that can influence surgical or interventional decisions – its correlation with the severity or presence of clinical symptoms often proves weak or inconsistent. In contrast, electrodiagnostic techniques, including EMG and NCS, assess the function and integrity of nerves, frequently yielding a stronger association with a patient’s reported pain, motor deficits or sensory changes. MRI can reveal anatomical abnormalities (e.g., disc bulges, stenosis) even in asymptomatic individuals, whereas NCV/EMG helps determine whether these findings are clinically relevant!
This suggests that, especially in conditions such as radiculopathy or spinal canal stenosis, incorporating NCV/EMG alongside MRI provides the most accurate and actionable understanding of the underlying pathology, ultimately guiding patients toward better-targeted treatment and improved outcomes.
The above picture illustrates an absent Soleus Left H-wave. This patient has absolutely no response at the soleus despite multiple treatments from chiropractors and physiotherapists. This suggest the need for surgical decompression in which the patient was later admitted to.
The table below summarises the key differences between MRI and NCV/EMG. It clearly illustrates how combining both modalities offers far greater diagnostic and prognostic value than relying on MRI alone, particularly for persistent spine and nerve-related disorders.
Are you treating patients with progressive lumbosacral or cervical radiculopathy whose MRI findings don’t fully explain their symptoms?
A targeted electrodiagnostic evaluation can bridge that gap – helping to clarify diagnosis, guide treatment and support timely surgical referrals when appropriate.
I’m offering a free 10-minute consultation to discuss how EMG and nerve conduction studies can complement MRI, uncover clinically relevant nerve dysfunction and provide valuable insight into the chronicity and severity of your patient’s condition.
Click HERE to schedule your consultation and take the next step toward more accurate, evidence-based care.