Clinical Policy Bulletin: Surface Scanning and Macro Electromyography
Aetna considers surface scanning electromyography (EMG), paraspinal surface EMG, or macro EMG experimental and investigational as a diagnostic test for evaluating low back pain or other thoracolumbar segmental abnormalities such as soft tissue injury, intervertebral disc disease, nerve root irritation and scoliosis, and for all other indications because the reliability and validity of these tests have not been established.
Aetna considers surface EMG devices experimental and investigational for diagnosis and/or monitoring of nocturnal bruxism and all other indications because the reliability and validity of these tests have not been demonstrated.
Aetna considers spinoscopy (Spinoscope, Spinex Corp.), a diagnostic technique that combines surface scanning EMG with video recordings, experimental and investigational as the clinical value of this diagnostic technique has not been validated.
Note: Surface scanning EMG should not be confused with conventional needle EMG, nor with the use of surface electrodes in EMG biofeedback techniques, which are considered medically necessary for appropriate indications.
Surface scanning electromyography (EMG) is different from the conventional needle EMG. Surface scanning EMG employs a scanner with self-contained electrodes and/or surface electrodes that are applied to the skin, and record a specific muscle or group of muscles' electrical potential. There have been attempts to use this technology to diagnose back pain, soft tissue injury, temporomandibular joint dysfunction, nerve root irritation, and scoliosis.
Paraspinal EMG is a type of surface scanning EMG that has been used in evaluation of back pain. The rationale for the use of surface scanning EMG in the evaluation of low back pain (LBP) appears to be based on the notion that there is a direct relationship between muscular pain and elevated myoelectrical behaviors. However, some investigators have reported no differences in paraspinal EMG levels as a function of pain state in patients with LBP, and a review of the literature indicates that the relationship between increased EMG activity and the diagnosis/severity of LBP is still highly controversial.
To date, surface scanning EMG has not been proven to be effective as a diagnostic tool in the evaluation of LBP and other thoracolumbar segmental abnormalities. The field of scanning EMG is only at the beginning of understanding the characteristics of the surface EMG signal and its relationship to impairment. Further investigation is needed before this technology can be used in a clinical setting.
Systematic evidence reviews supporting the use of surface EMG have suffered from substantial limitations. Mohseni-Bandpei et al (2000) reported on a literature review of surface EMG in the diagnosis of LBP. The authors found that substantial variation in the included studies regarding the methodology, procedure, type of muscle contraction, sample size, and the duration, degree and source of the patients' pain. "However, based on this review, there appears to be convincing evidence that SEMG is a reliable and valid tool for differentiating LBP patients from normal people and for monitoring rehabilitation programmes." A critical assessment of the review by Mohensi-Bandpei et al by the Centre for Reviews and Dissemintation (2003) found that "[t]he information presented does not provide adequate support for the authors' conclusions." The study by Mohensi-Bandpei et al was criticized on a number of counts: (i) the methods used to select the studies were not reported and validity was not formally assessed; (ii) the methods used to extract the data were not described; (iii) the studies were combined by counting the number of studies classified as having positive or negative conclusions without assessing the validity of the original authors' conclusions; (iv) the review contained insufficient details of the methods used to conduct the review, and no information on the internal or external validity of the results; and (v) the review examined whether the surface EMG levels were different in people with LBP and "normals", rather than assessing the diagnostic accuracy of surface EMG in LBP.
A more recent evidence review of surface EMG suffers from many of these same limitations. Based on a review of the evidence, Geisser et al (2005) found that some surface EMG measures had the potential to distinguish between people with and without LBP. A critical review of the study by Geisser et al by the Centre for Reviews and Dissemintation stated that "[t]hese findings should be interpreted with extreme caution given the limitations in the search and analysis, and the failure to assess study quality and report review methods." The CRD found that the literature search by Geisser et al was limited to 1 database and no attempts were made to identify unpublished studies. "It was therefore likely that relevant studies had been missed and the review may be subject to publication bias." The CRD review also noted that the quality of the included studies was not assessed, so it was not possible to assess the validity of the findings. The CRD review also found that details of the review process were not reported, "thus it was unclear whether appropriate steps were taken to minimise bias." The CRD review also found that the methods used to pool the data "were not reported clearly and did not seem appropriate for the calculation of summary sensitivity and specificity, which appeared simply to be an average value." The CRD review found that, where multiple comparison groups shared a control group, no adjustment for statistical dependency was made. The CRD review also found that the range of reported diagnostic values suggested that results were not always consistent among studies and that pooling may not have been appropriate. "In view of the lack of reporting of review methods, the lack of a quality assessment of the included studies, differences between the studies and concerns about the methods of analysis, the authors' conclusions may not be reliable."
Surface EMG has also been attempted to diagnose and monitor nocturnal bruxism. Bruxism (the grinding and clenching of teeth) causes abnormal wear of the teeth, sounds associated with bruxism, and jaw muscle discomfort. Portable EMG units are available for use by patients in the home, and involve placement of electrodes on the skin over the muscle being studied (e.g., masseter). Self-monitoring recordings can be imprecise due to recording problems, inconsistent and improper electrode placement, and the collection of muscle activity not associated with occlusal pressure (e.g., oral activity such as yawning and swallowing). An EMG is not required to diagnose bruxism as the consequences of this condition can be observed clinically during a regular dental examination.
Spinoscopy is a testing and analysis procedure that uses a Spinex Spinoscope® System to evaluate the functional status of the back. The Spinoscope is a computer-driven multi-camera video and EMG system that records vertebral movement and the corresponding muscular activity during movements of the back. Spinoscopy has been used to track the coordination of the back and identifies the conditions under which that coordination breaks down. The value of spinoscopy evaluation in diagnosing and monitoring patients with back problems and ultimately improving their outcomes has not been demonstrated in the published peer-reviewed medical literature.
Leclaire and colleagues (1996) examined the diagnostic accuracy of four technologies (namely clinical examination, spinoscopy, thermography, and tri-axial dynamometry) in assessing LBP. A total of 41 patients and 46 control subjects were assessed by each technology and by 2 clinical examiners blind to clinical status. Twenty patients were trained to simulate a healthy back without LBP, and 50 % of the control subjects were trained to simulate the presence of a LBP disorder. Each technology was interpreted on 2 occasions by each of 2 readers. Thermography performed significantly worse than did tri-axial dynamometry, spinoscopy, and clinical examination. The diagnostic accuracy of the last 3 was similar, and inter-rater comparability did not differ significantly. Among simulators, the diagnostic accuracy of spinoscopy and tri-axial dynamometry was significantly higher than that of clinical examination, although considerable inaccuracy remained in assessing individual subjects. The authors concluded that the diagnostic accuracy of thermography in recent onset LBP does not support its use. Among those simulating normality or LBP, spinoscopy and tri-axial dynamometry have greater diagnostic accuracy than does a single clinical evaluation. However, for an individual, the inaccuracy that remains limits the use of spinoscopy or tri-axial dynamometry for diagnosis in recent onset LBP.
Furthermore, in a best-evidence review of diagnostic procedures for LBP and neck pain (Rubinstein and van Tulder, 2008), spinoscopy was not mentioned as a diagnostic option for these conditions.
Fuglsang-Frederiksen (2006) evaluated different EMG methods in the diagnosis of myopathy. These include manual analysis of individual motor unit potentials and multi-motor unit potential analysis sampled at weak effort. At high effort, turns-amplitude analyses such as the cloud analysis and the peak ratio analysis have a high diagnostic yield. The EMG can seldom be used to differentiate between different types of myopathy. In channelopathies and myotonia, exercise testing and cooling of the muscle are helpful. Macro-EMG, single-fiber EMG and muscle fiber conduction velocity analysis have a limited role in myopathy, but provide information about the changes seen. The authors concluded that analysis of the firing rate of motor units, power spectrum analysis, as well as multi-channel surface EMG may have diagnostic potential in the future.
Sanger (2008) presented the findings of a pilot study on the use of a portable surface EMG device for the evaluation of childhood hypertonia. A total of 7 children aged 5 to 17 years with hypertonia due to cerebral palsy were each examined by 6 clinicians, both with and without the use of surface EMG. The use of surface EMG resulted in an increase in inter-rater agreement as well as an increase in the self-reported confidence of the clinicians in their assessment. The authors concluded that these results support the importance of further testing of surface EMG as an adjunct to the clinical examination of childhood hypertonia.
The Work Loss Data Institute's clinical guidelines on "Low back - lumbar & thoracic (acute & chronic)" (2011) and "Neck and upper back (acute & chronic) (2011) do not recommend the use of surface EMG.
In a meta-analysis, Perinetti et al (2011) evaluated the scientific evidence for detectable correlations between the masticatory system and muscle activity of the other body districts, especially those mainly responsible for body posture via the use of surface EMG . A literature survey was performed using the PubMed database, covering the period from January 1966 to April 2011, and choosing medical subject headings. After selection, 5 articles qualified for the final analysis. One study was judged to be of medium-quality, the remaining 4 of low-quality. No study included a control group or follow-up; in only 1 study, subjects with impairment of the masticatory system were enrolled. In all studies, detectable correlations between the masticatory systems and muscle activity of the other body districts, or vice versa, were found; however, after a re-appraisal of the data provided in these studies, only weak correlations were found, which reached biological, but not clinical relevance. With the limitations that arise from the poor methodological quality of the published studies discussed here, the conclusion was that a correlation between the masticatory system and muscle activity of the other body districts might be detected through surface EMG under experimental conditions; however, this correlation has little clinical relevance. While more investigations with improved levels of scientific evidence are needed, the current evidence does not support clinically relevant correlations between the masticatory system and the muscle activity of other body districts, including those responsible for body posture.
CPT Codes / HCPCS Codes / ICD-9 Codes
CPT codes not covered for indications listed in the CPB:
HCPCS codes not covered for indications listed in the CPB:
Surface electromyography (EMG)
ICD-9 codes not covered for indications listed in the CPB (not all-inclusive):
Other specified psychophysiological malfunction [nocturnal bruxism]
353.0 - 353.9
Nerve root and plexus disorders
355.0 - 355.9
722.0 - 722.93
Intervertebral disc disorders
724.00 - 724.9
Other and unspecified disorders of back [low back pain]
737.30 - 737.39
Kyphoscoliosis and scoliosis
Scoliosis associated with other conditions
Sprains and strains of other and unspecified parts of back, thoracic
Sprains and strains of other and unspecified parts of back, lumbar
Contusion of back
Other injury of other sites of trunk [back]
The above policy is based on the following references:
Waddell G. A new clinical method for the treatment of low-back pain. Spine. 1987;12:632-642.
Glantz RH, Haldeman S. Other diagnostic studies: Electrodiagnosis. In: The Adult Spine. Principles and Practice. Vol. I. JW Frymoyer, ed. New York, NY: Raven Press; 1991; Ch. 26: 541-548.
Arena JG, Sherman RA, Bruno GM, Young TR. Electromyographic recordings of low back pain subjects and non-pain controls in six different positions: Effects of pain levels. Pain. 1991;45(1):23-28.
Arena JG, Bruno GM, Brucks AG, et al. Reliability of an ambulatory electromyographic activity device for musculoskeletal pain disorders. Int J Psychophysiol. 1994:17(2):153-157.
Leach RA, Owens EF Jr, Giesen JM. Correlates of myoelectric asymmetry detected in low back pain patients using hand-held post-style surface electromyography. J Manipulative Physiol Ther. 1993:16(3):140-149.
Triano JJ, et al. The use of instrumentation and laboratory examination procedures by the chiropractor. In: Principles and Practice of Chiropractic. 2nd ed. S Haldeman, ed. Stamford, CT: Appleton & Lange; 1992; Ch. 20: 319-360.
Triano JJ. The subluxation complex: Outcome measure of chiropractic diagnosis and treatment. Chiro Technique. 1990;2:114-120.
Boline PD, Haas M, Meyer JJ, et al. Interexaminer reliability of eight evaluative dimensions of lumbar segmental abnormality: Part II. J Manipulative Physiol Ther. 1993;16(6):363-374.
Meyer JJ. The validity of thoracolumbar paraspinal scanning EMG as a diagnostic test: An examination of the current literature. J Manipulative Physiol Ther. 1994;17:539-551.
McMaster University Health Science Center, Department of Clinical Epidemiology and Biostatistics. How to read clinical journals: II: To learn about a diagnostic test. Can Med Assoc J. 1981;124:703-710.
Ng JK, Richardson CA. Reliability of electromyographic power spectral analysis of back muscle endurance in healthy subjects. Arch Phys Med Rehabil. 1996;77(3):259-264.
Longstreth WT Jr, Koepsell TD, van Belle G. Clinical neuroepidemiology I: Diagnosis. Arch Neurol. 1987;44(10):1091-1099.
Myerowitz M. Scanning paraspinal surface EMG: A method for corroborating post-treatment spinal and related neuromusculoskeletal symptom improvement. J Occup Rehabil. 1994;4(3):171-179.
Greenough GC, Oliver CW, Jones AP. Assessment of spinal musculature using surface electromyographic spectral color mapping. Spine. 1998;23(16):1768-1774.
Oddsson LI, Giphart JE, Buijs RJ, et al. Development of new protocols and analysis procedures for the assessment of LBP by surface EMG techniques. J Rehabil Res Dev. 1997;34(4):415-426.
Kollmitzer J, Ebenbichler GR, Kopf A. Reliability of surface electromyographic measurements. Clin Neurophysiol. 1999;110(4):725-734.
Wolf LB, Segal RL, Wolf SL, et al. Quantitative analysis of surface and percutaneous electromyographic activity in lumbar erector spinae of normal young women. Spine. 1991;16(2):155-161.
Moritani T, Yoshitake Y. 1998 ISEK Congress Keynote Lecture: The use of electromyography in applied physiology. International Society of Electrophysiology and Kinesiology. J Electromyogr Kinesiol. 1998;8(6):363-381.
Roy SH, Oddsson LI. Classification of paraspinal muscle impairments by surface electromyography. Phys Ther. 1998;78(8):838-851.
Roy SH, De Luca CJ, Casavant DA. Lumbar muscle fatigue and chronic lower back pain. Spine. 1989;14(9):992-1001.
Roy SH, De Luca CJ, Emley M, et al. Classification of back muscle impairment based on the surface electromyographic signal. J Rehabil Res Dev. 1997;34(4):405-414.
De Luca CJ. Use of the surface EMG signal for performance evaluation of back muscles. Muscle Nerve. 1993;16(2):210-216.
Airaksinen O, Airaksinen K. Ambulatory device for surface EMG recordings. Acupunct Electrother Res. 1998;23(1):9-17.
Sihvonen T, Partanen J, Hanninen O, et al. Electric behavior of low back muscles during lumbar pelvic rhythm in low back pain patients and healthy controls. Arch Phys Med Rehabil. 1991;72(13):1080-1087.
Jalovaara P, Niinimaki T, Vanharanta H. Pocket-size, portable surface EMG device in the differentiation of low back pain patients. Eur Spine J. 1995;4(4):210-212.
Roy SH, De Luca CJ, Emley M, et al. Spectral electromyographic assessment of back muscles in patients with low back pain undergoing rehabilitation. Spine. 1995;20(1):38-48.
Lee DJ, Stokes MJ, Taylor RJ, et al. Electro and acoustic myography for noninvasive assessment of lumbar paraspinal muscle function. Eur J Appl Physiol. 1992;64(3):199-203.
Traue HC, Kessler M, Cram JR. Surface EMG topography and pain distribution in pre-chronic back pain patients. Int J Psychosom. 1992;39(1-4):18-27.
Cram JR, Steger JC. EMG scanning in the diagnosis of chronic pain. Biofeedback Self Regul. 1983;8(2):229-241.
Krivickas LS, Taylor A, Maniar RM, et al. Is spectral analysis of the surface electromyographic signal a clinically useful tool for evaluation of skeletal muscle fatigue? J Clin Neurophysiol. 1998;15(2):138-145.
Sparto PH, Parnianpour M, Reinsel TE, et al. Spectral and temporal responses of trunk extensor electromyography to an isometric endurance test. Spine. 1997;22(4):418-426.
Kankaanpaa M, Taimela S, Laaksonen D, et al. Back and hip extensor fatigability in chronic low back pain patients and controls. Arch Phys Med Rehabil. 1998;79(4):412-417.
Kankaanpaa M, Taimela S, Webber CL Jr, et al. Lumbar paraspinal muscle fatigability in repetitive isoinertial loading: EMG spectral indices, Borg scale and endurance time. Eur J Appl Physiol. 1997:76(3):236-242.
Academy of General Dentistry (AGD). Bruxism (tooth grinding). AGD Consumer Information. Chicago, IL: AGD; 2001. Available at: http://www.agd.org/consumer/topics/bruxism.html. Accessed July 12, 2001.
Hudzinski LG, Walters PJ. Use of a portable electromyogram integrator and biofeedback unit in the treatment of chronic nocturnal bruxism. J Prosthet Dent. 1987;58(6):698-701.
Hemingway MA, Biedermann HJ, Inglis J. Electromyographic recordings of paraspinal muscles: Variations related to subcutaneous tissue thickness. Biofeedback Self Regul. 1995;20(1):39-49.
Mohseni-Bandpei MA, Watson MJ, Richardson B. Application of surface electromyography in the assessment of low back pain: A literature review. Physical Ther Rev. 2000;5(2):93-105.
Centre for Reviews and Dissemintation (CRD). Application of surface electromyography in the assessment of low back pain: A literature review. Database of Abstracts of Reviews of Effects (DARE). Accession No. 12000008694. York, UK: University of York; February 28, 2003.
Cengiz B, Ozdag F, Ulas UH, et al. Discriminant analysis of various concentric needle EMG and macro-EMG parameters in detecting myopathic abnormality. Clin Neurophysiol. 2002;113(9):1423-1428.
Hogrel JY. Clinical applications of surface electromyography in neuromuscular disorders. Neurophysiol Clin. 2005;35(2-3):59-71.
Geisser ME, Ranavaya M, Haig AJ, et al. A meta-analytic review of surface electromyography among persons with low back pain and normal, healthy controls. J Pain. 2005;6(11):711-726.
Centre for Reviews and Dissemintation (CRD). A meta-analytic review of surface electromyography among persons with low back pain and normal, healthy controls. Database of Abstracts of Reviews of Effects (DARE). Accession No. 12005002229. York, UK: University of York; January 31, 2008.
Fuglsang-Frederiksen A. The role of different EMG methods in evaluating myopathy. Clin Neurophysiol. 2006;117(6):1173-1189.
Sanger TD. Use of surface electromyography (EMG) in the diagnosis of childhood hypertonia: A pilot study. J Child Neurol. 2008;23(6):644-648.
Leclaire R, Esdaile JM, Jéquier JC, et al. Diagnostic accuracy of technologies used in low back pain assessment. Thermography, triaxial dynamometry, spinoscopy, and clinical examination. Spine. 1996;21(11):1325-1330; discussion 1331.
Rubinstein SM, van Tulder M. A best-evidence review of diagnostic procedures for neck and low-back pain. Best Pract Res Clin Rheumatol. 2008;22(3):471-482.
Work Loss Data Institute. Low back - lumbar & thoracic (acute & chronic). Encinitas, CA: Work Loss Data Institute; 2011.
Work Loss Data Institute. Neck and upper back (acute & chronic). Encinitas,CA: Work Loss Data Institute; 2011.
Perinetti G, Turp JC, Primozic J, et al. Associations between the masticatory system and muscle activity of other body districts. A meta-analysis of surface electromyography studies. J Electromyogr Kinesiol. 2011;21(6):877-884.
Copyright Aetna Inc. All rights reserved. Clinical Policy Bulletins are developed by Aetna to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. This Clinical Policy Bulletin contains only a partial, general description of plan or program benefits and does not constitute a contract. Aetna does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Aetna or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. This Clinical Policy Bulletin may be updated and therefore is subject to change.