Surface Electromyography (sEMG)

Download Clinical Summary PDF

Tool Description

  • Non-invasive technique used to measure muscle activity (both voluntary and involuntary) in individuals with neuromuscular conditions.

ICF Domain:

Body Function – Subcategory: Neuromusculoskeletal & Movement-related Functions and Structures

Number of Items:

n/a

Brief Instructions for Administration & Scoring

Administration:

  • Surface electrodes are placed on the skin overlying the muscles of interest.
  • Patients are instructed to voluntarily activate lower limb muscles to provide either maximal muscle strength or to perform simple movements (e.g. ankle flexion/extension).

Equipment:

  • Surface electrodes
  • Monitoring equipment.

Scoring: N/A.

Interpretability

MCID: not established in SCI
SEM: not established in SCI
MDC: not established in SCI

  • No normative values for the SCI population have been reported and interpretation of the data is not standardized.

Languages:

n/a

Training Required:

Special training is mandatory to conduct and interpret the results.

Availability:

n/a. Refer to references for various protocols in papers.

Clinical Considerations

  • sEMG recordings can complement the clinical examination specifically by providing objective and quantifiable measures of muscle activity. They have been shown to be valid in comparison to the clinical testing of motor strength and might be of highest value to monitor motor recovery in incomplete SCI.
  • As these measures need special training and equipment they will be most suitable in the frame of clinical research studies rather than for clinical day-to-day routine.
  • The technique is well tolerated and is much less intrusive than needle EMG, so there is minimal burden for patients. However, an EMG can range in cost from several hundred to over a thousand dollars depending on features, and requires skilled processing and interpretation.

Measurement Property Summary

# of studies reporting psychometric properties: 4

Reliability:

  • Correlation analysis results showed an moderate to high correlation for 3 repeated measures (r= 0.83-0.98 for magnitude, r= 0.77 to 0.88 for similarity index (SI)).
  • Flexion movements (r=0.95±0.03 for magnitude and r=0.86±0.03 SI) showed significantly higher correlation than extension movements (P<.05).

[Lim & Sherwood 2005]

Validity:

  • An SI value of 0.85 was found to separate AIS-C and AIS-D groups with a sensitivity of 0.89 and a specificity of 0.81.

[Calancie et al. 2000, Lim et al. 2005, Lim & Sherwood 2005, Lim et al. 2004]

Responsiveness:

No values have been reported at this time for the responsiveness of sEMG for the SCI population.

Floor/ceiling effect:

No values were reported for the presence of floor/ceiling effects in the sEMG for the SCI population.

Reviewer

Dr. Vanessa Noonan, Matthew Querée

Date Last Updated:

Feb 22, 2017

Download the measure

Download Worksheet:
n/a. sEMG protocols can be found in papers in the References section.

Video

n/a

Scoring

n/a

Equipment Needed

sEMG:

Calancie B, Molano MR, Broton JG, Bean JA, Alexeeva N. Relationship between EMG and muscle force after spinal cord injury. J Spinal Cord Med 2001;24:19-25.
http://www.ncbi.nlm.nih.gov/pubmed/11587429

Lim CL, Clouston P, Sheean G, Yiannikas C. The influence of voluntary EMG activity and click intensity on the vestibular click evoked myogenic potential. Muscle & Nerve, 2004; 18 (10): 1210-1213.
http://www.ncbi.nlm.nih.gov/pubmed/7659119

Lim HK, Lee DC, McKay WB, Priebe MM, Holmes SA, Sherwood AM. Neurophysiological assessment of lower-limb voluntary control in incomplete spinal cord injury. Spinal Cord 2005;43:283-290.
http://www.ncbi.nlm.nih.gov/pubmed/15672098

Lim HK, Sherwood AM. Reliability of surface electromyographic measurements from subjects with spinal cord injury during voluntary motor tasks. Journal of Rehabilitation Research & Development 2005;42:413-421.
http://www.ncbi.nlm.nih.gov/pubmed/16320138

Matheson DW, Toben TP, de la Cruz DE. EMG scanning: normative data. J Psychopathol Behav Assess 1988; 10(1):9-20. doi: 10.1007/BF00962981
http://link.springer.com/article/10.1007%2FBF00962981

Pullman SL, Goodin DS, Marquinez AI, Tabbal S, Rubin M. Clinical utility of surface EMG: report of the therapeutics and technology assessment subcommittee of the American Academy of Neurology. Neurology 2000;55:171-177.
http://www.ncbi.nlm.nih.gov/pubmed/10908886