Reference values have yet to be developed.

Researchers collect their own norms, such as individual norms or base levels for further comparisons. Using the device regularly allows for gaining such experience quickly. Depending on the research being conducted, healthy controls, placebo groups or the unaffected side in patients presenting with a unilateral condition can serve as a reference.

Typically, most superficial skeletal muscles of a healthy adult with the muscle of interest at full rest range from:

  • Oscillation frequency: 13...15 Hz;
  • Stiffness: 200...350 N/m (m. tibialis anterior usually presents with above average stiffness).

Quantitative values of measurement results are influenced by the following factors:

  • Muscle activation level (measure at full rest only as it allows for repeatability, the exact level of muscle contraction is not reliably repeatable);
  • Measurement point location (above muscle belly);
  • Muscle length (agonist and antagonist in balance, avoid full extension);
  • Body position (always prefer lying (if possible), this allows for full relaxation and easy repeatability);
  • Physical condition, general health status, medical condition, lifestyle, sports, occupation;
  • Fatigue and recovery status at the given moment;
  • BMI and adipose layer thickness;
  • Age, gender, blood pressure, stress level, temperature.

It is crucially important to always use the same conditions and a standardised setup when collecting measurements.

The development of reference values is a challenging task but can certainly be accomplished. The project would require international scientific collaboration to establish and describe classification criteria. A large multi-centre study is necessary with data collected from diverse populations.