Can mechanical myotonometry or electromyography be used for the prediction of intramuscular pressure?

Abstract

The aim of the study was to characterize the electromechanical properties of skeletal muscle during isometric loading as well as to assess the potential of estimating intramuscular pressure by electrical and mechanical methods. Simultaneous electromyography (EMG), mechanical myotonometry (MYO, frequency and decrement of decay) and intramuscular pressure (IMP) measurements were conducted at rest and during short-term and long-term isometric contractions in patients with chronic pain in the anterior leg or dorsal forearm. The EMG amplitude and MYO(freq) accounted significantly (24-73%, p < 0.0001) for the variations in the IMP under short-term isometric loading. The IMP, EMG and MYO(freq) increased linearly with the relative muscle load (r = 0.868-0.993, p < 0.05). Mean values of EMG amplitudes at the contraction levels of 75% and 100% maximum voluntary contraction (MVC) and MYO(freq) values at all contraction levels (0-100% MVC) were higher for subjects with pathological values of IMP than for those with IMP values in the normal range. Total changes in IMP and EMG amplitude during 1 min isometric contraction were linearly interrelated (r = 0.747, p < 0.0001). We conclude that both surface electromyography and myotonometry parameters are indicative of intramuscular pressure, but neither of these methods can be used alone to diagnose non-invasively chronic compartment syndrome with acceptable accuracy.

An investigation into the variability between different shear wave elastography systems in muscle

“…Muscle stretch and contraction elastic elements are major determinants of muscle function and efficient locomotion [4,5]. The measurement of these parameters has largely been explored using myotonometry but this has not been shown to have acceptable accuracy and is limited to superficial muscles only [6,7]. Additional techniques such as magnetic resonance elastography (MRE) and standard ultrasonography can assess the mechanical properties of tissues in-vivo.…”

Feasibility of monitoring muscle health in microgravity environments using Myoton technology

“…However, MAS results lack objective grading and reliability [5,16] and are not well correlated with muscle stiffness after stroke [3]. To meet this need, a novel approach, myometric measurement, has been introduced showing reliable [2,4,15], objective and user independent measurements [1, 10,22] for healthy adults [8] as well as for various patient populations, including Parkinson's disease [13,21] and stroke [6] patients. As well as being used to evaluate the tone and biomechanical properties of muscles and tendons (e.g.…”

“…As well as being used to evaluate the tone and biomechanical properties of muscles and tendons (e.g. frequency, stiffness and elasticity), myometric measurements have also shown an almost linear relationship with electromyographic (EMG) activity and therefore provide an indirect measure of changes in the muscle force generating capacity [4,10].…”

Muscular hypertonicity: a suspected contributor to rheumatological manifestations observed in ambulatory practice

“…More definitive future studies can include developing instrumentation facilities to measure the muscle's passive properties of stiffness, tension, and viscoelasticity (35,36) as well as monitor active contractions with surface EMG (14,37).…”

“…Exaggerated stretch reflexes could result from trigger points or neurological causes (1-3, 11); however, these factors are not believed to have operated meaningfully in the described assessments or the comparative results. Future studies of MHT may incorporate quantitative measures of stiffness or pressure compliance using myotonometry (4,37), and their accuracy can be further enhanced with the use of EMG monitoring (14). Consistency in clinical measures of resting muscle stiffness and tightness requires patients to relax to maximal degree in comfortable, balanced postures (13,38).…”