Today, there is an innovative muscle diagnostic technique that is simple, fast and non invasive and can add accurate objective muscle measurements to the often difficult diagnostic process.
Musculoskeletal diagnosis is frequently made on the basis of patient history and physical examination sometimes complemented with imaging (US, MRI…).
Tensiomyography (TMG) is method for measuring biomechanical properties of skeletal muscle. It is an objective accurate and non-invasive process used to measure and monitor radial muscle belly displacement under isometric conditions.
Radial muscle belly displacement is of major importance since changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force. Thus, lattice spacing is a significant force regulator, increasing the slope of a muscle’s force–length dependence.
Musculoskeletal disorders (MSD) are one of the biggest contributors to activity “time out” whether the activity be sport, work or leisure. The cost of musculoskeletal disorders can reach 3, 4% of gross domestic product and in the UK alone 11.6 million working days a year are lost to MSD. The key question concerning MSD is, do we have enough relevant information about skeletal muscles, to be able to better diagnose and manage MSD? The aim of these application notes is to highlight Tensiomyography as an eminently suitable diagnostic aid that can be used in order to ascertain individual’s critical data in order to facilitate treatment of or with preventive treatment, avoid MSD.
Changing of activation pattern of the muscle contraction(detected on TMG signal) can be important element for early diagnostic of MSD. since information on muscle fiber type and composition is of great importance in muscle physiology.
A displacement sensor is positioned perpendicularly to the tangential plane on the largest area above the muscle belly. The muscle belly displacement (enlargement) during contraction is measured and recorded. Muscle contraction is elicited by single-twitch electrical stimulus. Two self-adhesive electrodes are placed symmetrically to the TMG sensor. The anode is placed distally and the cathode proximally, 20-50 mm from the measuring point. Bipolar ES consisted of a single DC pulse of 1 ms in duration.
The measured parameters are the maximal amplitude of the signal (Dm), the delay time from the stimulation to 10% of the maximal contraction (td), the time of contraction from 10% to 90% of the maximal contraction (tc), the time of sustained contraction from 50% contraction to 50% of the relaxation (ts) and the relaxation time from 10% relaxation to 50% relaxation (tr).
Tensiomyography has been utilized to monitor pre and post-operative muscle adaptation during the process of ACL reconstruction and rehabilitation. The results demonstrated different patterns of adaptation for each of the skeletal muscles used to ensure knee joint stability. It is very important to have selective information about skeletal muscles when evaluating MSD, since it is necessary to understand the alteration of skeletal muscle contraction pattern due to pain. It is proposed that motor control changes in patients are functional in that they enhance muscle stability.
With Tensiomyography critical information can be obtained through a non-invasive method, without any effort on the part of the subject. It enables optimization of rehabilitation through precise definition of appropriate load and intensity of work, or to detect local muscle fatigue as a changed ability to activate muscle fibers. Moreover, the muscle properties can be controlled to detect any change in the muscle due to a recent injury or an inadequate amount of work, demonstrated as local muscle fatigue. (For example the level of muscle strain can be detected during a very short procedure. )This information can be of great value in managing postoperative recovery or rehabilitation medicine.
To conclude, Tensiomyography is a non-invasive, selective, functional, muscle diagnostic method that has very high repeatability. Tensiomyography can provide accurate objective muscle measurements to the often difficult diagnostic process. Furthermore Tensiomyography can contribute to the optimization of rehabilitation and physical recovery of patients/athletes.