Why should the Physical Medicine Practitioner be interested in sEMG?

Many physical medicine practitioners work with soft tissue problems while traditional methods of assessing pain related problems, such as radiographic techniques, needle EMG studies and Nerve Conduction Velocity studies are well suitable for bone and nerve related problems, they are insensitive to muscle, tendon, ligament and articular dysfunction. And traditional methods for assessing soft tissue pain related problems, such as palpation, are ultimately subjective.

Surface EMG technology specifically monitors muscle action potentials (MAPs), and this is known to be sensitive to soft tissue injuries. For example, in some cases of dysfunction among homologous muscle pairs (or between agonist and its antagonist or synergist) there is an imbalance in relative stiffness in the muscles that participate in a specific movement.

Such imbalances are thought to be due to faulty central nervous system motor control problems, along with peripheral factors such as inefficient length-tension relationships and passive myofascial compliance. When the practitioner puts the sEMG findings together with clinical examination (from evidence of segmental and supra segmental motor reflexes, sympathetically mediated reflexes, instabilities, articular and periarticular factors, nutritional factors, beliefs, attitudes and affect of the patient) the relationship between muscle impairment and other physical and psychological factors becomes clearer.

Correct classification of impairment with observed functional limitations may be used to derive treatment planning in a thoughtful way. Surface EMG techniques and associated feedback displays can make treating the patient more efficient. For example, sEMG can help identify inappropriate muscle substitution patterns and thus refine therapeutic exercise prescription. Motor copy templates can be used to assist in [earning new recruitment patterns. sEMG triggered electrical stimulation has been shown in some studies to facilitate the rehabilitation process.

Lastly, sEMG monitoring provides an objective documentation trail of the impact of the physical therapy on muscle function, thus allowing the therapist to demonstrate gains both to the patient and third party payer.

Can sEMG he useful in Therapeutic Exercise prescription? In physical medicine, it Is extremely important that the patient practice stretching and strengthening exercises on a periodic basis. Today, it is very common to teach a patient a set of exercises and give them a handout to remind them of what they are to do until the next visit.

What sEMG monitoring of an exercise prescription does is guarantee that the exercises are activating the desired and targeted muscle group(s). sEMG monitoring better assesses the patient's actual ability to activate the desired muscle, without muscle substitutions or co-contractions. If necessary, the therapist can refine the home exercise instructions for the patient to make it more effective.

Does sEMG monitoring have a role to play in postural assessment or training?

Posture is an important part of physical medicine. If the posture is bad, movement may be compromised or muscle substitutions may appear.

sEMG monitoring allows the therapist to better quantify the muscular efforts dictated by posture. A head forward position in a patient with cervical pain will, in all probability, show elevations in the cervical paraspinal muscle activity. If this is the case, one could argue that the cervical pain is potentially maintained either by the weight of the head placing an undue strain on the periarticular structures or by the build up of lactic acid associated with muscular efforts required by the posture.

While the therapist can instruct the patient in how to move their head back into better postural alignment, it is much better to show the patient how the muscles at the back of the head can relax with a postural correction.

Many a patient of mine has finally caught onto the necessity of postural correction based upon what the sEMG has taught them."

Can stretching be assisted by sEMG monitoring?

Stretching is more effective if the muscle relaxes during the stretch. The problem is that when muscle tissue is stretched, the stretch receptor gets stimulated causing the muscle to become active.

sEMG monitoring during stretching can be used to assist the patient in relaxing the muscle during the stretch. This is because the muscle spindle is, in part, under voluntary control. By learning to breathe into the stretch and to relax into the stretch, the soft tissue has a better chance of actually elongating. The sEMG signal can be used to guide the patient, quieting the muscle being stretched. This could accelerate the rehabilitation process.

What about NMES (Neuromuscular Electrical Stimulation) capabilities of Bioconnect?

Bioconnect has built into it a threshold function. The therapist can set the threshold, and choose "NMES" as the consequence of meeting the threshold. The Bioconnect software will turn on the switch at the PRO SB interface which plugs into the back of the computer. From this switch you can run a cable to an approved e-stim device. Once the switch is turned on by the patient's effort, it remains on for the duration of the work trial. At the end of the work trial, the switch is turned off.

NMES protocols may be used for retaining the neurologically involved patient. such as stroke. This procedure has been demonstrated to assist the patient in appropriately strengthening the desired muscle group, while increasing their proprioceptive awareness of that muscle (See Chapter 6 in Kasman, et a[). This accelerates the learning process. In today's physical medicine world, this is extremely important.

What are some of the features of the software which make the practitioner's life easier? There are a number of pre-programmed clinical protocols supplied with the software for the assessment and treatment of

a variety of problem areas. These assist the practitioner by providing a relevant number of channels to monitor, along with applying meaningful muscle and movement labels to the sEMG screens.

The Bioconnect software also carries some very nice Work Rest treatment protocols. Here, the program provides labels on the screen for the desired activity, and the practitioner may turn on a count down clock to guide the patient's activity. The clock changes colors as the different activities are done. Statistics are also available to describe each of the activities.

A template option is available to assist the practitioner in creating and using motor copy protocols. For the *self directed" practitioner, placing the correct muscle labels on the patient's screen is very important. Bioconnect allows the placing of new muscle labels by simply clicking on the current muscle label. With this click, a drop down menu of possible labels is presented. One simply scrolls through the list, and chooses the muscle of choice. This [abet with the right and left designators is then placed next to the graph.

Movement captions (such as Rexion, extension, etc) to label the contents of the screen may be easily placed at the bottom of the screen. The practitioner can type in a description or select a movement from a drop down menu.

Tell me more about the templates option?

In neuromuscular rehabilitation, the use of motor copy templates can accelerate the [earning process. in stroke rehabilitation, one motor copy strategy is to ask the patient to make the desired movement with the "good" side, and then use that "template" to help guide and shape the relearning of the deficient side. This template is placed on the feedback or treatment screen, and the patient tries to copy the template using their own muscle efforts.

While the Bloconnect software comes with a few sample templates to choose from, it allows the therapist to develop their own library of templates.

In what ways does Bloconnect display the sEMG data?

Bioconnect presents real time sEMG displays. Here the practitioner can select a pre-programmed sEMG display or use the 'on the fly' approach. With the latter method, the therapist may easily select the desired number of sEMG channels, set the color and width of each sEMG line, apply the appropriate muscle and movement labels, and begin monitoring the sEMG.

Once data has been collected, it can be reviewed in the following ways: Statistical review at the end of a particular screen or both graphic and statistical review of each trial at the end of a session.

The statistical review of each trial provides the Mean, Minimum, Maximum, Standard Deviation, and % asymmetry between the right and left sides of homologous pairs. These statistics are available for each trial. For example, if the screen had a rest, work and rest trial on it, there would be statistics associated with the event. In this way, you could survey the beginning rest values, the maximum during work, along with how well the muscles recovered following the effort.

Does Bioconnect take advantage of the "multi-media" potential of a Windows environment? This is one area where Bioconnect separates itself from other sEMG software. Bioconnect fully utilizes the HTML and " Direct X" features of Windows-. In some of the pre-programmed protocols, still photographs are utilized to show where to place electrodes or in what ways you would want to have the patient move. This information is presented in a context sensitive fashion. In some of the more advanced protocols, video clips are played to demonstrate to the patient (and therapist) the type of movement to be assessed or trained.

Part of the goal of the software is to provide the practitioner with a set of standardized assessment and treatment protocols so that the assessment they conduct is similar to those conducted by others. In this way, the practitioner can begin to compare their findings with those of others in the field.

Surface EMG monitoring relies on effective electromyographic hardware and software.

What can you say about the Thought Technology products and Bioconnect software?

The sEMG hardware developed by Thought Technology has many salient features. First of all, it utilizes a low noise, high impedance SEMIS preamplifier at or near the electrode site. This dramatically reduces the possibility of extraneous environmental noise contaminating the sEMG signal. It also allows for two filter bandwidth selections, so that the practitioner can choose to eliminate the ECG artifact (the 100-200 Hz fitter) or record from the entire sEMG spectrum (the 20-200 Hz filter). Lastly, the fiber optic cable that connects the hardware to the computer provides the ultimate in electrical isolation and patient safety.

The Bioconnect software provides the graphic user interface that the practitioner uses to record and display the sEMG signal. This software has been specifically designed by clinicians for the physical medicine practitioner.

So, overall, what do you like about the Procomp+/ Bioconnect System?

The key attribute of the Bioconnect software is that it is a Windows' software specifically designed for sEMG monitoring. This means that the displays, the control features, and its look and feel were designed with the physical medicine practitioner in mind.

The Bioconnect software is the first software for Procomp Plus which allows you to read up to eight channels of muscle activity. While two to four channels of sEMG are ideal for training and re-education purposes, an 8 channel display allows you to better assess neuromuscular function by letting the practitioner see four sets of homologous pairs simultaneously.

From an assessment point of view, the software allows you to do an "on the fly" assessment, pacing the patient through your favorite moves. And, the software comes with a set of pre-programmed clinical protocols that provide the practitioner with easy to use assessments for the neck, shoulder and low back. In addition, it allows for the purchase of augmented evaluation perspectives using "plug ins" from practitioners such as myself, Gabe Sella, MD, Barbara Headley, PT, and others.

The controls of the sEMG signal are superbly simple. Start, Stop and Clear screen can be done by a click of the mouse or using one of the F keys. You can easily make comments about a patient's tracing either at the time of the movement or during a later review. These will be printed at the time of report generation.

Audio feedback, threshold, and movement templates are allowed to facilitate neuromuscular re-education. Work - Rest cycles are pre-programmed to allow easy access to common training procedures.

The sEMG data is stored and easily retrieved and reviewed. We believe the job isn't done until the paperwork is through. And Bioconnect allows for a variety of report formats.

The bottom line is that the Procomp Plus Bioconnect system is very easy to use, greatly facilitates the rehabilitation process, and provides objective information about the process.

Cram J.R and Birtman 8. Surface Electromyography: An Electrophysiological Alternative in Pain Management. In Welner R (ed), Pain Management: A Practical Guide For Clinicians. St Lucie Press, Boca Raton. R, 81-96 1998.

Kasman G, Cram JR, Wolf, 5 and Barton, L. Clinical Applications In Surface EMG: Aspen Publications, 1997.

Jetti AM. Physical disablement concepts for physical therapy research and practice. Physical Therapy, 1994, 74:380-386.

Cram J.R. Clinical EMG For Surface Recordings (Volume 2). Clinical Resources, Nevada City. CA 1990.

Wolf 51, LeCraw D and Barton L. Comparison of motor copy and targeted biofeedback training techniques for restitution of upper extremity function among patients with neurologic disorders. Phys Ther. 1989; 69:719-735.

Cram JR, Kasman G. and Holtz J. Introduction to Surface EMG. Aspen Publications, 1997.

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