My biography

Hello. My name is David,

I am a husband, friend, father of two and a grandfather of seven. I earned a B.A. in Social Science and Economics at UC Irvine. I am an accomplished software developer who tested the prototype Voyager spacecraft in the 1960’s, and later programmed computers and managed software development for the healthcare and entertainment industries.

My life passions are computers, reading, electric trains, working as a soccer referee for 30 years, camping/ kayaking and my grandchildren. I helped an African orphanage and self-sustaining industries (fuel-efficient cook stoves and water well drilling),

                                               

On May 19, 2009, I was driving my car when I had a sudden headache.  I was able to follow another car through the intersection and stop my car by the curb.  I then called for help. My wife came to me and called the paramedics.  I had a stroke.  I underwent an embolectomy (surgery using TPA) about 5 hours later, to relieve the bleeding and treat large three blood clots. A week later I had a blood clot removed from behind my right knee.  I had a right-brain ischemic stroke, resulting in left-sided hemiplegia and some other related issues (mid-line imbalance, vision processing speed, focus and depth perception impacts, swallowing and memory issues).  .  I spent six weeks recovering in Northridge Acute Rehabilitation Hospital.

On October 5, 2010 I fainted while standing up due to a major drop in blood pressure, probably caused by prescription-medication, fell and broke my hip.  I’ve since had a hip replacement and additional inpatient and outpatient rehabilitation.

I’ve been actively pursuing therapies that would help me regain my body and mental functionality since May, 19, 2009.

“When I talk to other stroke survivors, I make sure they know there are new devices out there that might help them. Next, I tell them to never give up hope because you never know what is going to come out in the future. I know firsthand that it takes time to heal. I try not to focus on what I can’t do and I focus on what I can do. With the new technology that is being developed and the new drugs and therapies on the horizon, the way I am today is not how I am going to be in a few years.”

“I try everything that is out there with the philosophy that if it helps stimulate any part of my body, or my brain, then it is worth trying…”  “…I don’t ever want to look back and think about what we should have or could have done. You never know what will be developed tomorrow and how it might change your life.”

There is much more than robots, VR games, PTSD training and driving simulators that could be used to harness affected brain functionality for stroke rehabilitation. I believe that productive retraining of brain functionality will aid long-term stroke recovery-

I attend the California State University, Northridge Center of Achievement, Western Center for Aquatic-based Therapy, where I’ve improved my strength, endurance and balance.

After 8 months of work with computer-assisted brain function and vision processing programs, I recovered my driving privileges.

As a Consultant/Project Manager for the CSUN Student Affairs IT Group, I documented the Student Affairs IT PMM (Project Management Methodology) for IT Services Software Development, and developed a new web project acceptance testing plan and User Reference Manual for the CSUN Tours Registration/Scheduling group.  I also developed tutorials in Excel and PowerPoint for students.

After months of traditional inpatient and outpatient rehabilitation, plus aquatic therapy, I participated in six weeks of occupational therapy robotic training at Rancho Los Amigos. I used the Interactive Motion Shoulder and Arm Robot twice a week for one hour each session totaling thirteen sessions.

The functional changes I have gained after using the InMotion Robot are:

• I am able to now use my left arm to hold my granddaughter on my lap to read to her.
• I have increased the use of my left side. I turn light switches on and off; I rest my left hand on the shower wall while my eyes are closed; I am able to hug people with both arms; I carry objects under my left armpit; I am more balanced , and have greater endurance, when I walk.  I’ve gained significant range of motion, and reduced spasticity and pain.
• After the first robotic session, I was able to lift my left foot up to my buttock (for the very first time).

(The key is that stimulating one part of the brain affects many other parts also.)

• After a three-month hiatus from the robot, my recent session (7/6/2011)  was my best functional performance ever.

The functional changes I have gained after using the MYOMO Robot are:

• Greater sensitivity and tactile feeling in my left hand.
• Strengthening of my Tricep and inhibitory control of Bicep/Tricep to raise and lower my left arm.

I have recently gained greater strength and arm mobility such that I am able to move my left arm more to dress myself.

In October, 2011 [30-months post-stroke] I began to have limited, volitional, movement of my left thumb.

I am a mentor/volunteer in the Rancho Los Amigos Robotic Therapy program, assisting therapists and patients in using robotic therapy tools.

As a volunteer in the Rancho Los Amigos Rehabilitation Engineering Lab as a research subject for the projects designed to improve impaired- and handicapped-persons lives  (including development of improved Virtual Reality tools and games, and enhanced mobility projects), and entering data for research projects. 

Also at Rancho, I assisted in the “Introduction to Computers” computer skills lab, and  in the Drivers Training Program, as well as participating in the development of Stroke/TBI Wellness Programs.

 I continue my active support for the US Soccer Federation as a referee-instructor, and assignor, helping to train new and improve experienced soccer referees.

I’m a patient/volunteer for the CSUN Physical Therapy graduate students and for the USC Neuro Consortium for the Neurologic Examination Toolbox Course to provide direct experience with patients' evaluation and post-stroke treatment, and for the Neurorehabilitation Laboratory, Division of Biokinesiology and Physical Therapy at the School of Dentistry Interaction Lab, Department of Computer Science, USC Viterbi School of Engineering for the USC  Motor Sensor Study and Virtual Reality for Rehabilitation development.

I am also involved in the USC OPTT-RERC (Optimizing Participation Through Technology) - Rehabilitation Engineering Research Center for Technologies for Successful Aging with Disability) Programs, including development of Virtual Reality software for rehabilitation, using the Microsoft Kinect camera as a monitoring/input device, in a design that will give the user feedback on their progress in a simple, condensed manner [the game system would be programmed to automatically make adjustments in task difficulty as the user improves (and, the clinician would still be given the ability to override the game's algorithms if they deem it necessary).   The final major feature to be included is access to an online social network for system users, so that users can easily chat with one another to provide encouragement, play the games together, have friendly competitions to see who can stick with their rehab regimen the best, etc.

I was a patient/volunteer for the USC research project doing brain mapping research with TMS (transcranial magnetic stimulation).  This study is investigating the way that the brain learns new skills.

I tutor high school students in physics, computer uses, Excel and PowerPoint, and started to tutor a three and one-half [3 ½] year-old learning to read.

In September, 2010 I was selected as an at large member for the State of California SSFL Public Participation Group, applying my research and analysis skills to review the Toxic Cleanup Project analysis, results and plans for the Santa Susana Field Laboratory (a toxic ground and groundwater site affecting the San Fernando and Simi Valleys).

I participate on the Northridge Hospital Patient Advisory Council helping to improve patient support in the Acute Rehabilitation Unit. 

Recently, I started as a volunteer in the Northridge Hospital PT/OT Department performing research and office administrative functions to support the professional and  administrative staff.

In 2011 and 2012 I received Botox treatment for left arm and hand spasticity, and plan to continue my traditional therapies and robotic therapies.

In September, 2011, I began using a MYOMO worn-on-the-arm robot to improve brain neuron to arm muscle control to re-establish lost Upper Extremity functionality

I’ve begun as a member of the Division of Biokinesiology and Physical Therapy at the Herman Ostrow School of Dentistry, University of Southern California  Board of Councilors, to support and guide the program.

As a participant in Virtual Reality Software  development at USC ICT and Rancho Los Amigos, In February, 2012 [33-months post-stroke] I used my left hand to work a VR software game. 

At Rancho Los Amigos and Northridge Hospital, I am actively working on expanding medical professionals’ and the public's knowledge about stroke prevention, post stroke acute treatment and long-term support for stroke patients to recover a high quality of life through new “wellness” programs.

I still have my dream of kayaking through the Grand Canyon – after I complete more rehabilitation, and gain strength and muscle control in my left side.

Soon, I hope to begin attending classes leading to a certification or degree in Applied Robotics, Game Theory, VR Application Design and Development,  or Assistive Technology Program

NOTES REGARDING ROBOTICS:

The Interactive Motion Robot System was developed at Massachusetts Institute of Technology with medical experts from Harvard Medical School. The developers intended for the device to benefit stroke survivors suffering from severe muscle weakness or hemiparesis, which is weakness resulting in complete or partial loss of movement on one side of the body.

This evidence- based system is unique in the industry and has been tested by leading medical centers worldwide for 10 years in over 40 studies with over 400 patients.  The InMotion Robot's exceptional capacity for measurement and immediate interactive response sets it apart from other types of therapy systems.

Technology:  The InMotion Robot's immediate interactive response assesses the patient's UE movement and responds to the patient's continually-changing ability.  Like an experienced clinician the robot then guides the exercise treatment accordingly:

          -----------------------------------------------------------

The Myomo Robot System is an intelligent robotic device, paired with a specific evidence-based therapy regimen through which patients learn how to self start and control movement of limbs that are weak or stiff. The movement is initiated in the person’s brain, where a natural signal is sent from the brain to the muscle communicating the command. This signal then moves down the body to the arm, initiating a weak muscle contraction, too weak to cause the arm to move on its own. The computer in the robot then picks up this signal and magnifies it, much like turning up the volume dial on the radio, helping the person complete the movement.

Through repetition the person may eventually relearn how to move and control the affected muscles. It can help improve the quality of life for survivors by allowing them to perform real-life tasks such as pushing to stand, eating a piece of fruit or reaching for a light switch or lifting a box. The tasks are progressed from simple to more complex under the guidance of a certified licensed physical or occupational therapist.

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VIRTUAL REALITY

Virtual reality (VR) is a term that applies to computer-simulated environments that can simulate physical presence in places in the real world, as well as in imaginary worlds. Most current virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones. Some advanced, haptic systems now include tactile information, generally known as force feedback, in  these applications.

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Understanding Spasticity vs Order of Recruitment

Dr.[Beth Fisher, PhD, PT, Associate Professor of Clinical Physical Therapy , USC Division of Biokinesiology and Physical Therapy ] had her students read the attached article which shows that it is not necessary to decrease spasticity in order to improve the ability to move the upper extremity following a stroke.  Many medical doctors and  therapists assume that SPASTICITY is the main problem that must be remediated, whereas in actuality it is a weakness/compensatory movement issue. The individual post stroke must be trained to re-learn how to use the affected side by minimizing compensatory movements (ex: using the trunk to move instead of moving just the arm), strengthening the weak muscles (spastic muscles are pretty much always weak) and working in a functional context  (ex: practicing reaching/loading tasks) instead of just trying to "decrease spasticity". Decreasing spasticity alone won't help movement unless it is tied into practice of the specific task that one is trying to improve.



Overcoming Limitations in Elbow Movement in the Presence of Antagonist Hyperactivity

                 CLICK HERE TO FIND ONLINE 



TThe online version of this article, along with updated information and services, can be found in in the following collection(s):

Therapeutic Exercise
Stroke (Neurology)
Stroke (Geriatrics)

Kinesiology/Biomechanics

Definition of Spasticity

Spasticity: A state of increased tone of a muscle (and an increase in the deep tendon reflexes) when there is a sudden muscle movement.  For example, with spasticity of the legs (spastic paraplegia) there is an increase in tone of the leg muscles so they feel tight and rigid and the knee jerk reflex is exaggerated, when the leg is suddenly moved.

Order of Recruitment
As a general rule, motor units are recruited in order of their size. When the muscle is activated initially, the first motor units to fire are small in size and weak in the degree of tension they can generate. Starting with the smallest motor units, progressively larger units are recruited with increasing strength of muscle contraction. The result is an orderly addition of sequentially larger and stronger motor units resulting in a smooth increase in muscle strength.^[2]

This orderly recruitment of sequentially larger motor units is referred to as the "Henneman size principle", or simply "size principle."^{[2, 3, 4]} Recording from the ventral rootlets in cats and measuring the amplitudes of motor axon spikes, Henneman et al concluded that motor axon diameter, conduction velocity and, by further inference, motor neuron cell size all increase with functional threshold.^[2]

There are exceptions to the size-ordered activation of motor units. Motor unit recruitment patterns vary for different movement tasks, depending on many factors, including the mechanical function of the muscle, sensory feedback, and central control.^[3] After nerve injury, the relationship between motoneuron size and the number and size of muscle fibers that the motoneuron reinnervates is initially lost.^[4] With time, however, a size-dependent branching of axons accounts for the rematching of motor neuron size and muscle unit size, and the size-ordered organization of motor units properties is restored.^[4]

The 3 main types of motor units, which have different physiologic and staining properties, include the following:

·        Type I or type S (slow) - Slow twitch, fatigue-resistant units with smallest force or twitch tension and slowest contraction; contain oxidative enzymes

·        Type IIa or type FR (fast, resistant) - Fast twitch, fatigue-resistant units with larger forces and faster contraction times; contain oxidative and glycolytic enzymes

·        Type IIb or type FF (fast, fatigable) - Fast twitch, easily fatigable units with largest force and fastest contraction; contain glycolytic enzymes

 The recruitment sequence is thought to begin with type I motor units analogous to type S units, 
  to progress to type II units that first include type FR (type IIa), and to end with units analogous to 
  type FF (type IIb), which are active only at relatively high force output.

          RECRUITMENT

The needle EMG examination cannot assess anatomic size or degree of tension of a motor unit. In an EMG study, the term "size" of a motor unit usually refers to the amplitude of the motor unit action potential (MUAP). The size principle is also true to a limited extent for the EMG study. In rather general terms, the later recruited type II fibers, especially the FF type, have larger diameter muscle fibers generating higher potentials than the smaller, slow twitch type I units. Because of the small uptake area of standard EMG needle electrodes, however, the size of consecutively recruited MUAPs during an EMG study varies considerably.^[5]

Definition of Motor Unit Recruitment and Overview

Motor unit recruitment may be defined as "the successive activation of the same and additional motor units with increasing strength of voluntary muscle contraction."^[1]

The central nervous system can increase the strength of muscle contraction by the following:

·        Increasing the number of active motor units (ie, spatial recruitment)

·        Increasing the firing rate (firing frequency) at which individual motor units fire to optimize the summated tension generated (ie, temporal recruitment)

Both mechanisms occur concurrently. The primary mechanism at lower levels of muscle contraction strength is the addition of more motor units, but the firing rate of the initially recruited motor units also increases. When nearly all motor units are recruited, increase in firing frequency becomes the predominating mechanism to increase motor strength. At this level and beyond, motor units may be driven to fire in their secondary range to rates greater than 50 Hz.

The next section of this article discusses the physiology of motor unit recruitment in detail. Subsequent sections look at ways of examining recruitment during an electromyography (EMG) study. Assessment is made at different levels of innervation—minimal muscle contraction to determine the onset and recruitment firing rates (ie, recruitment pattern); maximal voluntary contraction to provide information about the interference pattern; and moderate voluntary contraction at various levels for assessment of the turns/amplitude analysis.

Assessment of Recruitment at Low Level of Muscle Contraction

An essential part of an EMG study is the assessment of motor unit recruitment at low levels of muscle contraction. The goal is to identify the recruitment pattern by measuring the firing rate of the first few recruited MUAPs.Normal recruitment pattern. (A) With minimal effort of muscle contraction, a single motor unit is seen firing at 6 Hz. The time between 2 discharges is approximately 166 milliseconds (ms), corresponding to a firing rate of 6 Hz (ie, the reciprocal). (B) Gradual increase in muscle strength results in recruitment of a second motor unit. Recruitment frequency is defined as the firing frequency of the first motor unit when a second motor unit is recruited. In this example, it is 12 Hz, the reciprocal of the recruitment interval, which is 85 ms. (C) With further increase in muscle strength, a third motor unit is recruited.

As described in the previous section, the first recruited motor units arise from the small and relatively slow-conducting type I motor units exclusively. Recruitment analysis at low levels of muscle contraction, therefore, assesses type I motor units predominantly. Type II motor units are recruited later and are not analyzed in this way.

The patient is instructed to make only a very gentle contraction of the muscle under investigation. In the normal situation, the first motor unit usually begins to fire irregularly at 2-3 Hz and then achieves a stable and fairly regular firing rate at 5-7 Hz. This is the "onset frequency." When the patient minimally increases the force of contraction, the first unit increases the rate of firing to 6-10 Hz. With further increase of muscle contraction, the second unit is recruited once the first unit achieves a firing rate of about 10 Hz.

Recruitment frequency is the firing frequency of the first motor unit when the second unit just begins to fire regularly. The term "recruitment rate" is used interchangeably.

Recruitment interval is the time difference between 2 motor unit potentials belonging to the first firing motor unit when the second unit first appears. The recruitment interval is the reciprocal of the recruitment frequency.

In practice (see image below), the patient is instructed to make only a minimal contraction of the target muscle, often by using a phrase such as "...just think about contracting the muscle..." Just 1 motor unit firing regularly should be identified (ie, MUAP A). The patient then is asked to very gradually increase the force of muscle contraction. MUAP A then may increase its firing frequency and at one point a second motor unit (MUAP B) appears. This event can be recognized by observing the screen and by listening for a change in sound associated with firing of 2 motor units. Once this event is recognized, the examiner should "freeze" the screen. The time difference between 2 sequential potentials of MUAP A is the recruitment interval.

Normal recruitment pattern. (A) With minimal effort of muscle contraction, a single motor unit is seen firing at 6 Hz. The time between 2 discharges is approximately 166 milliseconds (ms), corresponding to a firing rate of 6 Hz (ie, the reciprocal). (B) Gradual increase in muscle strength results in recruitment of a second motor unit. Recruitment frequency is defined as the firing frequency of the first motor unit when a second motor unit is recruited. In this example, it is 12 Hz, the reciprocal of the recruitment interval, which is 85 ms. (C) With further increase in muscle strength, a third motor unit is recruited.

The recruitment interval may be measured by placing 2 time markers on the 2 sequential MUAPs A. The recruitment frequency may be calculated as the reciprocal of the measured recruitment interval. This is a precise but cumbersome way of determining the recruitment frequency; in practice, most examiners use an estimate of the recruitment frequency instead.

A fast estimate of the firing rate of MUAPs is obtained by looking at the screen of the EMG machine. Assuming that the sweep speed is 10 milliseconds (ms)/cm, and the monitor of a typical EMG machine has 10 cm (10 divisions) across the entire screen, therefore, one screen represents 100 ms. A MUAP firing at 10 Hz means that it is firing 10x per 1000 ms, equivalent to 1x per 100 ms. It appears, therefore, once on the screen. As long as the sweep speed is 10 ms/cm and the screen is 10 cm across the screen, simply multiplying the number of times the MUAP is present on the screen by 10 yields an estimate of the firing frequency. A MUAP firing twice per screen, therefore, has a firing frequency of 20 Hz; if the unit is seen only once per screen but successively closer to the beginning of the trace with each new sweep, firing frequency is between 10 and 20 Hz.

Newer EMG equipment often has a 20-cm across the screen. At the same sweep speed of 10 ms/cm, therefore, the width of a single screen represents 200 ms (see images below). A MUAP firing at 10 Hz appears twice on the screen. A unit seen only once per screen is firing at 5 Hz, a unit seen 3 times is firing at 15 Hz, and so on. In this setting, therefore, the multiplication factor of 5 is used to arrive at an estimate of the firing frequency. The same multiplication factor is used for the 10-cm screen; if the sweep speed is increased to 20 ms/cm, it results in 200 ms across the entire screen.

Normal recruitment pattern. (A) With minimal effort of muscle contraction, a single motor unit is seen firing at 6 Hz. The time between 2 discharges is approximately 166 milliseconds (ms), corresponding to a firing rate of 6 Hz (ie, the reciprocal). (B) Gradual increase in muscle strength results in recruitment of a second motor unit. Recruitment frequency is defined as the firing frequency of the first motor unit when a second motor unit is recruited. In this example, it is 12 Hz, the reciprocal of the recruitment interval, which is 85 ms. (C) With further increase in muscle strength, a third motor unit is recruited.Decreased recruitment in neurogenic conditions. This single motor unit is firing at 15 Hz. The firing rate is calculated from the presence of 3 MUAPs on a screen of 200 milliseconds. This rapid firing unit indicates a neurogenic pathology; the underlying condition in this patient is amyotrophic lateral sclerosis.Early recruitment in myopathic conditions. In this electromyographic (EMG) study of a patient with inclusion body myositis, many motor units are activated simultaneously at a low level of muscle contraction. Note the low amplitude and short duration of individual units.Incomplete interference pattern. This example shows a discrete interference pattern in a patient with amyotrophic lateral sclerosis. Despite maximal voluntary effort, individual MUAPs can be identified and the baseline is partly visible.

Most extremity muscles have a recruitment interval of about 90-100 ms, corresponding to a recruitment frequency of about 10-11 Hz. Facial muscles are an exception to this rough guide. MUAPs of facial muscles have shorter recruitment intervals (around 40 ms) and higher recruitment frequencies (about 25 Hz).

In the example of an EMG screen set at 200 ms across the entire screen and recording from an extremity muscle, a single motor unit firing should not be seen more than twice. If the first recruited motor unit is seen 3 times or more before the second unit is activated, then this suggests an abnormality.

The orderly recruitment of successive motor units may be described as a rough approximation by the "rule of fives." Motor units begin firing at stable rates at 5 Hz. When the first unit to fire (MUAP A) reaches 10 Hz, the second motor unit (MUAP B) is activated and fires at 5 Hz. With further increase in muscle contraction force, MUAP A and B increase their firing frequencies, until MUAP A reaches about 15 Hz and MUAP B about 10 Hz. At this point, MUAP C is activated. Each time a motor unit is recruited, 5 Hz is serially added to the firing frequency of each MUAP already present.

The recruitment ratio is calculated from the firing frequency of the fastest firing MUAP divided by the number of different MUAPs on the screen. This ratio should be close to 5. In the example just discussed, MUAP C is activated when the firing frequency of the fastest firing MUAP (ie, MUAP A) is 15 Hz. The recruitment ratio is 5 (15/3).

If the recruitment ratio approaches 10, motor units are too few for the greatest firing frequency and force produced (ie, decreased recruitment). If it is reduced to less than 4 or 5, then motor units are too many for the highest firing rate (ie, early recruitment). Abnormal recruitment patterns such as these are discussed in the next sections.

Decreased Recruitment in Neurogenic Conditions

Damage may occur to the neural portion of a motor unit, anterior horn cell, or corresponding axon. Such injury may result in wallerian degeneration of the motor axon, and all the muscle fibers previously innervated by this axon will be denervated. As a result of such motor unit loss, fewer motor units are available for muscle activation.

Normally, when the first recruited motor unit reaches a firing frequency of 10 Hz, a second unit should begin firing with increasing muscular effort. In a neurogenic condition, this second unit is missing and an increase in force can be achieved only by increasing the firing rate of the first unit.

Decreased recruitment in neurogenic conditions. This single motor unit is firing at 15 Hz. The firing rate is calculated from the presence of 3 MUAPs on a screen of 200 milliseconds. This rapid firing unit indicates a neurogenic pathology; the underlying condition in this patient is amyotrophic lateral sclerosis.

Successful activation of a second motor unit occurs only at a higher level of muscular effort than in the normal condition. The recruitment frequency, defined above as the firing rate of the first motor unit at the point when the second motor unit is activated, is therefore increased in a neurogenic lesion. Such an abnormally fast firing motor unit is called "rapid firing unit" (RFU). Because in such cases fewer MUAPs are active than expected, given the first motor unit firing rate, this pattern is called "decreased recruitment" or "reduced recruitment."

This pattern of decreased recruitment may occur whenever a lesion results in a reduced number of functionally intact motor neurons and axons, whether it is the result of actual motor unit loss or temporary conduction block as in neurapraxia. It is an early finding after acute nerve injury (eg, radiculopathy from disk herniation or nerve trauma) and may precede other evidence of denervation in the EMG study.

Early Recruitment in Myogenic Conditions

In muscle diseases such as polymyositis or muscular dystrophies, muscle fibers are damaged. A number of motor units are unaffected but the muscle fiber content of each motor unit is reduced; therefore, the force output of each unit is diminished. The number of units required to maintain a given force increases in proportion to the inefficiency of the individual motor unit discharge. Compensation occurs by having multiple motor units begin firing simultaneously.

Early recruitment in myopathic conditions. In this electromyographic (EMG) study of a patient with inclusion body myositis, many motor units are activated simultaneously at a low level of muscle contraction. Note the low amplitude and short duration of individual units.

In a myopathy, isolating a single firing motor unit often is impossible. Even with minimal muscular effort, typically 2 or more units may be activated. This recruitment pattern in myopathic conditions is called "early recruitment" or "increased recruitment." The recruitment frequency is decreased.

Recruitment With Maximal Volitional Effort: Interference Pattern Analysis

With increasing effort, the firing frequency of individual motor units increases and progressively more and larger units are activated. In a healthy subject providing maximal voluntary effort of the muscle under investigation, the action potentials of individual motor units no longer can be separated from each other but are mixed with the signals of other units. The recruitment pattern with maximal voluntary contraction is called "interference pattern" because of the increasing degree of superimposition of action potentials from different units. With increasing force, the EMG becomes continuously denser and the maximal peaks in the signal have a higher amplitude.

American Association of Electrodiagnostic Medicine defines the interference pattern as "electric activity recorded from the muscle with a needle electrode during maximal voluntary effort."

During a maximal voluntary muscle contraction of a healthy individual, a "full" or "complete" interference pattern is present. No individual MUAPs can be identified clearly (this is normal). The baseline is obscured completely by motor unit activity.

Incomplete interference pattern may be divided as follows:

·        Reduced interference pattern (ie, intermediate interference pattern): Some of the individual MUAPs may be identified, while other individual MUAPs cannot be identified because of overlap.

·        Discrete activity: Each of several different MUAPs can be identified.Incomplete interference pattern. This example shows a discrete interference pattern in a patient with amyotrophic lateral sclerosis. Despite maximal voluntary effort, individual MUAPs can be identified and the baseline is partly visible.

·        Single unit pattern: A single motor unit fires at rapid rate during maximum voluntary effort.

An incomplete interference pattern typically signifies a decreased number of MUAPs being activated with maximal effort. This may be suggestive of a neurogenic lesion resulting in a decreased number of functional motor units. It may, however, occur with incomplete effort of muscle contraction, possibly as a result of poor cooperation or pain. In myopathic conditions, the interference pattern is typically complete, even though low-amplitude MUAPs may be noted on the recording of the interference pattern; however, in very advanced stages of muscle disorders, the interference pattern may be incomplete because of marked loss of muscle fibers.

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Tools, Games and Resources for Rehabilitation

Check these websites for Games and exercises that stimulate and focus your mind:
                          Games 4 Rehab
                       PositScience - The Human Brain
                       PositScience - Test Your Brain
                       Anti-Aging Games [memory improvement]
   
Look at Rancho Los Amigos Rehabilitation Robotic programs:
                         Rancho Los Amigos National Rehabilitation Center
                         Rancho Robotics

Additional Resources

See:  17.  Southern California Support Groups for Brain Injury +.

Living with a disability!

  Kermit

   Patience

Where can I learn more about stroke?

Always talk with your doctor or other health provider with any questions you have about your medical conditions.

Here are some important and useful resources about stroke.

American Heart Association/American Stroke Association (AHA/ASA):

•       http://www.heart.org/
•       http://www.strokeassociation.org/

National Institute of Neurologic Disorders and Stroke (NINDS):

•       http://stroke.nih.gov/

National Stroke Association (NSA):

•       http://www.stroke.org/

                         http://www.apta.org/
                         http://www.moveforwardpt.com/Default.aspx
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USC ICT’s Medical Virtual Reality Lab.

VIRTUAL REALITY

USC Institute For Creative Technologies      

                          http://ict.usc.edu/background

          http://in.reuters.com/video/2012/03/13/game-therapy-a-powerful-tool-for-paralys?videoId=231646110&videoChannel=1004  

Optimizing Participation Through Technology For Successful Aging With Disability

                           OPTT-RERC [Rehabilitation Engineering Research Center]

                  
                           http://www.isi.edu/research/rerc

  ICT has made significant improvements to the game -
 At the beginning, it was difficult
> for me to play the game - the kinect wouldn't track my left arm [ now will track much simpler],
    and the focus objects are brighter [easier to see]. But over time, the changes that have been 
   made have enabled me to play the game and provide  more detailed feedback.
> Key features of the games that are important and stand out over other video
   games are the option to tailor the game to different people and the option
   to play different games depending on the goal of the player or their
   clinician. The tracking of performance and ability to show improvement over
   time is also very helpful..

In February, 2012 [33-months post-stroke] I used my left arm/hand to work a VR software game for the first time.

NPR KINECT Story features Mark Bolas and Belinda Lange’s Jewel Mine Game

                         
/Posted by Orli Belman on July 18, 2011 in Games.

A story on NPR’s All Things Considered covered the many ways researchers and others are modifying the Microsoft Kinect. For the story reporter Alex Schmidt spoke to Mark Bolas, ICT’s associate director for mixed reality and an associate professor in the Interactive Media Division at the USC School of Cinematic Arts, about the trend.

“I remember getting this wrench with my father when I was 13 or 14 years old,” said Bolas. “And then with it, I could start working on my bicycle. And I got into motorcycles and all these things that I could build. The wrenches of today aren’t physical. They’re the software wrenches.”

Schmidt also visited a USC rehabilitation research clinic with Belinda Lange who leads the motor rehab group in ICT’s Medical Virtual Reality Lab. In the story Lange takes a patient through Jewel Mine, the Kinect-based motor rehab tool she developed, which gets a postive review from patient Stacey Holmes.

“It causes you to try things at a pace and a precision that you wouldn’t otherwise try to do,” he said.

 Listen to the story.

http://projects.ict.usc.edu/mxr/blog/npr-kinect-story-features-mark-bolas-and-belinda-lange%E2%80%99s-jewel-mine-game

CLICK ON  Listen to the story. IN THIS WEB PAGE

                                http://projects.ict.usc.edu/mxr/blog/npr-kinect-story-features-mark-bolas-and-belinda-lange%E2%80%99s-jewel-mine-game/

SOME ADDITIONAL LINKS TO CHECK INTO

                       MOTHER NATURE KINECT XBOX 360 DIANE TUCKER

                       http://kotaku.com/5816244/the-best-kinect-game-you-never-heard-of-and-maybe-the-best-of-them-all

EXPLORES THE USE OF KINECT IN EDUCATION - AS THE AUTHOR NOTED, THIS TYPE OF TECHNOLOGY HAS SO MUCH POTENTIAL IN LEARNING ENVIRONMENTS.

                    www.kinecteducation.com

                    
                   http://www.kinecteducation.com/blog/2011/11/15/what-is-kinecteducation-all-about/
                   

                    http://www.kinecthacks.com/kinect-swedish-dressing-room/

TOOLS TO ENABLE VR DEVELOPMENT

                         FAAST = FLEXIBLE ACTION AND ARTICULATED SKELETON TOOLKIT 

                         http://projects.ict.usc.edu/mxr/faast/

                         Evan A. Suma, Belinda Lange, Skip Rizzo, David Krum, and Mark Bolas

                         Project Email Address: faast@ict.usc.edu
                        http://mindshift.kqed.org/2011/07/with-microsoft-kinect-students-can-learn-how-to-hack/

                           http://www.isi.edu/research/rerc



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