This project was funded by, in part, by start-up funds from Wayne State University to M.H. Malek.

All procedures were approved by the University Institutional Review Board for Human Subjects.
1. Preparation of the Participant&#8217;s Leg
<ol>
	<li>Have the participant neatly roll up their shorts for the desired leg. Then tape the shorts so that the quadriceps femoris muscle group is exposed and draw a line around the area the participant needs to shave.</li>
	<li>IMPORTANT: Have the participant shave their leg before the test rather than the previous day as this ensures that there are no stubbles which may interfere with the EMG signal.</li>
	<li>Once the participant has finished shaving the desired area of the leg, clean the shaved area with rubbing alcohol to ensure there are no remnants of the shaving gel (or cream) which can interfere with the EMG signal.</li>
</ol>
2. Measurement of Leg for Electrode Placement
<ol>
	<li>In order to place the EMG electrode on the vastus lateralis muscle, make the following measurements
	<ol>
		<li>Have the participant stand straight facing the researcher.</li>
		<li>Locate the anterior spina iliaca superior (ASIS) and the lateral side of the patella. The ASIS is the hip bone; palpate it by placing the hand on either side of the abdomen below the umbilicus.</li>
		<li>With a tape measure, measure the distance between the two locations identified above and take 2/3 of that value on the line from the ASIS to the lateral side of the patella. Note: Further information regarding placement of EMG electrodes can be found on the SENIAM (Surface Electromyography for the Non-Invasive Assessment of Muscles) URL: http://www.seniam.org/</li>
	</ol>
	</li>
</ol>
3. Placement of the EMG Electrodes
<ol>
	<li>After the location of the vastus lateralis has been identified, take the EMG electrodes (most researchers use commercially available disposable Ag-Ag Cl electrodes) and place over the vastus lateralis without removing the adhesive shield. Then with a pen mark the area where the gel portion of the electrode makes contact with the muscle. Ensure that the interelectrode distance is 20 mm center-to-center.</li>
	<li>Use a piece of sandpaper (60 coarse) to gently abrade these two areas to remove the superficial layer of the skin. During this time, ask the participant their level of discomfort. Stop abrading when the participant indicates the area is warm.</li>
	<li>Clean the abraded areas with a towel that is dampened with rubbing alcohol or an alcohol swab. Allow the area on the leg to dry before placing the EMG electrodes.</li>
	<li>Place the EMG electrodes on the sites that were abraded (Figure 2). Take care not to place the electrodes on the iliotibial band (IT band). Ask the participant to contract the quadriceps femoris muscles in order to palpate the vastus lateralis. Place the electrodes on the muscle to ensure it is not on the IT band. Note: If the electrodes on the IT band, the EMG signal would be dampened when the participant is asked to maximally contract.</li>
	<li>Place the reference electrode (3rd electrode) on a boney attachment site such as the ASIS thus not interfering with movement of the lower limbs during the exercise bout.</li>
</ol>
4. Checking the EMG Signal
<ol>
	<li>Prior to starting the exercise test, check the interelectrode impedance. 
	Note: This step is critical because if the signal has too much noise then the EMG data collected during the exercise test will be invalid.
	<ol>
		<li>Have the participant sit in a chair and connect the EMG leads to their respective electrodes attached to the participant&#8217;s leg.</li>
		<li>At this point, have the participant relax their leg, having no tension in the muscle. Then after about 30 sec of relaxation, have the participant maximally contract their quadriceps femoris muscles for 5 sec and then go back to being completely relaxed.</li>
		<li>When performing the task above (step 4.1.2), record the participants EMG signal on the computer.</li>
		<li>Ensure that the interelectrode impedance is &#60;2,000 ohms. Moreover, if a voltmeter is available in the laboratory, then check the baseline noise and keep below 5 &#181;V. In addition, set the sampling frequency at 1,000 Hz.</li>
	</ol>
	</li>
</ol>
5. Setting-up the Cycle Ergometer
<ol>
	<li>After checking the interelectrode impedance, have the participant move from the chair to the cycle ergometer.</li>
	<li>Have the participant stand next to the cycle ergometer and raise their knee until the thigh is parallel with the ground. Then have the participant hold this position and adjust the seat height to match the same height as the participant&#8217;s thigh.</li>
	<li>Thereafter, have the participant sit on the cycle ergometer seat and then pedal a couple times while asking them if they are comfortable with the seat height. If needed, adjust the seat height.</li>
	<li>Ensure that the participant&#8217;s legs are near full extension with a slight bend (~5&#176;) in the knees during each pedal revolution.</li>
	<li>Before starting the test, have the participant wear a polar heart rate monitor so that heart rate can be documented throughout the exercise test.</li>
</ol>
6. Performing the EMG Fatigue Threshold Protocol
<ol>
	<li>Have the participant start cycling and gradually increase their cadence to 70 revolutions/min. Then increase the power output on the cycle ergometer to 50 W.</li>
	<li>Have the participant cycle at this power output for approximately 2-3 min. 
	Note: This is a low intensity exercise and will serve as the warm-up.</li>
	<li>After the warm-up period, increase the power output by 25 W every 2 min until the participant is no longer able to maintain the 70 revolutions/min cadence or requests that the test be stopped. 
	Note: It should be noted that during the exercise test, the EMG signal is recorded for 10 sec epochs during each 2 min stage for sec 10&#8211;20, 30&#8211;40, 50&#8211;60, 70&#8211;80, 90&#8211;100, and 110-12021. Most EMG systems will have an option to set the automatic recording at the desired interval. Thus, for each stage there should be 6 data files.</li>
	<li>Once the incremental test has concluded, have the participant perform a cool down at 50 W. Check that the length of the cool down corresponds with having the participant&#8217;s heart rate return to the value during the warm-up phase. Monitor this by checking the participant&#8217;s heart rate using the polar heart rate monitor.</li>
	<li>Once the cool down is completed, remove the EMG leads and have the participant step off the cycle ergometer and return to the chair. Then carefully remove the EMG electrodes and wipe the areas with a clean towel dampened with rubbing alcohol or an alcohol swab.</li>
</ol>
7. Processing the EMG Signal
<ol>
	<li>After the test is completed, process the raw EMG data files that were collected during the exercise test so that the data can be used to determine the EMG fatigue threshold.
	<ol>
		<li>Perform processing of the EMG signal with either the software used to collect the EMG signal or custom written software using various platforms such as MATLAB or LabVIEW.</li>
		<li>Filter the collected EMG signals using a band-pass filter. Use a setting of 10 to 500 Hz. Note: This alters the frequency of the signal so that low frequency artifacts due to movement of the EMG leads (&#60;10 Hz), and high frequency artifacts from the environment (&#62;500 Hz), are removed. Use a notch filter of 60 Hz if there is any interference from the power supply of the computer or EMG system.</li>
		<li>Once the signal has been filtered, determine the signal amplitude by calculating the root mean square value of the signal: Square each of the data points, sum them, divide by the number of data points, then take the square root of the resulting value. Perform these calculations using the aforementioned software.</li>
	</ol>
	</li>
</ol>
8. Determining the EMG Fatigue Threshold for Each Participant
<ol>
	<li>Perform the following steps for each participant.
	<ol>
		<li>After the EMG signal has been processed; use a statistical program (e.g.: GraphPad Prism) and label the first column &#8220;Time&#8221; and the subsequent columns with the power outputs used for the test.</li>
		<li>For each power output, fill-in the corresponding EMG amplitude value for each 20 sec interval.</li>
		<li>For each power output, analyze the time (x-axis) vs EMG amplitude (y-axis) relationship with linear regression to determine if the slope of the regression line is significantly (p &#60;0.05) different from zero.</li>
		<li>After performing the linear regression analyses for all power outputs, identify the highest power output with a non-significant (p &#62;0.05) slope.</li>
		<li>Then identify the lowest power output with a significant (p &#60;0.05) slope.</li>
		<li>Once these two power outputs have been identified, add them and divide by 2; the resultant power output is the estimated EMG fatigue threshold.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Hendrix, C. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+critical+force+to+EMG+fatigue+thresholds+during+isometric+leg+extension.">Comparison of critical force to EMG fatigue thresholds during isometric leg extension.</a> Medicine and science in sports and exercise. 41, 956-964 (2009).</li><li>Herda, T. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+the+effects+of+electrode+distance+from+the+innervation+zone+on+the+electromyographic+amplitude+versus+torque+relationships.">Quantifying the effects of electrode distance from the innervation zone on the electromyographic amplitude versus torque relationships.</a> Physiological measurement. 34, 315-324 (2013).</li><li>Ryan, E. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inter-individual+variability+among+the+mechanomyographic+and+electromyographic+amplitude+and+mean+power+frequency+responses+during+isometric+ramp+muscle+actions.">Inter-individual variability among the mechanomyographic and electromyographic amplitude and mean power frequency responses during isometric ramp muscle actions.</a> Electromyography and clinical neurophysiology. 47, 161-173 (2007).</li><li>Beck, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+electrode+placement+over+the+innervation+zone+on+electromyographic+amplitude+and+mean+power+frequency+versus+isokinetic+torque+relationships.">The influence of electrode placement over the innervation zone on electromyographic amplitude and mean power frequency versus isokinetic torque relationships.</a> Journal of neuroscience. 162, 72-83 (2007).</li><li>Beck, T. W., Stock, M. S., DeFreitas, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-frequency+analysis+of+surface+electromyographic+signals+during+fatiguing+isokinetic+muscle+actions.">Time-frequency analysis of surface electromyographic signals during fatiguing isokinetic muscle actions.</a> Journal of strength and conditioning research / National Strength, &amp; Conditioning Association. 26, 1904-1914 (2012).</li><li>Evetovich, T. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mean+power+frequency+and+amplitude+of+the+mechanomyographic+signal+during+maximal+eccentric+isokinetic+muscle+actions.">Mean power frequency and amplitude of the mechanomyographic signal during maximal eccentric isokinetic muscle actions.</a> Electromyography and clinical neurophysiology. 39, 123-127 (1999).</li><li>Blaesser, R. J., Couls, L. M., Lee, C. F., Zuniga, J. M., Malek, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparing+EMG+amplitude+patterns+of+responses+during+dynamic+exercise:+polynomial+versus+log-transformed+regression.">Comparing EMG amplitude patterns of responses during dynamic exercise: polynomial versus log-transformed regression.</a> Scandinavian journal of medicine, &amp; science in sports. In press, (2015).</li><li>Briscoe, M. J., Forgach, M. S., Trifan, E., Malek, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validating+the+EMGFT+from+a+single+incremental+cycling+testing.">Validating the EMGFT from a single incremental cycling testing.</a> International journal of sports medicine. 35, 566-570 (2014).</li><li>Zuniga, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuromuscular+and+metabolic+comparisons+between+ramp+and+step+incremental+cycle+ergometer+tests.">Neuromuscular and metabolic comparisons between ramp and step incremental cycle ergometer tests.</a> Muscle. 47, 555-560 (2013).</li><li>Mastalerz, A., Gwarek, L., Sadowski, J., Szczepanski, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+the+run+intensity+on+bioelectrical+activity+of+selected+human+leg+muscles.">The influence of the run intensity on bioelectrical activity of selected human leg muscles.</a> Acta of bioengineering and biomechanics / Wroclaw University of Technology. 14, 101-107 (2012).</li><li>Basmajian, J. V., De Luca, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Muscles alive, their functions revealed by electromyography. , (1985).</li><li>Vries, H. A., Moritani, T., Nagata, A., Magnussen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relation+between+critical+power+and+neuromuscular+fatigue+as+estimated+from+electromyographic+data.">The relation between critical power and neuromuscular fatigue as estimated from electromyographic data.</a> Ergonomics. 25, 783-791 (1982).</li><li>Vries, H. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+estimating+physical+working+capacity+at+the+fatigue+threshold+(PWCFT).">A method for estimating physical working capacity at the fatigue threshold (PWCFT).</a> Ergonomics. 30, 1195-1204 (1987).</li><li>Vries, H. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+affecting+the+estimation+of+physical+working+capacity+at+the+fatigue+threshold.">Factors affecting the estimation of physical working capacity at the fatigue threshold.</a> Ergonomics. 33, 25-33 (1990).</li><li>Astrand, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+physical+work+capacity+of+workers+50-64+years+old.">The physical work capacity of workers 50-64 years old.</a> Acta physiologica Scandinavica. 42, 73-86 (1958).</li><li>Hettinger, T., Birkhead, N. C., Horvath, S. M., Issekutz, B., Rodahl, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+physical+work+capacity.">Assessment of physical work capacity.</a> Journal of Applied Physiology. 16, 153-156 (1961).</li><li>Smith, J. L., Karwowsk, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> International encyclopedia of ergonomics and human factors. , (2006).</li><li>Kenny, G. P., Yardley, J. E., Martineau, L., Jay, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physical+work+capacity+in+older+adults:+implications+for+the+aging+worker.">Physical work capacity in older adults: implications for the aging worker.</a> American journal of industrial medicine. 51, 610-625 (2008).</li><li>Matsumoto, T., Ito, K., Moritani, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+anaerobic+threshold+and+electromyographic+fatigue+threshold+in+college+women.">The relationship between anaerobic threshold and electromyographic fatigue threshold in college women.</a> European journal of applied physiology. 63, 1-5 (1991).</li><li>Guffey, D. R., Gervasi, B. J., Maes, A. A., Malek, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimating+electromygraphic+and+heart+rate+fatigue+threshold+from+a+single+treadmill+test.">Estimating electromygraphic and heart rate fatigue threshold from a single treadmill test.</a> Muscle. 46, 577-581 (2012).</li><li>Camic, C. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+the+muscle+fiber+pennation+angle+and+innervation+zone+on+the+identification+of+neuromuscular+fatigue+during+cycle+ergometry.">The influence of the muscle fiber pennation angle and innervation zone on the identification of neuromuscular fatigue during cycle ergometry.</a> Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology. 21, 33-40 (2011).</li></ol>

The authors have nothing to disclose.

We here present a method for determining neuromuscular fatigue in the quadriceps femoris muscles for dynamic exercise. This method provides a straightforward and non-invasive approach to using surface EMG. Moreover, the versatility of this method is that researchers can adapt it to other modes of exercise such as the treadmill20.
Theoretically, for intensities at or below the EMG fatigue threshold the participant should be able to sustain the exercise workbout indefinitely12,13...

Surface electromyography (EMG) is a noninvasive approach of studying motor unit recruitment during isometric1-3, isokinetic4-6, or continuous7-10 muscle action. The amplitude of the EMG signal represents muscle activation which consists of the number of motor units activated, the firing rate of the motor units, or both11. The concept of the EMG fatigue threshold is used to indicate the highest workload in which an individual can exercise indefinitely without an increase in EMG amplitude8.
It is important to briefly discussion the origin of the EMG fatigue threshold. The original study by deVries et al.12 involved a protocol that consisted of multiple (usually 3 to 4) discontinuous work bouts, where the EMG amplitude was plotted versus time for each work bout. The power output was then plotted versus the slope coefficients from the EMG amplitude versus time relationship, and then extrapolated to zero slope (the y-intercept)12. The authors12 originally termed that protocol the physical working capacity at the fatigue threshold (PWCFT). In a another study, deVries et al.13 used discontinuous work bouts, but used linear regression to find the first power output that resulted in a significant slope for the EMG amplitude versus time relationship. The authors13 also termed that protocol the PWCFT, creating some confusion in the literature. In a subsequent article, deVries et al.14 modified their earlier protocol13 and developed a continuous incremental protocol. The EMG amplitude was plotted against time for each power output and the PWCFT was defined as the average of the highest power output that resulted in no change in EMG amplitude over time and the lowest power output that resulted in an increase in EMG amplitude over time14.
It should be noted that the term PWC was originally introduced in the late 1950s15,16 and is synonymous with a plethora of literature (past, present, and across different countries) examining aerobic capacity at a given workload17. Moreover, the term is used in the ergonomic and industrial literature which focus on day-to-day productivity of workers performing repetitive action during 8 hour work days such as individuals in an assembly plant18.
The term EMG fatigue threshold was initially used by Matsumoto and colleagues19 after they modified the deVries12 protocol where the power output versus slope coefficients of the EMG amplitude versus time relationship are plotted and extrapolated to the point of zero slope. More recently, Guffey et al.20 and Briscoe et al.8 used the method of deVries et al.14 and the terminology of Matsumoto et al.19 to operationally define the EMG fatigue threshold. Moving forward, we recommend that the term EMG fatigue threshold be used. Thus, the EMG amplitude versus time relationship is plotted for each power output and then analyzed using linear regression analyses (Figure 1). To estimate the EMG fatigue threshold, the highest power output with a non-significant (p &#62;0.05) slope and the lowest power output with a significant (p &#60;0.05) slope is identified and then the average is calculated14. This protocol is simple, convenient, and completed within 15-20 min. Moreover, the incremental rate can be modulated based on the individual&#8217;s level of habitual physical activity, and therefore has potential applications in clinical settings.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>839 E Monark cycle ergometer&#160;</td>
			<td>Monark Exercise AB</td>
			<td>839 E</td>
			<td></td>
		</tr>
		<tr>
			<td>Heart rate monitor</td>
			<td>Polar</td>
			<td>Polar H1</td>
			<td></td>
		</tr>
		<tr>
			<td>Laptop</td>
			<td>Dell Inspiron</td>
			<td>varies</td>
			<td>any laptop computer with USB slots should work.</td>
		</tr>
		<tr>
			<td>EMG amplifiers</td>
			<td>BioPac Systems, Inc.</td>
			<td>100B</td>
			<td>100C are the latest version</td>
		</tr>
		<tr>
			<td>Disposable EMG electrodes</td>
			<td>BioPac Systems, Inc.</td>
			<td>EL-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Sandpaper</td>
			<td>Home Depot</td>
			<td>9 in. x 11 in. 60 Grit course no-slip grip Advanced Sandpaper (3-Pack)</td>
			<td></td>
		</tr>
	</tbody>
</table>

determining the electromyographic fatigue threshold following a single visit exercise test

Theoretically, the electromyographic (EMG) fatigue threshold is the exercise intensity an individual can maintain indefinitely without the need to recruit more motor units which is associated with an increase in the EMG amplitude. Although different protocols have been used to estimate the EMG fatigue threshold they require multiple visits which are impractical for a clinical setting. Here, we present a protocol for estimating the EMG fatigue threshold for cycle ergometry which requires a single visit. This protocol is simple, convenient, and completed within 15-20 min, therefore, has the potential to be translated into a tool that clinicians can use in exercise prescription.

As shown in Figure 1, for a single participant, each power output that is completed has six data points that represent the EMG amplitude for the vastus lateralis muscle. Therefore, in this example, the highest power output with a non-significant (p &#62;0.05) slope is 200 watts, whereas the lowest power output with a significant (p &#60;0.05) slope is 225 W. Therefore, for this participant the EMG fatigue threshold is 213 W. Once the EMG fatigue threshold is determined for each particip...

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Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test

This protocol describes the electromyographic fatigue threshold which demarcates between nonfatiguing and fatiguing exercise workloads. This information could be used to develop a more individualized training program.

Theoretically, the electromyographic (EMG) fatigue threshold is the exercise intensity an individual can maintain indefinitely without the need to recruit ...

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12.5K Views.  Wayne State University. This protocol describes the electromyographic fatigue threshold which demarcates between nonfatiguing and fatiguing exercise workloads. This information could be used to develop a more individualized training program.

Video: Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test

Making Sense of Listening: The IMAP Test Battery

The ability to hear is only the first step towards making sense of the range of information contained in an auditory signal. Of equal importance are the abilities to extract and use the information encoded in the auditory signal. We refer to these as listening skills (or auditory processing AP). Deficits in these skills are associated with delayed language and literacy development, though the nature of the relevant deficits and their causal connection with these delays is hotly debated.
When a child is referred to a health professional with normal hearing and unexplained difficulties in listening, or associated delays in language or literacy development, they should ideally be assessed with a combination of psychoacoustic (AP) tests, suitable for children and for use in a clinic, together with cognitive tests to measure attention, working memory, IQ, and language skills. Such a detailed examination needs to be relatively short and within the technical capability of any suitably qualified professional. Current tests for the presence of AP deficits tend to be poorly constructed and inadequately validated within the normal population. They have little or no reference to the presenting symptoms of the child, and typically include a linguistic component. Poor performance may thus reflect problems with language rather than with AP. To assist in the assessment of children with listening difficulties, pediatric audiologists need a single, standardized child-appropriate test battery based on the use of language-free stimuli.
We present the IMAP test battery which was developed at the MRC Institute of Hearing Research to supplement tests currently used to investigate cases of suspected AP deficits. IMAP assesses a range of relevant auditory and cognitive skills and takes about one hour to complete. It has been standardized in 1500 normally-hearing children from across the UK, aged 6-11 years. Since its development, it has been successfully used in a number of large scale studies both in the UK and the USA. IMAP provides measures for separating out sensory from cognitive contributions to hearing. It further limits confounds due to procedural effects by presenting tests in a child-friendly game-format. Stimulus-generation, management of test protocols and control of test presentation is mediated by the IHR-STAR software platform. This provides a standardized methodology for a range of applications and ensures replicable procedures across testers. IHR-STAR provides a flexible, user-programmable environment that currently has additional applications for hearing screening, mapping cochlear implant electrodes, and academic research or teaching.

A test battery (IMAP) for performing an in-depth assessment of auditory and cognitive abilities contributing to listening skills is described. It is quick to administer, child-friendly and free from linguistic confounds. Stimulus generation and protocol management are controlled via a software platform (IHR-STAR) to ensure replicable procedures.

The ability to hear is only the first step towards making sense of the range of information contained in an auditory signal. Of equal importance are the ...

The Trier Social Stress Test Protocol for Inducing Psychological Stress

This article demonstrates a psychological stress protocol for use in a laboratory setting. Protocols that allow researchers to study the biological pathways of the stress response in health and disease are fundamental to the progress of research in stress and anxiety.1 Although numerous protocols exist for inducing stress response in the laboratory, many neglect to provide a naturalistic context or to incorporate aspects of social and psychological stress. Of psychological stress protocols, meta-analysis suggests that the Trier Social Stress Test (TSST) is the most useful and appropriate standardized protocol for studies of stress hormone reactivity.2 In the original description of the TSST, researchers sought to design and evaluate a procedure capable of inducing a reliable stress response in the majority of healthy volunteers.3 These researchers found elevations in heart rate, blood pressure and several endocrine stress markers in response to the TSST (a psychological stressor) compared to a saline injection (a physical stressor).3 Although the TSST has been modified to meet the needs of various research groups, it generally consists of a waiting period upon arrival, anticipatory speech preparation, speech performance, and verbal arithmetic performance periods, followed by one or more recovery periods. The TSST requires participants to prepare and deliver a speech, and verbally respond to a challenging arithmetic problem in the presence of a socially evaluative audience.3 Social evaluation and uncontrollability have been identified as key components of stress induction by the TSST.4 In use for over a decade, the goal of the TSST is to systematically induce a stress response in order to measure differences in reactivity, anxiety and activation of the hypothalamic-pituitary-adrenal (HPA) or sympathetic-adrenal-medullary (SAM) axis during the task.1 Researchers generally assess changes in self-reported anxiety, physiological measures (e.g. heart rate), and/or neuroendocrine indices (e.g. the stress hormone cortisol) in response to the TSST. Many investigators have adopted salivary sampling for stress markers such as cortisol and alpha-amylase (a marker of autonomic nervous system activation) as an alternative to blood sampling to reduce the confounding stress of blood-collection techniques. In addition to changes experienced by an individual completing the TSST, researchers can compare changes between different treatment groups (e.g. clinical versus healthy control samples) or the effectiveness of stress-reducing interventions.1

This article describes a protocol for inducing psychological stress in participants, which enables researchers to measure psychological, physiological and neuroendocrine responses to stress within single participants or between groups.

This article demonstrates a psychological stress protocol for use in a laboratory setting.  Protocols that allow researchers to study the biological ...

Computerized Dynamic Posturography for Postural Control Assessment in Patients with Intermittent Claudication

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic conditions. As part of a diagnostic assessment, the early detection of postural deficits is important so that appropriate and targeted interventions can be prescribed. The Sensory Organization Test (SOT) on the EquiTest determines an individual&#39;s use of the sensory systems (somatosensory, visual, and vestibular) that are responsible for postural control. Somatosensory and visual input are altered by the calibrated sway-referenced support surface and visual surround, which move in the anterior-posterior direction in response to the individual&#39;s postural sway. This creates a conflicting sensory experience. The Motor Control Test (MCT) challenges postural control by creating unexpected postural disturbances in the form of backwards and forwards translations. The translations are graded in magnitude and the time to recover from the perturbation is computed.
Intermittent claudication, the most common symptom of peripheral arterial disease, is characterized by a cramping pain in the lower limbs and caused by muscle ischemia secondary to reduced blood flow to working muscles during physical exertion. Claudicants often display poor balance, making them susceptible to falls and activity avoidance. The Ankle Brachial Pressure Index (ABPI) is a noninvasive method for indicating the presence of peripheral arterial disease and intermittent claudication, a common symptom in the lower extremities. ABPI is measured as the highest systolic pressure from either the dorsalis pedis or posterior tibial artery divided by the highest brachial artery systolic pressure from either arm. This paper will focus on the use of computerized dynamic posturography in the assessment of balance in claudicants.

Individuals with intermittent claudication exhibit poor balance compared to healthy controls. Computerized dynamic posturography is an objective method for measuring an individual's postural responses to balance disturbances. This provides an objective reflection of the person&#x2019;s ability to respond to situations under which sensory stimuli are altered and unexpected perturbations occur.

Computerized dynamic posturography with the EquiTest is an objective technique for measuring postural strategies under challenging static and dynamic ...

A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis. Damage to the endothelium may predispose the vessel to atherosclerosis and increase the risk for cardiovascular disease. Assessments of peripheral endothelial function are good indicators of early abnormalities in the vascular wall and correlate well with assessments of coronary endothelial function. The present manuscript details the important methodological steps necessary for the assessment of microvascular endothelial function using laser Doppler imaging with iontophoresis, large vessel endothelial function using flow-mediated dilatation, and carotid atherosclerosis using carotid artery ultrasound. A discussion on the methodological considerations for each of the techniques is also presented, and recommendations are made for future research.

The present article describes the methodological considerations for several non-invasive assessments of vascular function and morphology that are commonly used in medical research to assess different stages of atherosclerosis.

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis.  Damage to the endothelium may ...

Ultrasound Assessment of Endothelial Function: A Technical Guideline of the Flow-mediated Dilation Test

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a pathological condition characterized mainly by a disruption in the balance between vasodilator and vasoconstrictor substances and is proposed to play an important role in the development of atherosclerotic cardiovascular disease. Therefore, a precise evaluation of endothelial function in humans represents an important tool that could help better understand the etiology of multiple cardio-centric pathologies.
Over the past twenty-five years, many methodological approaches have been developed to provide an assessment of endothelial function in humans. Introduced in 1989, the FMD test incorporates a forearm occlusion and subsequent reactive hyperemia that promotes nitric oxide production and vasodilation of the brachial artery. The FMD test is now the most widely utilized, non-invasive, ultrasonic assessment of endothelial function in humans and has been associated with future cardiovascular events.
Although the FMD test could have clinical utility, it is a physiological assessment that has inherited several confounding factors that need to be considered. This article describes a standardized protocol for determining FMD including the recommended methodology to help minimize the physiological and technical issues and improve the precision and reproducibility of the assessment.

The flow mediated dilation (FMD) test is the most commonly utilized, non-invasive, ultrasound assessment of endothelial function in humans. Although the FMD test has been related with the prediction of future cardiovascular disease and events, it is a physiological assessment with many inherent confounding factors that need to be considered.

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a ...

Experimental Protocol of a Three-minute, All-out Arm Crank Exercise Test in Spinal-cord Injured and Able-bodied Individuals

Reliable exercise protocols are required to test changes in exercise performance in elite athletes. Performance improvements in these athletes may be small; therefore, sensitive tools are fundamental to exercise physiology. There are currently many exercise tests that allow for the examination of exercise capacity in able-bodied athletes, with protocols mainly for lower-body or whole-body exercise. There is a trend to test athletes in a sport-specific setting that closely resembles the actions that the participants are used to performing. Only a few protocols test short-term, high-intensity exercise capacity in participants with an impairment of the lower body. Most of these protocols are very sport-specific and are not applicable to a wide range of athletes. One well-known test protocol is the 30 s Wingate test, which is well-established in cycling and in arm crank exercise testing. This test analyzes high-intensity exercise performance over a 30 s time duration. In order to monitor exercise performance over a longer duration, a different method was modified for application to the upper body. The 3 min, all-out arm crank ergometer test allows athletes to be tested in a manner specific to 1,500 m wheelchair racing (in terms of exercise duration), as well as to upper body exercises such as rowing or hand-cycling. In order to increase the reliability with identical test conditions, it is crucial to precisely replicate settings such as the resistance (i.e., torque factor) and the position of the participants (i.e., the height of the crank, the distance between the crank and the participant, and the fixation of the participant). Another important issue concerns the beginning of the exercise test. Fixed revolutions per minute are required to standardize the test conditions for the start of the exercise test. This exercise protocol shows the importance of accurate operations to reproduce identical test conditions and settings.

We present a protocol to test the aerobic and anaerobic power of the upper body muscles over a duration of 3 min in able-bodied as well as in paraplegic and tetraplegic individuals. The protocol presents specific modifications in its application for upper-body exercise in individuals with or without disability.

Reliable exercise protocols are required to test changes in exercise performance in elite athletes. Performance improvements in these athletes may be ...

A Technique for Subcutaneous Abdominal Adipose Tissue Biopsy via a Non-diathermy Method

Adipose tissue biopsies offer tissue samples that, upon analysis, may provide insightful overviews of mechanisms relating to metabolism and disease. To obtain subcutaneous adipose tissue biopsies in the abdominal area, researchers and physicians use either a surgical or a needle-based technique. However, surgical subcutaneous fat biopsies can offer tissue samples that may provide a more comprehensive overview of the complexities of biological indices in white adipose tissue. Usually, a surgical adipose tissue biopsy includes a diathermy treatment for cauterizing blood vessels to prevent excessive bleeding. Nevertheless, side effects, such as flash fires and skin lesions in the tissue, have been reported after diathermy. Therefore, we aimed to standardize a surgical abdominal adipose tissue biopsy performed under local anesthesia using a non-diathermy method. We conducted 115 subcutaneous adipose tissue biopsies in healthy men using a non-diathermy abdominal surgical biopsy method. Our results showed three cases of excessive post-operation bleeding out of 115 operations (2.61%).In conclusion, our standardized subcutaneous abdominal adipose tissue surgical biopsy using a non-diathermy method can be safely applied to healthy men at the bedside, with minimal side effects.

We standardized an abdominal adipose tissue biopsy using a non-diathermy method performed under local anesthesia. Three cases of excessive post-operation bleeding out of 115 operations (2.61%) occurred.We conclude that an abdominal adipose tissue surgical biopsy using a non-diathermy method can be safely applied to healthy men.

Adipose tissue biopsies offer tissue samples that, upon analysis, may provide insightful overviews of mechanisms relating to metabolism and disease. To ...

Taste Exam: A Brief and Validated Test

The emerging importance of taste in medicine and biomedical research, and new knowledge about its genetic underpinnings, has motivated us to supplement classic taste-testing methods in two ways. First, we explain how to do a brief assessment of the mouth, including the tongue, to ensure that taste papillae are present and to note evidence of relevant disease. Second, we draw on genetics to validate taste test data by comparing reports of perceived bitterness intensity and inborn receptor genotypes. Discordance between objective measures of genotype and subjective reports of taste experience can identify data collection errors, distracted subjects or those who have not understood or followed instructions. Our expectation is that fast and valid taste tests may persuade researchers and clinicians to assess taste regularly, making taste testing as common as testing for hearing and vision. Finally, because many tissues of the body express taste receptors, taste responses may provide a proxy for tissue sensitivity elsewhere in the body and, thereby, serve as a rapid, point-of-care test to guide diagnosis and a research tool to evaluate taste receptor protein function.

This protocol measures human taste responses and includes a brief anatomical assessment, a short taste test, and a validation method using the subject&#39;s reported sensation and taste receptor genotype.

The emerging importance of taste in medicine and biomedical research, and new knowledge about its genetic underpinnings, has motivated us to supplement ...

'Boden Food Plate': Novel Interactive Web-based Method for the Assessment of Dietary Intake

Different methods can be used in research to assess dietary intake, many of which are still paper-based. Written estimated food diaries are often utilized in clinical trials, despite being a burden for both study participants and researchers. This method requires participant literacy, it is time consuming, labor intensive, and can easily lead to under-reporting. With advancements in technology, there is a growing interest in electronic diaries that automate the dietary assessment process. These are focused on improving accuracy, reducing both time and cost and providing users with a visual and more enjoyable experience. The methodology presented here aimed to validate the &#39;Boden Food Plate&#39;, a novel web-based platform for self-recording of food and drink items, compared to a traditional estimated food diary. The application was also rated on a satisfaction scale by study participants using a paper-based questionnaire. Sixty-seven participants completed the dietary measures on both the three-day electronic and paper food diaries. For the analysis, only dietary data completed at both study time points (baseline and week six) was utilized. Despite small mean differences between dietary data collection methods, Bland Altman analysis showed fairly wide 95% limits of agreement between the electronic platform and the written estimated food diary and there were few cases which did not fall within the 95% confidence intervals. Overall, participants found the electronic food diary to be more fun than the paper method and as easy to use as hard copy diaries. The new platform has potential as a self-recording tool for the collection of dietary data, particularly when utilized in clinical trial settings. However, further validation studies are needed to improve the validity of this novel electronic dietary data collection tool.

The &#39;Boden Food Plate&#39; is an electronic food diary designed to be an interactive and fun method to collect dietary intake using visual depictions. The purpose of this study was to validate the web-based application against a traditional three-day estimated food diary method.

Different methods can be used in research to assess dietary intake, many of which are still paper-based. Written estimated food diaries are often utilized ...

Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans

Regular physical activity has a positive effect on human health, but the mechanisms controlling these effects remain unclear. The physiologic and biologic responses to acute exercise are predominantly influenced by the duration and intensity of the exercise regimen. As exercise is increasingly thought of as a therapeutic treatment and/or diagnostic tool, it is important that standardizable methodologies be utilized to understand the variability and to increase the reproducibility of exercise outputs and measurements of responses to such regimens. To that end, we describe two different cycling exercise regimens that yield different physiologic outputs. In a maximal exercise test, exercise intensity is continually increased with a greater workload resulting in an increasing cardiopulmonary and metabolic response (heart rate, stroke volume, ventilation, oxygen consumption and carbon dioxide production). In contrast, during endurance exercise tests, the demand is increased from that at rest, but is raised to a fixed submaximal exercise intensity resulting in a cardiopulmonary and metabolic response that typically plateaus. Along with the protocols, we provide suggestions on measuring physiologic outputs that include, but are not limited to, heart rate, slow and forced vital capacity, gas exchange metrics, and blood pressure to enable the comparison of exercise outputs between studies. Biospecimens can then be sampled to assess cellular, protein, and/or gene expression responses. Overall, this approach can be easily adapted into both short- and long-term effects of two distinct exercise regimens.

To assess the influence of exercise intensity on physiologic and biologic responses, two different exercise testing protocols were utilized. Methods outlining exercise testing on a cycle ergometer as an incremental maximal oxygen consumption test and endurance, steady state submaximal endurance test are described.

Regular physical activity has a positive effect on human health, but the mechanisms controlling these effects remain unclear. The physiologic and biologic ...