All human participants provided informed consent. The protocol was part of a study approved by the Institutional Review Board of the University of Central Florida. Inclusion criteria included ages 18 -45 and physically active according to ACSM guidelines (30 min of moderate to vigorous activity 5 days per week)19. Exclusion criteria included low back pain within the past year, current hip, upper, or lower extremity pain or injury, a year history of low back surgery or lower extremity surgery, self-reported balance disorder, muscular abnormalities, currently pregnant, or having an open wound in the abdominal area (Table 1).
1. Data collection instrument preparation
<ol>
	<li>Check the integrity of the ultrasound machine and sEMG machine (see Table of Materials).
	<ol>
		<li>Turn on the ultrasound machine, press Patient, and add a new patient. Click New Patient and enter the patient identification number. Select MSK exam type &#62; Abdominal preset and press Register. Press Exit.</li>
		<li>Turn on the tablet (see Table of Materials) and click the EMG recording application. Click the Menu button in the top left screen and scan for sensors. Take the sensor out of the base and hover over the activation button. Once the sensor is connected with the application, create a new folder with the participant&#39;s identification number. 
		NOTE: Ultrasound settings in Abdominal Preset, B-mode: B color = Tint Map D, Write Zoom Height = 4, Write Zoom Width = 4, Thermal Index = Tls, ATO Level = Low, Focus Number = 2, Focus Number CrossXBeam = 2, Focus Depth = 50, Depth (cm) = 3, Compression = 1, Focus Width = 1, Focus Width CrossXBeam = 1, Line Density = 3, Line Density CrossXBeam = 3, Suppression = 0, Frame Average = 4, From Average CrossXBeam = 2, CrossXBeam = 2, CrossXBeam # = Low, CrossXBeam Type = Mean, Edge Enhance = 3, B Steer = 0, Gray Scale Map = Gray Map C, Gain = 34, Dynamic Range = 69, Rejection = 0, Frequency (MHz) = 12. Ultrasound settings in Abdominal Preset, M-mode: sweep speed = 0, M color = Tint Map C, Dop Display Format = Vert &#189; B, Rejection = 0, Compression = 1, Gray Scale Map = Gray Map D, M Gain (delta from B) = 0.</li>
	</ol>
	</li>
</ol>
2. Surface electromyography preparation (see Table of Materials)
<ol>
	<li>Determine the external oblique sensor location by palpating the right iliac crest and right inferior rib while the participant is supine hook-lying (Figure 1). Place the sensor 3 cm anterior from the midway point between the lower rib and the iliac crest, parallel to the muscle fibers20.</li>
	<li>Shave, clean, and debride the area of the skin where the sensor (see Table of Materials) will be placed. Add adhesive (see Table of Materials) to the sensor and secure onto skin.</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/64335/64335fig01.jpg" /> 
Figure 1: Examination location of the lateral abdominal wall. The sEMG sensor is placed 3 cm anterior from the midway point between the lower rib and the iliac crest, parallel to the muscle fibers20.&#160;The transducer is located 10 cm lateral to the umbilicus until the lateral abdominal wall is visible on the screen. <a href="https://www.jove.com/files/ftp_upload/64335/64335fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
3. Ultrasound preparation (see Table of Materials)
<ol>
	<li>In a standing position, place the transducer through the elastic belt and foam block (Figure 2).</li>
	<li>Add gel to the transducer and place the transducer 10 cm lateral to the umbilicus. Adjust until the lateral abdominal wall is visible on the screen21 (Figure 3).</li>
	<li>Ensure that the transducer is tightly secured to the lateral abdominal wall.</li>
	<li>Secure the belt with the velcro straps. Adjust the depth to obtain optimal image quality in B-Mode (Figure 4).</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/64335/64335fig02.jpg" /> 
Figure 2: Transducer placed through the elastic belt and foam block. <a href="https://www.jove.com/files/ftp_upload/64335/64335fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/64335/64335fig03.jpg" /> 
Figure 3: Example of resting image to verify the lateral abdominal wall. <a href="https://www.jove.com/files/ftp_upload/64335/64335fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/64335/64335fig04.jpg" /> 
Figure 4: Transducer secured on the lateral abdominal wall by the elastic belt and foam block. <a href="https://www.jove.com/files/ftp_upload/64335/64335fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
4. Ultrasound static side plank
<ol>
	<li>On a yoga mat (see Table of Materials), instruct the participant to lay on their right side with their elbow in 90 degrees of flexion, so their trunk and upper extremity are raised off the ground. The participant&#39;s feet should be stacked on each other with the knees fully extended. The legs should be parallel touching the yoga mat.</li>
	<li>Press Freeze then Store for each image to capture three static ultrasound images of the lateral abdominal wall. 
	NOTE: Saved images will be located below the active image screen.</li>
</ol>
5. sEMG static side plank
NOTE: Simultaneously, the researcher will also obtain the sEMG output during the static positioning described in step 4.1.
<ol>
	<li>In the sEMG menu in the top left screen of the EMG recording application, select Settings, which is a gear icon.
	<ol>
		<li>Once in the sensor settings page, select the bicep icon. This will open the page for normalization measurements.</li>
		<li>Press Click Play to Begin; there will be a 5 s countdown. During this period, instruct the patient to assume the testing position. The recording will take an additional 5 s.</li>
		<li>Record the &#34;MVC = .XXXXmV&#34;, as this will be used for normalization calculation. 
		&#8203;NOTE: The EMG mobile suite automatically band pass filters between 20 -450 Hz. EMG (RMS) 333.3, 1125 ms window width.</li>
	</ol>
	</li>
</ol>
6. Side plank
<ol>
	<li>Next, instruct the participant to complete the side plank for 60 s maintaining the correct form22. Press the M on the ultrasound machine to turn on M-mode.</li>
	<li>Press Plot, press the red button and press the Save button again in the EMG application. The participant will be given a 3 s countdown. Once that countdown commences, press Store on the ultrasound to begin the ultrasound recording. 
	NOTE: The participant will hold the correct form until 60 s, or when the researcher determines that the correct form has been disrupted.</li>
	<li>To save the recorded M-mode video, press Store once the exercise has stopped and the Stop button on the sEMG application.</li>
	<li>Click Save file as and type in a filename to save the output, which will appear on the screen when the recording is stopped.</li>
</ol>
7. Ultrasound static dead bug
<ol>
	<li>On the yoga mat, instruct the participant to lay supine with their legs in a hook-lying position.</li>
	<li>Press B to enter brightness mode. Press&#160;Freeze and then Store for each image to capture three static images of the lateral abdominal wall via ultrasound. Saved images will be located below the active image screen.</li>
</ol>
8. sEMG static dead bug
<ol>
	<li>In the menu of the EMG application (top left), select Settings, which is a gear icon.</li>
	<li>Once in the sensor settings page, select the bicep icon. This will open the page for normalization measurements.</li>
	<li>Press Click Play to Begin. During the 5 s countdown, instruct the patient to assume the testing position. The recording will take an additional 5 s.</li>
	<li>Record the &#34;MVC = .XXXXmV&#34;, as this will be used for normalization calculation.</li>
</ol>
9. Dead bug
<ol>
	<li>Next, instruct the participant to complete the dead bug for 60 s, maintaining the correct form. Press the M on the ultrasound machine to turn on M-mode.</li>
	<li>Instruct the participant to maximally extend their right shoulder while maximally extending their left hip and knee, while also maintaining the starting position of the contralateral extremities.</li>
	<li>Instruct the participant to then flex their shoulder, hip, and knee to return to the starting position. The contralateral extremities will then perform the same motion.</li>
	<li>Ask the participant to perform the exercise to a metronome set to 45 beats per min. This results in 22 repetitions of the dead bug in 60 s. 
	NOTE: The participant should hold the correct form until 60 s, or until the researcher determines that the correct form has been disrupted or the metronome rhythm has been interrupted.</li>
	<li>Press&#160;Plot, press the&#160;red&#160;button and then press Play. Press the&#160;Save&#160;button again in the EMG application.&#160;The participant will be given a 3 s countdown. Once that countdown commences, press Store on the ultrasound to begin the ultrasound recording.</li>
</ol>
10. Ultrasound static measurement
<ol>
	<li>Click Enter when the first static image you want to measure is selected.</li>
	<li>Press Measure to open the measurement tool. Measure the maximal muscle thickness during the static positions in centimeters from the superior inferior fascial border to the inferior superior fascial border (Figure 5 [side plank] and Figure 6 [dead bug]).</li>
	<li>Click Enter at the superior inferior border and Enter again at the inferior superior border.</li>
	<li>Repeat steps 10.1-10.3 for side plank and dead bug static measurements. Average the measurements of the three static images.</li>
</ol>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/64335/64335fig05.jpg" /> 
Figure 5: Example of lateral abdominal wall during the side plank static, exercise starting position and measurements of muscles. A = external oblique (0.554 cm), B = internal oblique (0.761 cm), and C = transverse abdominis (0.326 cm). <a href="https://www.jove.com/files/ftp_upload/64335/64335fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/64335/64335fig06.jpg" /> 
Figure 6: Example of lateral abdominal wall in the dead bug static, exercise starting position and measurements of muscles. A = external oblique (0.618 cm), B = internal oblique (0.820 cm), and C = transverse abdominis (0.438 cm). <a href="https://www.jove.com/files/ftp_upload/64335/64335fig06large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
11. Ultrasound dynamic measurements
<ol>
	<li>Measure the maximal thickness of the external oblique, internal oblique, and transverse abdominis thickness during the first 5 s and last 5 s of the exercise. Additionally, record the maximal thickness over the entire 60 s. 
	NOTE: The side plank is commonly performed for durations of 5 s. Taking sets and repetition guidelines from previous authors, a longer duration of 60 s was chosen for comparison in this protocol. The first 5 s and last 5 s of the task were compared to evaluate both the strength and endurance aspects of the muscle group23,24.</li>
	<li>Using the Scroll button, find the first 5 s and last 5 s of each exercise. Additionally, visually inspect for the greatest thickness of each muscle throughout the 60 s exercise.</li>
	<li>Press Measure to open the measurement tool. Measure the maximal muscle thickness during the static positions in centimeters from the superior inferior fascial border to the inferior superior fascial border (Figure 7 [side plank] and Figure 8 [dead bug]).</li>
	<li>Divide each of the three thickness measurements obtained during the exercises by the averaged static position to obtain an activation ratio 25.</li>
</ol>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/64335/64335fig07.jpg" /> 
Figure 7: Example of lateral abdominal wall during the side plank exercise and measurements of muscles in M-mode. A = external oblique (0.968 cm), B = internal oblique (0.937 cm), and C = transverse abdominis (0.714 cm). <a href="https://www.jove.com/files/ftp_upload/64335/64335fig07large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/64335/64335fig08.jpg" /> 
Figure 8: Example of lateral abdominal wall during the dead bug exercise and measurements of muscles in M-mode. A = external oblique (0.840 cm), B = internal oblique (0.840 cm), and C = transverse abdominis (0.720 cm). <a href="https://www.jove.com/files/ftp_upload/64335/64335fig08large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
12. sEMG Measurement
<ol>
	<li>Press the Home icon on the EMG data recording page. Select the folder icon in the top right corner of the screen. The saved output from the static and exercise trials will be saved here. Convert each file to an .xlsx file. Export the .xlsx file.</li>
	<li>In a spreadsheet, obtain the maximum values during the first and last 5 s, and the overall maximum value.</li>
	<li>Divide the static sEMG output obtained in steps 5 (static side plank sEMG) and 8 (dead bug sEMG) by the output during the exercises, respectively.</li>
</ol>

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The authors declare no conflicts of interest related to this manuscript.

M-mode ultrasound provides onset of muscle tissue movement and muscle thickness change during real time observation of anatomy over a selected time21. M-mode ultrasound combined with sEMG provides an overall understanding of muscle function, including electrical representation and visual observation. These instruments can be used in tandem during exercise to provide researchers with a global understanding of muscle function.
Specific training of ultrasound and sEMG tech...

The lateral abdominal wall is made up of the transverse abdominis, internal oblique, and external oblique1. The lateral abdominal wall contracts concentrically, eccentrically, and isometrically to withstand the forces placed on the body1. The co-contraction of this muscle group provides stabilization of the center of the human body2,3. These muscles are important during the prevention and rehabilitation of lower extremity injuries because poor trunk function is associated with increased hip adduction and knee valgus, which are risk factors for lower extremity injuries4,5. Focusing on strengthening and increasing muscular endurance of the core musculature not only decreases risk factors for the lower extremity but can also decrease low back pain6. Recently, it has been recommended that individuals who are suffering from acute and chronic low back pain should include trunk strengthening, endurance, and specific trunk muscle activation in their rehabilitation6. An example of specific trunk muscle activation is targeting isolated or grouped trunk muscles using co-contraction to restore control or increase coordination of the lumbopelvic-hip region6.
Two ways to objectively measure muscle function are the use of motion mode (M-mode) ultrasound and surface electromyography (sEMG). M-mode ultrasound provides a real-time visualization of muscle and fascia movement during a recorded time which can display onset and extent of the motion7. The distance between the superior inferior fascial border and inferior superior fascial border are measured at a selected time to obtain muscle thickness. Muscle thickness during a specific time point of an exercise can be divided by resting thickness to achieve an activation ratio8. sEMG provides insight into muscle activation and fatigue, as the output can be compared to the muscle&#39;s maximum contraction9. These two instruments and methods have been used previously to measure the onset of hip muscle activation during a variety of exercises in healthy and injured individuals10. Exercises that target the trunk, and specifically the lateral abdominal wall, are the side plank and dead bug11,12,13. The side plank is performed in a side lying position with the elbow directly underneath the shoulder and forearm on the ground, the hips are raised off the ground until the spine is in a neutral position. The knees are extended, and the feet are placed on top of one another9 (Supplemental Figure 1). The dead bug is performed in a supine position with both arms straight above and the hips and knees flexed in a 90&#176; angle. The exercise begins when one arm is flexed above the head and the contralateral leg extends. The opposite arm and leg remain in a neutral position and then flex and extend once the original moving arm and leg return to the neutral position13 (Supplemental Figure 2 and Supplemental Figure 3).
The activation of the external oblique has been seen to range from 37% to 62% of maximum voluntary isometric contraction (MVIC) during the side plank11,12,14. During the dead bug, the activation of the external oblique has been recorded between 20% to 30% of MVIC for only five repetitions of the exercise15. The internal oblique and transverse abdominis, the deeper abdominal muscles of the lateral abdominal wall, activate between 22% to 28% of MVIC during the side plank12,14. Due to the overlapping nature of the internal oblique and transverse abdominis, the two muscles have been combined during sEMG collection14. A limitation of sEMG is the crosstalk from adjacent muscles, where the sEMG sensor may be producing an output of a different muscle, resulting in a false understanding of activation16. Muscle thickness measurements obtained with ultrasound can be used to mitigate this limitation, and this measurement is feasible during trunk exercises, such as the isometric holds previously mentioned17.
Muscle thickness of the lateral abdominal wall has been recorded during the side plank as an absolute magnitude of difference between contracted thickness and rested thickness. At the 30 s time point of a side plank, the muscle thickness of the internal oblique and external oblique increased by 0.526 mm and 0.205 mm, respectively17. These measurements were recorded in brightness mode ultrasound at one time point during the side plank. B-mode ultrasound is commonly performed to assess before and after images; however, this method only allows for measurement at two time points18. M-mode ultrasound provides increased advantages compared to B-mode ultrasound, as it can detect onset of muscle activation as well as muscle thickness during the entirety of the exercise with any time point able to be selected for measurement18. Therefore, the overall goal of the current protocol is to provide an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises. This is beneficial to researchers and clinicians to understand how muscles function throughout the duration of an exercise, especially of an endurance nature, as opposed to a measurement isolated to a single time point.

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</table>

muscle function obtained with motion mode ultrasound and surface electromyography during core endurance exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

The measurements of both ultrasound and sEMG during the static, exercise starting position are represented in Table 2. These numbers will be used as the denominator when calculating the activation ratio. The thickness values of external oblique, internal oblique, and transverse abdominis during the first 5 s, last 5 s, and total duration (60 s) are in Table 3. These numbers are divided by the numbers in Table 2. The sEMG values normalized to static, exercise starting pos...

Watch this Scientific Journal Video about Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise at JoVE.com

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...

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3.0K Views.  University of Central Florida. This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises. 

Video: Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health disorders such as chronic wounds. We report the development of a dual-mode imaging system for non-invasive and non-contact imaging of cutaneous tissue oxygenation and vascular function. The imaging system integrated an infrared camera, a CCD camera, a liquid crystal tunable filter and a high intensity fiber light source. A Labview interface was programmed for equipment control, synchronization, image acquisition, processing, and visualization. Multispectral images captured by the CCD camera were used to reconstruct the tissue oxygenation map. Dynamic thermographic images captured by the infrared camera were used to reconstruct the vascular function map. Cutaneous tissue oxygenation and vascular function images were co-registered through fiduciary markers. The performance characteristics of the dual-mode image system were tested in humans.

A dual-mode imaging system was developed for non-contact assessment of cutaneous tissue oxygenation and vascular function.

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health ...

In Vivo Canine Muscle Function Assay

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric 
contractions. The pelvic limb of an anesthetized dog is immobilized in a stereotactic frame to align the tibia at a right angle to the femur. Adhesive wrap affixes the 
paw to a pedal mounted on the shaft of a servomotor to measure torque. Percutaneous nerve stimulation activates pelvic limb muscles of the paw to either push (extend) or 
pull (flex) against the pedal to generate isometric torque. Percutaneous tibial nerve stimulation activates tibiotarsal extensor muscles. Repeated eccentric (lengthening) 
contractions are induced in the tibiotarsal flexor muscles by percutaneous peroneal nerve stimulation. The eccentric protocol consists of an initial isometric contraction 
followed by a forced stretch imposed by the servomotor. The rotation effectively lengthens the muscle while it contracts, e.g., an eccentric contraction. During 
stimulation flexor muscles are subjected to an 800 msec isometric and 200 msec eccentric contraction. This procedure is repeated every 5 sec. To avoid fatigue, 4 min rest 
follows every 10 contractions with a total of 30 contractions performed.

In Vivo Canine Muscle Function Assay

We describe a minimally-invasive and painless method to measure canine hindlimb muscle strength and muscle response to repeated eccentric contractions.

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric 
...

Diagnostic Ultrasound Imaging of Mouse Diaphragm Function

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive surgical procedures. Although this is an effective method of assessing in vitro diaphragm activity, it involves non-survival surgery. The application of non-invasive ultrasound imaging as an in vivo procedure is beneficial since it not only reduces the number of animals sacrificed, but is also suitable for monitoring disease progression in live mice. Thus, our ultrasound imaging method may likely assist in the development of novel therapies that alleviate muscle injury induced by various respiratory diseases. Particularly, in clinical diagnoses of obstructive lung diseases, ultrasound imaging has the potential to be used in conjunction with other standard tests to detect the early onset of diaphragm muscle fatigue. In the current protocol, we describe how to accurately evaluate diaphragm contractility in a mouse model using a diagnostic ultrasound imaging technique.

Diagnostic ultrasound imaging has proven to be effective in diagnosing various respiratory diseases in human and animal subjects. We demonstrate a comprehensive ultrasound protocol utilized by Dr. Zuo's lab to analyze diaphragm kinetics specifically in mouse models. This is also a non-invasive research technique which can provide quantitative information on mouse respiratory muscle function.

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive ...

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 Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow reserve (CFR) in humans. Reduced CFR is accompanied by marked intramyocardial and pericoronary fibrosis and is used as an indication of the severity of dysfunction. This study explores, step-by-step, the real-time changes measured in the coronary flow velocity, CFR and systolic to diastolic peak velocity (S/D) ratio in the setting of an aortic banding model in mice. By using a Doppler transthoracic imaging technique that yields reproducible and reliable data, the method assesses changes in flow in the septal coronary artery (SCA), for a period of over two weeks in mice, that previously either underwent aortic banding or thoracotomy. 
During imaging, hyperemia in all mice was induced by isoflurane, an anesthetic that increased coronary flow velocity when compared with resting flow. All images were acquired by a single imager. Two ratios, (1) CFR, the ratio between hyperemic and baseline flow velocities, and (2) systolic (S) to diastolic (D) flow were determined, using a proprietary software and by two independent observers. Importantly, the observed changes in coronary flow preceded LV dysfunction as evidenced by normal LV mass and fractional shortening (FS). 
The method was benchmarked against the current gold standard of coronary assessment, histopathology. The latter technique showed clear pathologic changes in the coronary artery in the form of peri-coronary fibrosis that correlated to the flow changes as assessed by echocardiography. 
The study underscores the value of using a non-invasive technique to monitor coronary circulation in mouse hearts. The method minimizes redundant use of research animals and demonstrates that advanced ultrasound-based indices, such as CFR and S/D ratios, can serve as viable diagnostic tools in a variety of investigational protocols including drug studies and the study of genetically modified strains.

Coronary flow reserve (CFR) is useful for assessment of myocardial oxygen demand and evaluation of cardiovascular risk. This study establishes a step-by-step transthoracic Doppler echocardiographic (TTDE) method for longitudinal monitoring of the changes in CFR, as measured from coronary artery in mice, under the experimental pressure overload of aortic banding.

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow ...

Treating SCA1 Mice with Water-Soluble Compounds to Non-Specifically Boost Mitochondrial Function

Mitochondrial dysfunction plays a significant role in the aging process and in neurodegenerative diseases including several hereditary spinocerebellar ataxias and other movement disorders marked by progressive degeneration of the cerebellum. The goal of this protocol is to assess mitochondrial dysfunction in Spinocerebellar ataxia type 1 (SCA1) and assess the efficacy of pharmacological targeting of metabolic respiration via the water-soluble compound succinic acid to slow disease progression. This approach is applicable to other cerebellar diseases and can be adapted to a host of water-soluble therapies.
Ex vivo analysis of mitochondrial respiration is used to detect and quantify disease-related changes in mitochondrial function. With genetic evidence (unpublished data) and proteomic evidence of mitochondrial dysfunction in the SCA1 mouse model, we evaluate the efficacy of treatment with the water-soluble metabolic booster succinic acid by dissolving this compound directly into the home cage drinking water. The ability of the drug to pass the blood brain barrier can be deduced using high performance liquid chromatography (HPLC). The efficacy of these compounds can then be tested using multiple behavioral paradigms including the accelerating rotarod, balance beam test and footprint analysis. Cytoarchitectural integrity of the cerebellum can be assessed using immunofluorescence assays that detect Purkinje cell nuclei and Purkinje cell dendrites and soma. These methods are robust techniques for determining mitochondrial dysfunction and the efficacy of treatment with water-soluble compounds in cerebellar neurodegenerative disease.

We present a biochemical and behavioral protocol to evaluate the efficacy of mitochondria-targeted water-soluble compounds for the treatment of Spinocerebellar ataxia type 1 (SCA1) and other cerebellar neurodegenerative diseases.

Mitochondrial dysfunction plays a significant role in the aging process and in neurodegenerative diseases including several hereditary spinocerebellar ...

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 ...

Exergaming in Older People Living with HIV Improves Balance, Mobility and Ameliorates Some Aspects of Frailty

Approximately 1.2 million people in the United States live with HIV infection. Medical advancements have increased the life expectancy and this cohort is aging. HIV-positive individuals have a high incidence of frailty (~20%) characterized by depression and sedentary behavior. Exercise would be healthy, but due to the frail status of many HIV-positive individuals, conventional exercise is too taxing. The aim of this study was to evaluate the effectiveness and acceptability of a novel game-based training program (exergame) in ameliorating some aspects of frailty in HIV-infected individuals. Ten older people living with HIV were enrolled in an exergame intervention. Patients performed balance exercises such as weight shifting, ankle reaching, and obstacle crossing. Real-time visual/audio lower-extremity joint motion feedback was provided using wearable sensors to assist feedback and encourage subjects to accurately execute each exercise task. Patients trained twice a week for 45 min for 6 weeks. Changes in balance, gait, psychosocial parameters and quality of life parameters were assessed at the beginning, midterm and at conclusion of the training program. Ten patients completed the study and their results analyzed. The mean age was 57.2 &#177; 9.2 years. The participants showed a significant reduction in center of mass sway (78.2%, p = .045) during the semi-tandem balance stance with eyes closed and showed a significant increase in gait speed during a dual task motor-cognitive assessment (9.3%, p = .048) with an increase in stride velocity of over 0.1 m/sec. A significant reduction in reported pain occurred (43.5%, p = .041). Preliminary results of this exergame intervention show promise in improving balance and mobility while requiring older people living with HIV to be more active. The exergame can be continued at home and may have long term as well as short-term benefits for ameliorating frailty associated with HIV infection.

Persons infected with HIV are often frail, depressed and live a sedentary lifestyle for which conventional exercise is too taxing. Here, we present an exercise protocol that ameliorates aspects of frailty in HIV-infected persons. An exergame integrating cognitive control was developed using biosensors that measured balance, weight-shifting and obstacle crossing.

Approximately 1.2 million people in the United States live with HIV infection. Medical advancements have increased the life expectancy and this cohort is ...

Induction and Assessment of Exertional Skeletal Muscle Damage in Humans

Contraction-induced muscle damage via voluntary eccentric (lengthening) contractions offers an excellent model for studying muscle adaptation and recovery in humans. Herein we discuss the design of an eccentric exercise protocol to induce damage in the quadriceps muscles, marked by changes in strength, soreness, and plasma creatine kinase levels. This method is simple, ethical, and widely applicable since it is performed in human participants and eliminates the interspecies translation of the results. Subjects perform 300 maximal eccentric contractions of the knee extensor muscles at a speed of 120&#176;/sec on an isokinetic dynamometer. The extent of the damage is measurable using relatively non-invasive isokinetic and isometric measures of strength loss, soreness, and plasma creatine kinase levels over several days following the exercise. Therefore, its application can be directed to specific populations in an attempt to identify mechanisms for muscle adaptation and regeneration.

This article describes a safe and reliable method to induce and quantify exertional skeletal muscle damage in human subjects.

Contraction-induced muscle damage via voluntary eccentric (lengthening) contractions offers an excellent model for studying muscle adaptation and recovery ...

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 ...