Supported by NIH grant # R01HL088045. Drs. Eddy Fan and Michelle Kho are each supported by a Fellowship Award from the Canadian Institutes of Health Research.

1. Introduction 
During manual muscle testing (MMT), each muscle group is tested bilaterally. For demonstration purposes, only one side is tested in this video for each of the 6 muscle groups. One hand of the examiner applies resistance or palpates the muscle or tendon for contraction while the other hand stabilizes the extremity being tested to keep it in the test position. The test is repeated if the patient does not understand the instructions or is not applying maximum effort.
2. Grading follows the Medical Research Council (MRC) system (Table 1).1 
Figure 1 illustrates an algorithm for the MRC muscle strength scoring system. If the subject is missing a limb, has a cast, or is unable to be placed in the correct testing position, muscle strength is graded as "unable to assess". If the patient has a fixed contracture, but can otherwise perform the test, the muscle is graded. Medical devices, such as catheters and drains, and mechanical ventilation usually do not impede muscle testing, unless a joint is immobilized to ensure proper functioning of a device.
<img src="/files/ftp_upload/2632/2632fig1.jpg" alt="Figure 1"/> 
Figure 1. Manual Muscle Testing Algorithm
3. Procedure
<ol>
	<li>For each muscle tested, the examiner stands to the side being tested, and the patient is sitting upright and positioned to allow full movement of the joint against gravity. The examiner demonstrates the desired movement against gravity. The examiner then requests the patient to repeat the motion. </li>
	<li>If the patient can move through the desired range of motion against gravity, the examiner attempts to apply resistance in the testing position while stating "Hold it, don't let me push it down" or "Hold it, don't let me bend it" (Figure 2). If the patient tolerates no resistance, the muscle score is Grade 3. If the patient tolerates some resistance, the score is Grade 4, and full resistance, Grade 5. </li>
<li>If the patient cannot move against gravity, the patient is repositioned to allow movement of the extremity with gravity eliminated. If supporting the limb, the examiner provides neither assistance nor resistance to the patient's voluntary movement. This gravity-eliminated positioning will vary for each muscle tested. If the patient cannot complete at least partial range of motion with gravity eliminated, the muscle or tendon is observed and/or palpated for contraction.</li> 
<li>For a bedridden patient who cannot sit up in a bed placed in the chair position or on the edge of the bed, alternate positions for testing the lower extremity are included in this protocol.</li>
</ol>
4. Shoulder Abduction
<ol>
	<li>Testing position - arm out from the side at shoulder level. The examiner demonstrates the motion, then states "Lift your arm out to the side to shoulder level." The hand giving resistance is contoured over the patient's arm just above the elbow. The other hand stabilizes the shoulder above the shoulder joint. The examiner states "Hold it, don't let me push it down." To assess grades 3, 4, or 5, please see section 3.2 above.</li>
<li>If weaker than Grade 3, the patient lies supine with arms at the side. The examiner supports the arm just above the elbow and at the wrist to assure that the shoulder does not externally rotate (turn outward). The patient attempts to move the arm out to the side. The examiner states: "Try to move your arm out to the side". Grade 2 is assigned if the patient moves with gravity eliminated.</li> 
<li>If weaker than Grade 2, the examiner states " Try to move your arm out to the side " and palpates the middle deltoid muscle, as demonstrated, for contraction, and scores as Grade 1 or 0 as previously defined.</li>
<li>Shoulder MMT can be performed with central venous catheters (e.g., subclavian and jugular) in place, including those used for dialysis. (Figure 2)</li>
</ol>
The remaining assessments will be completed similarly to above using specific test positions for the patient and examiner, and specific instructions for the patient's movement.

5. Elbow Flexion
<ol>
<li>Test position - forearm supinated and flexed slightly more than 90 degrees. Verbal instructions: "Bend your elbow slightly more than 90 degrees". The hand giving resistance is contoured over the flexor surface of the forearm proximal to the wrist. The examiner's other hand applies counterforce by cupping the palm over the anterior superior aspect of the shoulder. The examiner then states: "Hold it. Don't let me push it down" and scores Grades 3, 4, or 5 as previously described.</li> 
<li>If weaker than Grade 3, the shoulder is abducted to 90 degrees. The examiner supports the arm under the elbow and, if necessary, the wrist as well. The forearm is turned with the thumb facing the ceiling. With the elbow extended, the patient attempts to flex the elbow. The examiner states: "Try to bend your elbow." Grade 2 is assigned if the patient can flex the elbow.</li> 
<li>If weaker than Grade 2, the forearm is supinated and positioned at the side in approximately 45 degrees of elbow flexion. The examiner states "Try to bend your elbow", palpates the biceps tendon and scores as either Grade 1 or 0.</li> 
</ol>
6. Wrist Extension
<ol>
<li>Test position - arm at the side, elbow flexed to 90 degrees with the forearm pronated and the wrist fully extended. Verbal instructions: "Bend your wrist up as far as possible." The examiner's hand giving resistance is placed over the back of the patient's hand just distal to the wrist. The examiner's other hand supports the patient's forearm. The examiner then states: "Hold it. Don't let me push it down" and scores Grades 3, 4 or 5.</li> 
<li>If weaker than Grade 3, the elbow is flexed to 90 degrees and forearm turned with thumb facing the ceiling. The forearm and wrist are supported by the examiner. The examiner states: "Bend your hand toward me". Grade 2 is assigned if the patient can extend the wrist.</li> 
<li>If weaker than Grade 2, the examiner states "Bend your wrist toward me" and palpates the two extensor tendons, one on each side of the wrist, as demonstrated, and scores as Grade 1 or 0. The examiner is careful not to palpate the tendons in the middle of the wrist.</li>
<li>This test is not performed if there is an ipsilateral radial arterial catheter in place.</li>
</ol>
7. Hip Flexion
<ol>
<li>Test position - sitting with the hip fully flexed and knee bent. The patient may place their hands on the bed or table for stability. Verbal instructions: "Raise your knee up as high as it will go." The examiner's hand giving resistance is placed on top of the thigh just proximal to the knee. The other hand provides stability at the side of the hip. The examiner then states: "Hold it. Don't let me push it down" and scores Grades 3, 4 or 5.</li>
<li>If weaker than Grade 3, the patient lays down on the side not being tested. For example, the patient lays on the right side to test the left hip. The examiner stands behind the patient with one arm cradling the leg being tested with the hand supporting under the knee. The opposite hand maintains alignment of the trunk at the hip. The examiner states:"Bring your knee toward your chest." Grade 2 is assigned if the patient can flex the hip.</li>
<li>If weaker than Grade 2, the patient is supine. The examiner asks, "May I touch your leg here?" (pointing to the inner aspect of the hip joint). With the patient's permission, the examiner states "Bend your hip" and palpates the iliopsoas tendon, as demonstrated, and scores as Grade 1 or 0.</li>
<li>In a bedridden patient, grades 5, 4, and 3 are tested with the bed in the chair position, or the head of the bed elevated as far as possible. Pillows are placed under the knee to flex the hip to 90 degrees. The examiner assures that the foot is lifted off the bed when asking the patient to raise the knee off the bed. Grades 2 and 1 are scored as previously described. </li>
<li>This test can be performed in patients with intact and well secured femoral intravascular catheters.</li>
</ol>
8. Knee Extension
<ol>
	<li>Test position - sitting upright with the knee fully extended to 0 degrees. Avoid knee hyperextension. Verbal instructions; "Straighten your knee". The hand giving resistance is contoured on top of the leg just proximal to the ankle. The other hand is placed under the thigh above the knee. The examiner then states "Hold it. Don't let me bend it" and scores Grades 3, 4 or 5.</li>
<li>If weaker than Grade 3, the patient lays on the non-testing side. The examiner stands behind the patient at knee level. The leg not being tested may be flexed for stability. One arm cradles the leg being tested around the thigh with the hand supporting the underside of the knee. The other hand holds the leg just above the ankle. The examiner states: "Straighten your knee." Grade 2 is assigned if the patient can extend the knee (Figure 3). </li>
<li>If weaker than Grade 2, the patient is supine and the examiner states:"Push the back of your knee down" or "Tighten your knee cap" and palpates the quadriceps tendon, and scores as Grade 1 or 0.</li>
<li>For the bedridden patient, in scoring Grades 3, 4,and 5, the patient is positioned in the same manner as for hip flexion and graded as described above for knee extension (Figure 4).</li>
</ol>
9. Ankle Dorsiflexion
<ol>
	<li>Test position - sitting, with the heel on floor, foot in full dorsiflexion, and shoes and socks removed. Verbal instructions: "Bend your foot up as far as possible." The toes are relaxed during the test. The hand giving resistance is cupped over the top of the foot proximal to the toes. The other hand is contoured around the front of the leg just proximal to the ankle. The examiner then states "Hold it, don't let me push it down" and scores Grade 3, 4 or 5. </li>
<li>If weaker than Grade 3, but there is partial range of motion against gravity, assign Grade 2.</li> 
<li>If weaker than Grade 2, palpate the tibialis anterior tendon, and score as Grade 1or 0.</li>
<li>The bedridden patient is tested supine, with the leg extended and a pillow placed under the knee.</li> 
<li>This test can usually be applied with an intact and secured pedal intravascular catheter. Be careful not to dislodge the catheter.</li>
</ol>
10. Representative Results: 
MMT using this protocol has excellent inter-rater reliability when applied with both ARDS survivors and simulated patents. Quality assurance of 19 trainees examining 12 muscle groups demonstrated an intraclass correlation coefficient (95% confidence interval [CI]) of 0.99 (0.97-1.00).8 Agreement (kappa; 95% CI) for detecting clinically significant weakness (i.e., composite MRC score &lt;80% of maximum) was 1.00 (0.55-1.00). Previous studies have shown high inter-rater reliability with stroke, amyotrophic lateral sclerosis (ALS), Guillain-Barre, and other critically ill patients.12-14 

<img src="/files/ftp_upload/2632/2632fig2.jpg" alt="Figure 2"/> 
Figure 2. ICU patient with a left shoulder abduction contracture. MMT with a left radial arterial line, cardiac monitoring, and continuous dialysis through a right internal jugular catheter. The patient is positioned for shoulder abduction MMT Grades 3, 4 and 5.
<img src="/files/ftp_upload/2632/2632fig3.jpg" alt="Figure 3"/>
 Figure 3. ICU bedridden patient with a right internal jugular catheter for continuous dialysis. The patient is positioned on the right side for knee extension MMT Grade 2. 
<img src="/files/ftp_upload/2632/2632fig4.jpg" alt="Figure 4"/> Figure 4. ICU bedridden patient with a left knee flexion contracture. The patient is positioned supine with a pillow under the knee for knee extension MMT Grades 3, 4 and 5. 


<table border="1">
	<tbody>
 	<tr>
 	<td colspan="2">Table 1. Manual Muscle Test 3</td>
 </tr>
 <tr>
 	<td>Grade </td>
 <td>Manual Muscle Test </td>
 </tr>
 <tr>
 	<td>5</td>
 <td>Movement against gravity plus full resistance</td>
 </tr>
 <tr>
 	<td>4</td>
 <td>Movement against gravity plus some resistance</td>
 </tr>
 <tr>
 	<td>3</td>
 <td>Completes the available test range of motion against gravity, but tolerates no resistance</td>
 </tr>
 <tr>
 	<td>2</td>
 <td>The patient completes full or partial range of motion with gravity eliminated</td>
 </tr>
 <tr>
 	<td>1</td>
 <td>Slight contractility without any movement </td>
 </tr>
 
 <tr>
 	<td>0</td>
 <td>No evidence of contractility (complete paralysis)</td>
 </tr>
 
 
 </tbody>

</table>

<ol>
	<li>De Jonghe, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Paresis+acquired+in+the+intensive+care+unit:+a+prospective+multicenter+study.">Paresis acquired in the intensive care unit: a prospective multicenter study.</a> JAMA. 288, 2859-2867 (2002).</li><li>Ali, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acquired+weakness,+handgrip+strength,+and+mortality+in+critically+ill+patients.">Acquired weakness, handgrip strength, and mortality in critically ill patients.</a> Am J Respir Crit Care Med. 178, 261-268 (2008).</li><li>Angel, M. J., Bril, V., Shannon, P., Herridge, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuromuscular+function+in+survivors+of+the+acute+respiratory+distress+syndrome.">Neuromuscular function in survivors of the acute respiratory distress syndrome.</a> Can. J. Neurol. Sci. 34, 427-432 (2007).</li><li>Cheung, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-year+outcomes,+health+care+use,+and+costs+of+survivors+of+acute+respiratory+distress+syndrome.">Two-year outcomes, health care use, and costs of survivors of acute respiratory distress syndrome.</a> Am. J. Respir. Crit. Care Med. 174, 538-544 (2006).</li><li>Stevens, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuromuscular+dysfunction+acquired+in+critical+illness:+a+systematic+review.+Intensive+Care+Med.">Neuromuscular dysfunction acquired in critical illness: a systematic review. Intensive Care Med.</a> 33, 1876-1891 (2007).</li><li>Herridge, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-year+outcomes+in+survivors+of+the+acute+respiratory+distress+syndrome.">One-year outcomes in survivors of the acute respiratory distress syndrome.</a> N. Engl. J. Med. 348, 683-693 (2003).</li><li>Medical Research Council. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Aids to the Investigation of the Peripheral Nervous System. , (1976).</li><li>Fan, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inter-rater+reliability+of+manual+muscle+strength+testing+in+ICU+survivors+and+simulated+patients.">Inter-rater reliability of manual muscle strength testing in ICU survivors and simulated patients.</a> Intensive Care Med. 34, 1038-1043 (2010).</li><li>Hislop, H. J., Montgomery, 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=.">.</a> Daniels and Worthingham's Muscle Testing. , (2007).</li><li>Reese, N. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Muscle and Sensory Testing. , (2005).</li><li>Kendall, F. P. <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; Testing and Function with Posture and Pain. , (2005).</li><li>Lieu, B. K., Hough, C. L. <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+Weakness+in+Critically+Ill+Patients+Using+Physical+Examination.">Assessment of Weakness in Critically Ill Patients Using Physical Examination.</a> Am J Respir Crit Care Med. 175, A218-A218 (2007).</li><li>Gregson, 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=Reliability+of+measurements+of+muscle+tone+and+muscle+power+in+stroke+patients.">Reliability of measurements of muscle tone and muscle power in stroke patients.</a> Age Ageing. 29, 223-228 (2000).</li><li>Great Lakes ALS Study Group. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.+A+comparison+of+muscle+strength+testing+techniques+in+amyotrophic+lateral+sclerosis.">. A comparison of muscle strength testing techniques in amyotrophic lateral sclerosis.</a> Neurology. 61, 1503-1507 (2003).</li><li>Kleyweg, R. P., van der Meche, F. G., Schmitz, P. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interobserver+agreement+in+the+assessment+of+muscle+strength+and+functional+abilities+in+Guillain-Barre+syndrome.">Interobserver agreement in the assessment of muscle strength and functional abilities in Guillain-Barre syndrome.</a> Muscle Nerve. 14, 1103-1109 (1991).</li><li>Zink, W., Kollmar, R., Schwab, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Critical+illness+polyneuropathy+and+myopathy+in+the+intensive+care+unit.">Critical illness polyneuropathy and myopathy in the intensive care unit.</a> Nat. Rev. Neurol. 5, 372-379 (2009).</li><li>Sharshar, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presence+and+severity+of+intensive+care+unit-acquired+paresis+at+time+of+awakening+are+associated+with+increased+intensive+care+unit+and+hospital+mortality.">Presence and severity of intensive care unit-acquired paresis at time of awakening are associated with increased intensive care unit and hospital mortality.</a> Crit. Care Med. 37, 3047-3053 (2009).</li><li>Griffiths, R. D., Hall, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intensive+care+unit-acquired+weakness.">Intensive care unit-acquired weakness.</a> Crit. Care Med. 38, 779-787 (2010).</li><li>Bohannon, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+knee+extensor+muscle+strength.">Measuring knee extensor muscle strength.</a> Am J Phys Med Rehabil. 80, 13-18 (2001).</li><li>Needham, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mobilizing+patients+in+the+intensive+care+unit:+improving+neuromuscular+weakness+and+physical+function.">Mobilizing patients in the intensive care unit: improving neuromuscular weakness and physical function.</a> JAMA. 300, 1685-1690 (2008).</li></ol>

No conflicts of interest declared.

Depending on the diagnostic criteria, 9 &#x2013; 87% of ICU patients develop neuromuscular complications, which are associated with prolonged mechanical ventilation, increased hospital stay and rehabilitation time, and potentially associated with increased mortality.1,2,16-18 Periodic reassessment of muscle strength, using a reliable method which minimizes inter-rater variability is helpful to detect changes over time. An important limitation of MMT using the MRC score system is the 6-point ordinal scale. M...

manual muscle testing:  a method of measuring extremity muscle strength applied to critically ill patients

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge.1-6 Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. 7, 8 
This video demonstrates a protocol for MMT, which has been taught to &ge;43 research staff who have performed &gt;800 assessments on &gt;280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale.7,9-11 Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. 1,2.

Watch this Scientific Journal Video about Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients at JoVE.com

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, ...

manual-muscle-testing-method-measuring-extremity-muscle-strength

Research

JoVE Journal

Medicine

80.4K Views.  Johns Hopkins University. Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

Video: Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Measuring the Strength of Mice

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score maximum on this task; it is a quick but insensitive gross screen, and the weights test described in this article will provide a finer measure of muscular strength.
There are also several strain gauge-based pieces of apparatus available commercially that will provide more graded data than the inverted screen test, but their cost may put them beyond the reach of many laboratories which do not specialize in strength testing. Hence in 2000 a cheap and simple apparatus was devised by the author. It consists of a series of chain links of increasing length, attached to a "fur collector" a ball of fine wire mesh sold for preventing limescale build up in hard water areas. An accidental observation revealed that mice could grip these very tightly, so they proved ideal as a grip point for a weight-lifting apparatus. A common fault with commercial strength meters is that the bar or other grip feature is not thin enough for mice to exert a maximum grip. As a general rule, the thinner the wire or bar, the better a mouse can grip with its small claws.
This is a pure test of strength, although as for any test motivational factors could potentially play a role. The use of scale collectors, however, seems to minimize motivational problems as the motivation appears to be very high for most normal young adult mice.

Deficits in muscular strength occur in many clinical conditions such as motor neuron disease. The inverted screen and weight lifting tests described here measure strength in mice almost exclusively, with minimal influence of factors such as coordination.

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score ...

Method to Measure Tone of Axial and Proximal Muscle

The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs1, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention.

We have developed a device (Twister) to study the regulation of tonic muscle activity during active postural maintenance. Twister measures torsional resistance and muscular responses in standing subjects during twisting of the body axis. The device can be flexibly configured to study various aspects of tonic control across the neck, trunk, and/or hips.

The control of tonic muscular activity remains poorly understood.  While abnormal tone is commonly assessed clinically by measuring the passive resistance ...

High-throughput Flow Cytometry Cell-based Assay to Detect Antibodies to N-Methyl-D-aspartate Receptor or Dopamine-2 Receptor in Human Serum

Over the recent years, antibodies against surface and conformational proteins involved in neurotransmission have been detected in autoimmune CNS diseases in children and adults. These antibodies have been used to guide diagnosis and treatment. Cell-based assays have improved the detection of antibodies in patient serum. They are based on the surface expression of brain antigens on eukaryotic cells, which are then incubated with diluted patient sera followed by fluorochrome-conjugated secondary antibodies. After washing, secondary antibody binding is then analyzed by flow cytometry. Our group has developed a high-throughput flow cytometry live cell-based assay to reliably detect antibodies against specific neurotransmitter receptors. This flow cytometry method is straight forward, quantitative, efficient, and the use of a high-throughput sampler system allows for large patient cohorts to be easily assayed in a short space of time. Additionally, this cell-based assay can be easily adapted to detect antibodies to many different antigenic targets, both from the central nervous system and periphery. Discovering additional novel antibody biomarkers will enable prompt and accurate diagnosis and improve treatment of immune-mediated disorders.

Over the recent years, live cell-based assays have been used successfully to detect antibodies against surface and conformational antigens. Here, we describe a method using high-throughput flow cytometry enabling the analysis of large cohorts of patients. Detection of novel antibodies will improve diagnosis and treatment of immune-mediated disorders.

Over the recent years, antibodies against surface and conformational proteins involved in neurotransmission have been detected in autoimmune CNS diseases ...

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology

We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties of the smooth muscle as well as changes induced by pathology. This method provides critical information for understanding bladder function while overcoming major methodological difficulties encountered in in vivo experiments, such as surgical and pharmacological manipulations that affect stability and survival of the preparations, the use of human tissue, and/or the use of expensive chemicals. It also provides a way to investigate the properties of each bladder component (i.e. smooth muscle, mucosa, nerves) in healthy and pathological conditions.
The urinary bladder is removed from an anesthetized animal, placed in Krebs solution and cut into strips. Strips are placed into a chamber filled with warm Krebs solution. One end is attached to an isometric tension transducer to measure contraction force, the other end is attached to a fixed rod. Tissue is stimulated by directly adding compounds to the bath or by electric field stimulation electrodes that activate nerves, similar to triggering bladder contractions in vivo. We demonstrate the use of this method to evaluate spontaneous smooth muscle contractility during development and after an experimental spinal cord injury, the nature of neurotransmission (transmitters and receptors involved), factors involved in modulation of smooth muscle activity, the role of individual bladder components, and species and organ differences in response to pharmacological agents. Additionally, it could be used for investigating intracellular pathways involved in contraction and/or relaxation of the smooth muscle, drug structure-activity relationships and evaluation of transmitter release.
The in vitro smooth muscle contractility method has been used extensively for over 50 years, and has provided data that significantly contributed to our understanding of bladder function as well as to pharmaceutical development of compounds currently used clinically for bladder management.

This manuscript presents a simple, yet powerful, in vitro method for evaluating smooth muscle contractility in response to pharmacological agents or nerve stimulation. Main applications are drug screening and understanding tissue physiology, pharmacology,&#160;and pathology.

We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties ...

Early Detection of Drug-Induced Renal Hemodynamic Dysfunction Using Sonographic Technology in Rats

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is estimated to contribute to 19- 25% of all clinical cases of acute kidney injury (AKI) in critically ill patients. AKI detection has historically relied on metrics such as serum creatinine (sCr) or blood urea nitrogen (BUN) which are demonstrably inadequate in full assessment of nephrotoxicity in the early phase of renal dysfunction. Currently, there is no robust diagnostic method to accurately detect hemodynamic alteration in the early phase of AKI while such alterations might actually precede the rise in serum biomarker levels. Such early detection can help clinicians make an accurate diagnosis and help in in decision making for therapeutic strategy. Rats were treated with Cisplatin to induce AKI. Nephrotoxicity was assessed for six days using high-frequency sonography, sCr measurement and upon histopathology of kidney. Hemodynamic evaluation using 2D and Color-Doppler images were used to serially study nephrotoxicity in rats, using the sonography. Our data showed successful drug-induced kidney injury in adult rats by histological examination. Color-Doppler based sonographic assessment of AKI indicated that resistive-index (RI) and pulsatile-index (PI) were increased in the treatment group; and peak-systolic velocity (mm/s), end-diastolic velocity (mm/s) and velocity-time integral (VTI, mm) were decreased in renal arteries in the same group. Importantly, these hemodynamic changes evaluated by sonography preceded the rise of sCr levels. Sonography-based indices such as RI or PI can thus be useful predictive markers of declining renal function in rodents. From our sonography-based observations in the kidneys of rats that underwent AKI, we showed that these noninvasive hemodynamic measurements may consider as an accurate, sensitive and robust method in detecting early stage kidney dysfunction. This study also underscores the importance of ethical issues associated with animal use in research.

Early stage hemodynamic dysfunction is critical to the development of kidney disease. Yet, detection methodologies are limited. Recent advances in sonography provide a noninvasive, accurate option for early detection of kidney injury. This study outlines a step-by-step, sonographic methodology for detecting kidney dysfunction using a drug-induced nephrotoxicity rat model.

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is ...

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 ...

Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload

Children with sickle cell anemia (SCA) may be at risk of cerebral vasculopathy and strokes, which can be prevented by chronic transfusion programs. Repeated transfusions of packed red blood cells (PRBCs) is currently the simplest and most used technique for chronic transfusion programs. However, iron overload is one of the major side effects of this therapy. More developed methods exist, notably the apheresis of RBC (erythrapheresis), which is currently the safest and most efficient method. However, it is costly, complicated, and cannot be implemented everywhere, nor is it suitable for all patients. Manual exchange transfusions combine one or more manual phlebotomies with a PRBC transfusion.
At the Reference Center of Sickle Cell Disease, we set up a continuous method of manual exchange transfusion that is feasible for all hospital settings, demands no specific equipment, and is widely applicable. In terms of HbS decrease, stroke prevention, and iron overload prevention, this method showed comparable efficiency to erythrapheresis. In cases where erythrapheresis is not available, this method can be a good alternative for patients and care centers.

We have outlined a method of continuous manual exchange transfusion for the treatment of sickle cell disease in patients. This safe protocol was designed to effectively limit iron overload in patients in need of chronic transfusions and can be used extensively without any special equipment.

Children with sickle cell anemia (SCA) may be at risk of cerebral vasculopathy and strokes, which can be prevented by chronic transfusion programs. ...

Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in elderly people performing short-term resistance training (RET). Supervised progressive resistance training for 1 h three times a week over 8 weeks was performed by RET participants (71&#177;1 years, range 65-80). Compared to a control group without training, the RET showed improvements on the measures used to indicate strength, power, glucose tolerance, and several parameters of muscle aerobic capacity. Strength training was performed in a gym with only robust fitness equipment. An isokinetic dynamometer for knee extensor strength permitted the measurement of concentric, eccentric, and static strength, which increased for the RET group (8-12% post- versus pre-test). The power (rate of force development, RFD) at the initial 0-30 ms also showed an increase for the RET group (52%). A glucose tolerance test with frequent blood glucose measurements showed improvements only for the RET group in terms of blood glucose values after 2 h (14%) and the area under the curve (21%). The blood lipid profile also improved (8%). From muscle biopsy samples prepared using histochemistry, the amount of fiber type IIa increased, and a trend towards a decrease in IIx in the RET group reflected a change to a more oxidative profile in terms of fiber composition. Western blot (to determine the protein content related to the signaling for muscle protein synthesis) showed a rise of 69% in both Akt and mTOR in the RET group; this also showed an increase in mitochondrial proteins for OXPHOS complex II and citrate synthase (both ~30%) and for complex IV (90%), in only the RET group. We demonstrate that this type of progressive resistance training offers various improvements (e.g., strength, power, aerobic capacity, glucose tolerance, and plasma lipid profile).

The effect of short-term resistance training on elderly people was investigated through the simultaneous use of several methods. Compared to a control group, many improvements were seen, including on muscle aerobic capacity, glucose tolerance, strength, power, and muscle quality (i.e., protein involved in cell signaling and muscle fiber type composition).

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in ...

In Vivo Evaluation of the Mechanical and Viscoelastic Properties of the Rat Tongue

The tongue is a highly innervated and vascularized muscle hydrostat on the floor of the mouth of most vertebrates. Its primary functions include supporting mastication and deglutition, as well as taste-sensing and phonetics. Accordingly, the strength and volume of the tongue can impact the ability of vertebrates to accomplish basic activities such as feeding, communicating, and breathing. Human patients with sleep apnea have enlarged tongues, characterized by reduced muscle tone and increased intramuscular fat that can be visualized and quantified by magnetic resonance imaging (MRI). The abilities to measure force generation and viscoelastic properties of the tongue constitute important tools for obtaining functional information to correlate with imaging data. Here, we present techniques for measuring tongue force production in anesthetized Zucker rats via electrical stimulation of the hypoglossal nerves and for determining the viscoelastic properties of the tongue by applying passive Lissajous force/deformation curves.

In Vivo Evaluation of the Mechanical and Viscoelastic Properties of the Rat Tongue

We describe a surgical procedure in an anesthetized rat model for determining the muscle tone and viscoelastic properties of the tongue. The procedure involves specific stimulation of the hypoglossal nerves and application of passive Lissajous force/deformation curves to the muscle.

The tongue is a highly innervated and vascularized muscle hydrostat on the floor of the mouth of most vertebrates. Its primary functions include ...

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations

Many hamstring injuries that occur during physical activity occur while the muscles are lengthening, during eccentric hamstring muscle actions. Opposite of these eccentric hamstring actions are concentric quadriceps actions, where the larger and likely stronger quadriceps straighten the knee. Therefore, to stabilize the lower limbs during movement, the hamstrings must eccentrically combat against the strong knee-straightening torque of the quadriceps. As such, eccentric hamstring strength expressed relative to concentric quadricep strength is commonly referred to as the &#34;functional ratio&#34; as most movements in sports require simultaneous concentric knee extension and eccentric knee flexion. To increase the strength, resiliency, and functional performance of the hamstrings, it is necessary to test and train the hamstrings at different eccentric speeds. The main purpose of this work is to provide instructions for measuring and interpreting eccentric hamstring strength. Techniques for measuring the functional ratio using isokinetic dynamometry are provided and sample data will be compared. Additionally, we briefly describe how to address hamstring strength deficiencies or unilateral strength differences using exercises that specifically focus on increasing eccentric hamstring strength.

The hamstrings are a group of muscles that are sometimes problematic for athletes, resulting in soft tissue injury in the lower limbs. To prevent such injuries, functional training of the hamstrings requires intensive eccentric contractions. Additionally, hamstring function should be tested in relation to quadricep function at different contraction speeds.

Many hamstring injuries that occur during physical activity occur while the muscles are lengthening, during eccentric hamstring muscle actions. Opposite ...