Name: sit-to-stand-and-walk from 120% knee height: a novel approach to assess dynamic postural control independent of lead-limb
Uploaded: 2016-08-30T14:00:00
Description: Watch this Scientific Journal Video about Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb at JoVE.com

The authors would like to thank Tony Christopher, Lindsey Marjoram at King&#39;s College London and Bill Anderson at London South Bank University for their practical support. Thank you also to Eleanor Jones at King&#39;s College London for her help in collecting the data for this project.

The protocol follows the local guidelines for the testing of human participants, defined by London South Bank University research ethics committee approval (UREC1413/2014).
1. Gait Laboratory Preparation
<ol>
	<li>Clear the capture volume of unwanted reflective objects that may be misinterpreted as movement markers and eliminate ambient daylight to reduce reflections as appropriate.</li>
	<li>Turn on motion-capture cameras, proprietary tracking software, force platform amplifiers, and extern...

<ol>
	<li>Duncan, P. W., Goldstein, L. B., Matchar, D., Divine, G. W., Feussner, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+motor+recovery+after+stroke.+Outcome+assessment+and+sample+size+requirements.">Measurement of motor recovery after stroke. Outcome assessment and sample size requirements.</a> Stroke. 23 (8), 1084-1089 (1992).</li><li>Smith, M. T., Baer, G. 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A systematic review and meta-analysis.</a> PLoS One. 9 (2), e87987 (2014).</li><li>Magnan, A., McFadyen, B., St-Vincent, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modification+of+the+sit-to-stand+task+with+the+addition+of+gait+initiation.">Modification of the sit-to-stand task with the addition of gait initiation.</a> Gait Posture. 4 (3), 232-241 (1996).</li><li>Buckley, T. A., Pitsikoulis, C., Hass, 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=Dynamic+postural+stability+during+sit-to-walk+transitions+in+Parkinson+disease+patients.">Dynamic postural stability during sit-to-walk transitions in Parkinson disease patients.</a> Mov Disord. 23 (9), 1274-1280 (2008).</li><li>Frykberg, G. E., Aberg, A. 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A., Cosgrove, A., Baker, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparing+methods+of+estimating+the+total+body+centre+of+mass+in+three-dimensions+in+normal+and+pathological+gaits.">Comparing methods of estimating the total body centre of mass in three-dimensions in normal and pathological gaits.</a> Human movement science. 18 (5), 637-646 (1999).</li><li>C-Motion Wiki Documentation. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Force Structures. , (2015).</li><li>Martin, 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=Gait+initiation+in+community-dwelling+adults+with+Parkinson+disease:+comparison+with+older+and+younger+adults+without+the+disease.">Gait initiation in community-dwelling adults with Parkinson disease: comparison with older and younger adults without the disease.</a> Phys Ther. 82 (6), 566-577 (2002).</li><li>Bland, J. M., Altman, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+error.">Measurement error.</a> BMJ. 313 (7059), (1996).</li><li>Hof, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scaling+gait+data+to+body+size.">Scaling gait data to body size.</a> Gait Posture. 4 (3), 222-223 (1996).</li><li>Holden, J. P., Selbie, W. S., Stanhope, S. 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+proposed+test+to+support+the+clinical+movement+analysis+laboratory+accreditation+process.">A proposed test to support the clinical movement analysis laboratory accreditation process.</a> Gait Posture. 17 (3), 205-213 (2003).</li><li>Baker, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gait+analysis+methods+in+rehabilitation.">Gait analysis methods in rehabilitation.</a> J Neuroeng Rehabil. 3, (2006).</li><li>Gregory, C. M., Embry, A., Perry, L., Bowden, M. 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The sit-to-stand-and-walk (STSW) protocol defined here can be used to test dynamic postural control during complex transitional movement in healthy individuals or patient groups. The protocol includes constraints that are designed to allow subjects with pathology to participate, and the inclusion of switching off the light means it is ecologically valid and goal-orientated. As it has been shown previously that lead-limb and rising from a high (120% KH) seat does not fundamentally affect task dynamics during STSW20</...

Clinical pathologies affecting the sensorimotor systems, for example upper motor neuron (UMN) injury following stroke, lead to functional impairments including weakness, loss of postural stability and spasticity, which can negatively affect locomotion. Recovery can be variable with a significant number of stroke survivors failing to achieve the functional milestones of safe standing or walking1,2.
The discrete practice of walking and sit-to-stand are common rehabilitative tasks after UMN pathology3,4, however transitional movements are frequently neglected. Sit-to-walk (STW) is a sequential postural-locomotor task incorporating sit-to-stand (STS), gait initiation (GI), and walking5.
Separation of STS and GI, reflective of hesitation during STW has been observed in patients with Parkinson&#39;s disease6 and chronic stroke7, in addition to older unimpaired adults8, but not in young healthy individuals9. Therefore sit-to-stand-and-walk (STSW) is commonly implemented within the clinical environment and is defined by a pause phase of variable length when standing. However, there are no published protocols to date defining STSW dynamics in a context suitable for patient populations.
Usually in STW studies the initial chair height is 100% of knee height (KH; floor-to-knee distance), foot-width and GI lead-limb are self-selected, arms are constrained across the chest and an ecologically meaningful task context is often absent5-9. However, patients find rising from 100% KH challenging10 and frequently adopt a wider foot position compared with healthy individuals11, initiate gait with their affected leg7, and use their arms to generate momentum7.
To initiate gait, a state change in whole-body movement in a purposeful direction is required12. This is achieved by uncoupling the whole-body center-of-mass (BCOM: the weighted average of all considered body segments in space13) from the center-of-pressure (COP: the position of the resultant ground reaction force (GRF) vector14). In the anticipatory phase of GI, rapid stereotypical posterior and lateral movement of the COP toward the limb to be swung occurs thereby generating BCOM momentum12,15. The COP and BCOM are thus separated, with the horizontal distance between them having been proposed as a measure of dynamic postural control16.
The calculation of COP-BCOM distance requires simultaneous measurement of the COP and BCOM positions. The standard calculation of COP is shown below in equation (1)17:
<img alt="Equation 1" src="/files/ftp_upload/54323/54323eq1.jpg" />
<img alt="Equation 2" src="/files/ftp_upload/54323/54323eq2.jpg" />
<img alt="Equation 3" src="/files/ftp_upload/54323/54323eq3.jpg" /> 
(1)
Where M and Force represent moments about the force platform axes and the directional GRF respectively. The subscripts represent axes. The origin is the vertical distance between the contact surface and the origin of the force platform, and is considered to be zero.
The kinematic method of deriving BCOM position involves tracking the displacement of segmental markers. A faithful representation of body-segment motion can be achieved by employing markers clustered on rigid plates placed away from bony landmarks, minimizing soft-tissue-artifact (CAST technique18). In order to determine BCOM position, individual body segment masses are estimated, based on cadaveric work19. Three-dimensional (3D) motion system proprietary software uses the coordinate positions of proximal and distal segment locations to: 1) determine segmental lengths, 2) arithmetically estimate segmental masses, and 3) compute segmental COM locations. These models are then able to provide estimates of 3D BCOM position at a given point in time based on the net summation of inter-segmental positions (Figure 1).
Thus, the purpose of this paper is first to present a standardized STSW protocol that is ecologically valid and includes rising from a high seat-height. It has been shown previously that STSW from 120% KH is biomechanically indistinct from 100% KH barring generation of lower BCOM vertical velocities and GRF&#39;s during rising20, meaning rising from 120% KH is easier (and safer) for compromised individuals. Second, to derive COP-BCOM horizontal distances to assess dynamic postural control during key milestones and transitions using 3D motion-capture. This approach, which in healthy individuals during STSW is independent of limb-lead20, offers the prospect of functional recovery evaluation. Finally, a preliminary STSW data set representative of young healthy individuals is presented, and intra and inter-subject variability in the group is defined in order to inform comparison with pathological individuals.
<img alt="Figure 1" src="/files/ftp_upload/54323/54323fig1.jpg" /> 
Figure 1. 2D BCOM calculation. For simplicity, the example is based on calculating whole-leg COM from a 3-linked mass in 2 dimensions, where coordinates of the respective COM positions (x,y), and segmental masses (m1, m2, m3) are known. Segment masses and location of segmental COM positions, with respect to the laboratory coordinate system (LCS; origin: 0, 0), are estimated by motion analysis system proprietary software using subject body mass and published anthropometric data (see main text). The x and y leg COM position, in this example of the 3-linked mass, is then derived using the formulae shown. <a href="https://www.jove.com/files/ftp_upload/54323/54323fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="0" cellpadding="0" cellspacing="0" width="1140">
	<tbody>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Motion Tracking Cameras</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td style="width:119px;">Oqus 300+</td>
			<td style="width:659px;">n=8</td>
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		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Qualysis Track Manager (QTM)</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td style="width:119px;">QTM 2.9 Build No: 1697</td>
			<td>Proprietary tracking software&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Force Platform&#160; Amplifier</td>
			<td style="width:147px;">Kistler Instruments, Hook, UK</td>
			<td style="width:119px;">5233A</td>
			<td>n=4</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Force Platform</td>
			<td style="width:147px;">Kistler Instruments, Hook, UK</td>
			<td style="width:119px;">9281E</td>
			<td>n=4</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">AD Converter</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td style="width:119px;">230599</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Light-Weight Wooden Walkway Section</td>
			<td style="width:147px;">Kistler Instruments, Hook, UK</td>
			<td style="width:119px;">Type 9401B01&#160;</td>
			<td>n=2</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Light-Weight Wooden Walkway Section</td>
			<td style="width:147px;">Kistler Instruments, Hook, UK</td>
			<td style="width:119px;">Type 9401B02&#160;</td>
			<td>n=4</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">4 Point &#34;L-Shaped&#34; Calibration Frame</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">&#34;T-Shaped&#34; Wand</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">12mm Diameter Passive Retro reflective Marker</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td>Cat No: 160181</td>
			<td>Flat Base</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Double Adhesive Tape</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td>Cat No: 160188</td>
			<td>For fixing markers to skin</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:216px;">Height-Adjustable Stool</td>
			<td style="width:147px;">Ikea, Sweden</td>
			<td style="width:119px;">Svenerik</td>
			<td>Height 43-58cmwith ~10cm customized height extension option at each leg</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Circular (Disc) Pressure Floor Pad</td>
			<td style="width:147px;">Arun Electronics Ltd, Sussex, UK</td>
			<td style="width:119px;">PM10</td>
			<td>305mm Diameter, 3mm thickness, 2 wire</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Lower Limb Tracking Marker Clusters</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td>Cat No: 160145</td>
			<td>2 Marker clusters, lower body with 8 markers (n=2)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Upper Limb Tracking Marker Clusters</td>
			<td style="width:147px;">Qualysis&#160; (Qualysis AB Gothenburg, Sweden)</td>
			<td>Cat No: 160146</td>
			<td>2 Marker clusters, lower body with 6 markers (n=2)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Self-Securing Bandage</td>
			<td style="width:147px;">Fabrifoam, PA, USA</td>
			<td style="width:119px;"></td>
			<td>3&#39;&#39; x 5&#39;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cycling Skull Cap</td>
			<td style="width:147px;">Dhb</td>
			<td style="width:119px;">Windslam</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Digital Column Scale</td>
			<td style="width:147px;">Seca</td>
			<td style="width:119px;">763 Digital Medical Scale w/ Stadiometer</td>
			<td></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">Measuring Caliper</td>
			<td style="width:147px;">Grip-On</td>
			<td style="width:119px;">Grip Jumbo Aluminum Caliper - Model no. 59070</td>
			<td>24in. Jaw</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Extendable Arm Goniometer</td>
			<td style="width:147px;">Lafayette Instrument</td>
			<td>Model 01135</td>
			<td>Gollehon</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Light Switch</td>
			<td style="width:147px;"></td>
			<td style="width:119px;"></td>
			<td>Custom made</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Visual3D Biomechanics Analysis Software</td>
			<td style="width:147px;">C-Motion Inc., Germantown, MD, USA</td>
			<td style="width:119px;">Version 4.87</td>
			<td></td>
		</tr>
	</tbody>
</table>

sit-to-stand-and-walk from 120% knee height: a novel approach to assess dynamic postural control independent of lead-limb

Individuals with sensorimotor pathology e.g., stroke have difficulty executing the common task of rising from sitting and initiating gait (sit-to-walk: STW). Thus, in clinical rehabilitation separation of sit-to-stand and gait initiation - termed sit-to-stand-and-walk (STSW) - is usual. However, a standardized STSW protocol with a clearly defined analytical approach suitable for pathological assessment has yet to be defined.
Hence, a goal-orientated protocol is defined that is suitable for healthy and compromised individuals by requiring the rising phase to be initiated from 120% knee height with a wide base of support independent of lead limb. Optical capture of three-dimensional (3D) segmental movement trajectories, and force platforms to yield two-dimensional (2D) center-of-pressure (COP) trajectories permit tracking of the horizontal distance between COP and whole-body-center-of-mass (BCOM), the decrease of which increases positional stability but is proposed to represent poor dynamic postural control.
BCOM-COP distance is expressed with and without normalization to subjects&#39; leg length. Whilst COP-BCOM distances vary through STSW, normalized data at the key movement events of seat-off and initial toe-off (TO1) during steps 1 and 2 have low intra and inter subject variability in 5 repeated trials performed by 10 young healthy individuals. Thus, comparing COP-BCOM distance at key events during performance of an STSW paradigm between patients with upper motor neuron injury, or other compromised patient groups, and normative data in young healthy individuals is a novel methodology for evaluation of dynamic postural stability.

All subjects rose with their feet placed on the twin force platforms, leading with their non-dominant limb as instructed. Normal gait was observed with subjects stepping cleanly onto the other platforms and 3D optical-based motion analysis successfully tracked whole body movement during 5 repeated goal-orientated STSW tasks rising from 120% KH. Simultaneous COP and BCOM mediolateral (ML) and anteroposterior (AP) displacements between seat-off and IC2 (100% STSW cycle) comprising: rise, pa...

Watch this Scientific Journal Video about Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb at JoVE.com

Sit-to-stand-and-walk from 120% Knee Height: A Novel Approach to Assess Dynamic Postural Control Independent of Lead-limb

Here, we present a novel protocol to measure positional stability at key events during the sit-to-stand-to-walk using the center-of-pressure to the whole-body-center-of-mass distance. This was derived from the force platform and three-dimensional motion-capture technology. The paradigm is reliable and can be utilized for the assessment of neurologically compromised individuals.

Individuals with sensorimotor pathology e.g., stroke have difficulty executing the common task of rising from sitting and initiating gait (sit-to-walk: ...

The overall goal of this protocol is to measure dynamic positional stability during sit, to stand, and walk. A complex transitional movement that individuals with pathology often find difficult. The main advantages of this technique is that it utilizes the best available center of pressure and whole body center of mass estimations, or COP, BOM, to provide a composite measure of stability.The implications of this technique can also inform clinical practice. As meaningful stability measurements could be deployed to predict recovery and evaluate treatments to effect recovery rates of sitting to walking. Demonstrating the procedure our participant will go through, will be Michael Attwaters, a graduate student from the laboratory.Begin by the opening the proprietary tracking software on the computer. Set the capture frequency to 60 hertz, and set the 3D tracking parameters, which include a prediction error of 20 millimeters, a maximum residual of two millimeters, a minimum trajectory length equivalent to two frames, and a maximum frame gap of 10 frames. Then, identify each of the eight individual force platform components from each form platform amplifier into the respective analogue to digital converter.Ensure all predetermined calibration settings from each force platform, scaling factors, and analogue channels have been specified. Additionally, configure the software to read the baseline force plate reading during the last 10 frames of capture. Select a multiplier of 17 for the motion capture frequency to ensure an adequete analogue sampling frequency of 1020 hertz.In preparation for the calibration of 3D space position the L shaped reference structure on the floor in the capture volume, with the long axis of this structure pointing in the interior direction. Then, within the calibration settings page in the software select wand as the calibration type with a 750 millimeter length. And select coordinate system orientation with the positive C axis pointing upwards and the positive Y axis as the long arm.Click okay. Click the calibration icon and set the intended length of the calibration capture to 60 seconds. Then, identify the file directory where the results will be saved.Click okay to begin calibrating. Move the calibration wand within the capture volume, by rotating and translating the wand around the intended capture volume for 60 seconds. Then, check calibration results and accept calibration with individual camera residual errors of less than 1.5 millimeters.Click okay. Finally, locate the force platforms in the calibrated 3D space by placing one, nine millimeter diameter passive retro reflective marker in each of the four corners of each platform. Obtain a five second recording and identify each platforms reference system and marker within the 3D space.On the subject, use double adhesive tape and self securing bandages to adhere retro reflective markers to anatomical landmarks of the lower and upper extremities, trunk, head, and pelvic segments, in accordance with the chosen technical frame of reference. Then, instruct the subject to stand stationary in there center of the capture volume. Open the propriatory tracking software with the previously set sampling parameters.Within the software, confirm visually that all markers are accounted for. Then, click the record icon to complete a five second static capture. Begin by removing all anatomical markers.To set up the final feed position, ask the subject to sit on the stool with their feet on the individual force platforms, one and two. Adjust the shank position on the subjects dominant side 10 degrees posterior from the vertical using an extendable arm goniometer. Adjust the non-dominant foot equally in line and then use lock calipers to arrange the inter foot width to the predetermined biocromial distance accordingly, between the lateral foot borders.Next, adjust the transverse plane orientation of each foot such, that each medial foot border is placed in line with the direction of travel. Then, use a marker to draw around the final foot positions on the surface of the removable force platform. Within the software, confirm visually that all markers are accounted for, then click the record icon to complete a 15 second dynamic capture.Five seconds into the dynamic capture turn on the operator light switch which notifies the subject to rise from the stool and pause, step on to force platforms three and four, walk toward the light switch, stop, then turn the light switch off with their dominant hand. Finally, reset the light switch and check for marker drop outs by accounting for all markers during slow motion playback of the trial. Within the proprietary tracking software identify and label all the markers from static and dynamic trials, and crop unwanted capture by moving the time slides to the beginning and end of the task.Utilize the automatic identification of markers, or aim functionality to label the markers so that the software consistently constructs and calculates the relative trajectory of a rigid body in 3D space. If a marker dropped out for more than 10 frames locate the missing trajectory in the unidentified trajectories panel. Finally, format and export all static and dynamic trials in C3D format for post-processing and biomechanics analysis software.In the mediolateral plane, the whole body center of mass, or BCOM, follows a sinusoidal displacement after initiation of gait, and the center of pressure, of COP displaces further laterally during single limb stance during steps one and two. In the anteroposterior plane, the COP at seat-off starts in front of the BCOM. And while they both move forward during rising, their separation diminishes steadily before merging at upright.The horizontal separation distance between COP and BCOM during the rise, pause, gait initiation, step one, and step two, shows the complex interaction of COP and BCOM displacement, providing an index of positional stability. Once mastered, this movement capture technique can be completed within a few minutes if it is performed properly, and local post-processing can be systematized to capture positional stability, COP BCOM measures in real time. After watching this video, you should have a good understanding of how to measure dynamic positional stability using COP BCOM distance during sit, to stand, and walk.

sit-to-stand-walk-from-120-knee-height-novel-approach-to-assess

Research

JoVE Journal

Behavior

Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognitive functions across the lifespan in a sample of 378 healthy subjects (age range 18-89 years). Consistent with previous findings we found an age-related cognitive decline across a wide range of neuropsychological domains (memory, attention, executive functions), thereby proving the usability of our tablet-based application. Regardless of prior computer experience, subjects of all age groups were able to perform the tasks without instruction or feedback from an experimenter. Increased motivation and compliance proved to be beneficial for task performance, thereby potentially increasing the validity of the results. Our promising findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.

The main goal of this study was to assess the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on ...

Assessing Forelimb Function after Unilateral Cervical SCI using Novel Tasks: Limb Step-alternation, Postural Instability and Pasta Handling

Cervical spinal cord injury (cSCI) can cause devastating neurological deficits, including impairment or loss of upper limb and hand function. A majority of the spinal cord injuries in humans occur at the cervical levels. Therefore, developing cervical injury models and developing relevant and sensitive behavioral tests is of great importance. Here we describe the use of a newly developed forelimb step-alternation test after cervical spinal cord injury in rats. In addition, we describe two behavioral tests that have not been used after spinal cord injury: a postural instability test (PIT), and a pasta-handling test. All three behavioral tests are highly sensitive to injury and are easy to use. Therefore, we feel that these behavioral tests can be instrumental in investigating therapeutic strategies after cSCI.

Three new behavioral tests (forelimb step-alternation, postural instability test, pasta handling test) for evaluating forelimb function after cervical spinal cord injury in rodents are described.

Cervical spinal cord injury (cSCI) can cause devastating neurological deficits, including impairment or loss of upper limb and hand function. A majority ...

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical components. Both anxiety and fear can be studied in the laboratory by measuring the potentiation of the startle reflex. The startle reflex is a defensive reflex that is potentiated when an organism is threatened and the need for defense is high. The startle reflex is assessed via electromyography (EMG) in the orbicularis oculi muscle elicited by brief, intense, bursts of acoustic white noise (i.e., &#8220;startle probes&#8221;). Startle potentiation is calculated as the increase in startle response magnitude during presentation of sets of visual threat cues that signal delivery of mild electric shock relative to sets of matched cues that signal the absence of shock (no-threat cues). In the Threat Probability Task, fear is measured via startle potentiation to high probability (100% cue-contingent shock; certain) threat cues whereas anxiety is measured via startle potentiation to low probability (20% cue-contingent shock; uncertain) threat cues. Measurement of startle potentiation during the Threat Probability Task provides an objective and easily implemented alternative to assessment of negative affect via self-report or other methods (e.g., neuroimaging) that may be inappropriate or impractical for some researchers. Startle potentiation has been studied rigorously in both animals (e.g., rodents, non-human primates) and humans which facilitates animal-to-human translational research. Startle potentiation during certain and uncertain threat provides an objective measure of negative affective and distinct emotional states (fear, anxiety) to use in research on psychopathology, substance use/abuse and broadly in affective science. As such, it has been used extensively by clinical scientists interested in psychopathology etiology and by affective scientists interested in individual differences in emotion.

Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science.

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical ...

A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants

Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing &#8220;in action and in context&#8221;. This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks.

This protocol presents a novel methodology for the neural decoding of intent from freely-behaving infants during unscripted social interaction with an actor. Neural activity is acquired using non-invasive high-density active scalp electroencephalography (EEG). Kinematic data is collected with inertial measurement units and supplemented with synchronized video recording.

Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental ...

A Novel Approach to Assess Motor Outcome of Deep Brain Stimulation Effects in the Hemiparkinsonian Rat: Staircase and Cylinder Test

Deep brain stimulation of the subthalamic nucleus is an effective treatment option for Parkinson&#39;s disease. In our lab we established a protocol to screen different neurostimulation patterns in hemiparkinsonian (unilateral lesioned) rats. It consists of creating a unilateral Parkinson&#39;s lesion by injecting 6-hydroxydopamine (6-OHDA) into the right medial forebrain bundle, implanting chronic stimulation electrodes into the subthalamic nucleus and evaluating motor outcomes at the end of 24 hr periods of cable-bound external neurostimulation. The stimulation was conducted with constant current stimulation. The amplitude was set 20% below the individual threshold for side effects. The motor outcome evaluation was done by the assessment of spontaneous paw use in the cylinder test according to Shallert and by the assessment of skilled reaching in the staircase test according to Montoya. This protocol describes in detail the training in the staircase box, the cylinder test, as well as the use of both in hemiparkinsonian rats. The use of both tests is necessary, because the staircase test seems to be more sensitive for fine motor skill impairment and exhibits greater sensitivity to change during neurostimulation. The combination of the unilateral Parkinson model and the two behavioral tests allows the assessment of different stimulation parameters in a standardized way.

Deep brain stimulation (DBS) is an effective treatment option for Parkinson's disease. We established a study design to screen novel stimulation paradigms in rats. The protocol describes the use of the staircase test and cylinder test for motor outcome assessment in DBS treated hemiparkinsonian rats.

Deep brain stimulation of the subthalamic nucleus is an effective treatment option for Parkinson&#39;s disease. In our lab we established a protocol to ...

Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to progressive loss of motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. To evaluate these potential deficits in severely physically impaired ALS patients, eye-tracking is a promising means to conduct cognitive tests. The present article focuses on how eye movements, an indirect means of communication for physically disabled patients, can be utilized to allow for detailed neuropsychological assessment. The requirements, in terms of oculomotor parameters that have to be met for sufficient eye-tracking in ALS patients are presented. The properties of stimuli, including type of neuropsychological tests and style of presentation, best suited to successfully assess cognitive functioning, are also described. Furthermore, recommendations regarding procedural requirements are provided. Overall, this methodology provides a reliable, easy to administer and fast approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS. The only confounding factor might be deficits in voluntary eye movement control in a subset of ALS patients.

Cognitive deficits are common in about one third of patients with amyotrophic lateral sclerosis, a neurological condition leading to progressive impairments in speech and movement abilities. To conduct cognitive tests in patients unable to speak or write a reliable and easy to administer eye-tracking paradigm was developed.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to ...

Control of Eating Behavior Using a Novel Feedback System

Subjects eat food from a plate that sits on a scale connected to a computer that records the weight loss of the plate during the meal and makes up a curve of food intake, meal duration and rate of eating modeled by a quadratic equation. The purpose of the method is to change eating behavior by providing visual feedback on the computer screen that the subject can adapt to because her/his own rate of eating appears on the screen during the meal. The data generated by the method is automatically analyzed and fitted to the quadratic equation using a custom made algorithm. The method has the advantage of recording eating behavior objectively and offers the possibility of changing eating behavior both in experiments and in clinical practice. A limitation may be that experimental subjects are affected by the method. The same limitation may be an advantage in clinical practice, as eating behavior is more easily stabilized by the method. A treatment that uses this method has normalized body weight and restored the health of several hundred patients with anorexia nervosa and other eating disorders and has reduced the weight and improved the health of severely overweight patients.

Subjects eat food from a plate placed on a scale connected to a computer that records the weight loss of the plate during the meal. Feedback on the computer screen allows the subject to adapt her/his eating behavior to reference curves thus normalizing body weight.

Subjects eat food from a plate that sits on a scale connected to a computer that records the weight loss of the plate during the meal and makes up a curve ...

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific responses to changing temperatures according to their physiological tolerance and adaptability. Drosophila flies also possess a temperature sensing system that has become fundamental to understanding the neural basis of temperature processing in ectotherms. We present here a temperature-controlled arena that permits fast and precise temperature changes with temporal and spatial control to explore the response of individual flies to changing temperatures. Individual flies are placed in the arena and exposed to pre-programmed temperature challenges, such as uniform gradual increases in temperature to determine reaction norms or spatially distributed temperatures at the same time to determine preferences. Individuals are automatically tracked, allowing the quantification of speed or location preference. This method can be used to rapidly quantify the response over a large range of temperatures to determine temperature performance curves in Drosophila or other insects of similar size. In addition, it can be used for genetic studies to quantify temperature preferences and reactions of mutants or wild-type flies. This method can help uncover the basis of thermal speciation and adaptation, as well as the neural mechanisms behind temperature processing.

An Automated Method to Determine the Performance of Drosophila in Response to Temperature Changes in Space and Time

Here we present a protocol to automatically determine the locomotor performance of Drosophila at changing temperatures using a programmable temperature-controlled arena that produces fast and accurate temperature changes in time and space.

Temperature is a ubiquitous environmental factor that affects how species distribute and behave. Different species of Drosophila fruit flies have specific ...

Modified Blood Collection from Tail Veins of Non-anesthetized Mice with a Vacuum Blood Collection System and Eyeglass Magnifier

Blood sample collection is the basis of experimental animal research. It is of importance to obtain adequate blood samples for various research purposes. The tail veins of mice are small, and it is sometimes difficult to obtain the required blood volume by conventional puncture methods. This study investigates the superiority of repeated blood sample collection from tail veins of mice through use of a vacuum blood collection system and eyeglass magnifier (experimental group) compared to conventional blood sampling methods (conventional group), performed by beginners and experts, respectively. With the help of an eyeglass magnifier, a butterfly needle tip is inserted into the tail vein of each mouse in the experimental group. When the vein is penetrated successfully, a blood sample is collected in the vacuum collection tube by insertion of the rubber end of a butterfly needle into the vacuum blood collection tube. The plunger is then used to collect blood without the help of the eyeglass magnifier in the conventional group. Success rates of blood sample collection by the beginners and experts were shown to be 70% vs. 100% (p &#60; 0.01) in the experimental group and 35% vs. 85% (p &#60; 0.01) in the conventional group. For both beginners and experts, puncture times required for obtaining required blood sample were significantly lower in the experimental group compared to the conventional group (2.40 &#177; 0.75 vs. 2.90 &#177; 0.31, p &#60; 0.05; 1.15 &#177; 0.37 vs. 1.55 &#177; 0.76, p &#60; 0.05). In conclusion, the presented blood sampling technique is feasible and easy to practice and enables frequent sampling of adequate blood volumes from non-anesthetized mice.&#160;

This study reports blood sampling from tail vein in mice using a vacuum extraction tube system with eyeglass magnifier. Our method is easy to practice and could be used for repeat blood sampling in mice.

Blood sample collection is the basis of experimental animal research. It is of importance to obtain adequate blood samples for various research purposes. ...

An Instrumented Pull Test to Characterize Postural Responses

Impairment of postural reflexes, termed postural instability, is a common and disabling deficit in Parkinson's disease. To assess postural reflexes, clinicians typically employ the pull test to grade corrective responses to a backward perturbation at the shoulders. However, the pull test is prone to issues with reliability and scaling (score/4). Here, we present an instrumented version of the pull test to more precisely quantify postural responses. Akin to the clinical test, pulls are manually administered except pull force is also recorded. Displacements of the trunk and feet are captured by a semi-portable motion tracking system. Raw data represent distance traveled (in millimeter units), making subsequent interpretation and analysis intuitive. The instrumented pull test also detects variabilities influencing pull test administration, such as pull force, thereby identifying and quantifying potential confounds that can be accounted for by statistical techniques. The instrumented pull test could have application in studies seeking to capture early abnormalities in postural responses, track postural instability over time, and detect responses to therapy.

Impairment of postural reflexes, termed postural instability, is difficult to quantify. Clinical assessments such as the pull test suffer issues with reliability and scaling. Here, we present an instrumented version of the pull test to objectively characterize postural responses.

Impairment of postural reflexes, termed postural instability, is a common and disabling deficit in Parkinson's disease. To assess postural reflexes, ...