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. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Achievement+of+simple+mobility+milestones+after+stroke.">Achievement of simple mobility milestones after stroke.</a> Arch Phys Med Rehabil. 80 (4), 442-447 (1999).</li><li>Langhorne, P., Bernhardt, J., Kwakkel, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stroke+rehabilitation.">Stroke rehabilitation.</a> Lancet. 377 (9778), 1693-1702 (2011).</li><li>Veerbeek, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+is+the+evidence+for+physical+therapy+poststroke?+A+systematic+review+and+meta-analysis.">What is the evidence for physical therapy poststroke? 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. C., Halvorsen, K., Borg, J., Hirschfeld, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+coordination+of+the+sit-to-walk+task+in+subjects+with+stroke+and+in+controls.">Temporal coordination of the sit-to-walk task in subjects with stroke and in controls.</a> Arch Phys Med Rehabil. 90 (6), 1009-1017 (2009).</li><li>Dehail, P., 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=Kinematic+and+electromyographic+analysis+of+rising+from+a+chair+during+a+&amp;#34;Sit-to-Walk&amp;#34;+task+in+elderly+subjects:+role+of+strength.">Kinematic and electromyographic analysis of rising from a chair during a &amp;#34;Sit-to-Walk&amp;#34; task in elderly subjects: role of strength.</a> Clin Biomech (Bristol, Avon). 22 (10), 1096-1103 (2007).</li><li>Buckley, T., Pitsikoulis, C., Barthelemy, E., 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=Age+impairs+sit-to-walk+motor+performance.">Age impairs sit-to-walk motor performance.</a> J Biomech. 42 (14), 2318-2322 (2009).</li><li>Roy, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+foot+position+and+chair+height+on+the+asymmetry+of+vertical+forces+during+sit-to-stand+and+stand-to-sit+tasks+in+individuals+with+hemiparesis.">The effect of foot position and chair height on the asymmetry of vertical forces during sit-to-stand and stand-to-sit tasks in individuals with hemiparesis.</a> Clin Biomech (Bristol, Avon). 21 (6), 585-593 (2006).</li><li>Kubinski, S. N., McQueen, C. A., Sittloh, K. A., Dean, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Walking+with+wider+steps+increases+stance+phase+gluteus+medius+activity.">Walking with wider steps increases stance phase gluteus medius activity.</a> Gait Posture. 41 (1), 130-135 (2015).</li><li>Jian, Y., Winter, D. A., Ishac, M. G., Gilchrist, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trajectory+of+the+body+COG+and+COP+during+initiation+and+termination+of+gait.">Trajectory of the body COG and COP during initiation and termination of gait.</a> Gait Posture. 1 (1), 9-22 (1993).</li><li>Winter, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+balance+and+posture+control+during+standing+and+walking.">Human balance and posture control during standing and walking.</a> Gait Posture. 3 (4), 193-214 (1995).</li><li>Cavanagh, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+technique+for+averaging+center+of+pressure+paths+from+a+force+platform.">A technique for averaging center of pressure paths from a force platform.</a> J Biomech. 11 (10-12), 487-491 (1978).</li><li>Halliday, S. E., Winter, D. A., Frank, J. S., Patla, A. E., Prince, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+initiation+of+gait+in+young,+elderly,+and+Parkinson's+disease+subjects.">The initiation of gait in young, elderly, and Parkinson's disease subjects.</a> Gait Posture. 8 (1), 8-14 (1998).</li><li>Hass, C. J., Waddell, D. E., Fleming, R. P., Juncos, J. L., Gregor, R. J. <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+and+dynamic+balance+control+in+Parkinson's+disease.">Gait initiation and dynamic balance control in Parkinson's disease.</a> Arch Phys Med Rehabil. 86 (11), 2172-2176 (2005).</li><li>Winter, D. A., Patla, A. E., Ishac, M., Gage, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+mechanisms+of+balance+during+quiet+standing.">Motor mechanisms of balance during quiet standing.</a> J Electromyogr Kinesiol. 13 (1), 49-56 (2003).</li><li>Cappozzo, A., Catani, F., Croce, U. D., Leardini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Position+and+orientation+in+space+of+bones+during+movement:+anatomical+frame+definition+and+determination.">Position and orientation in space of bones during movement: anatomical frame definition and determination.</a> Clin Biomech (Bristol, Avon). 10 (4), 171-178 (1995).</li><li>Dempster, W. T., Gabel, W. C., Felts, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+anthropometry+of+the+manual+work+space+for+the+seated+subject.">The anthropometry of the manual work space for the seated subject.</a> Am J Phys Anthropol. 17 (4), 289-317 (1959).</li><li>Jones, G. D., James, D. C., Thacker, M., Jones, E. J., Green, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sit-to-Walk+and+Sit-to-Stand-and-Walk+Task+Dynamics+are+Maintained+During+Rising+at+an+Elevated+Seat-Height+Independent+of+Lead-Limb+in+Healthy+Individuals.">Sit-to-Walk and Sit-to-Stand-and-Walk Task Dynamics are Maintained During Rising at an Elevated Seat-Height Independent of Lead-Limb in Healthy Individuals.</a> Gait Posture. 48, 226-229 (2016).</li><li>Qualysis AB. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Qualysis Track Manager User Manual. , (2011).</li><li>Hoffman, M., Schrader, J., Applegate, T., Koceja, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilateral+postural+control+of+the+functionally+dominant+and+nondominant+extremities+of+healthy+subjects.">Unilateral postural control of the functionally dominant and nondominant extremities of healthy subjects.</a> J Athl Train. 33 (4), 319-322 (1998).</li><li>Ren, L., Jones, R. K., Howard, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whole+body+inverse+dynamics+over+a+complete+gait+cycle+based+only+on+measured+kinematics.">Whole body inverse dynamics over a complete gait cycle based only on measured kinematics.</a> J Biomech. 41 (12), 2750-2759 (2008).</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> Tutorial: Building a Model. , (2013).</li><li>Kainz, H., Carty, C. P., Modenese, L., Boyd, R. N., Lloyd, 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=Estimation+of+the+hip+joint+centre+in+human+motion+analysis:+a+systematic+review.">Estimation of the hip joint centre in human motion analysis: a systematic review.</a> Clin Biomech (Bristol, Avon). 30 (4), 319-329 (2015).</li><li>Harrington, M. E., Zavatsky, A. B., Lawson, S. E., Yuan, Z., Theologis, T. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+the+hip+joint+centre+in+adults,+children,+and+patients+with+cerebral+palsy+based+on+magnetic+resonance+imaging.">Prediction of the hip joint centre in adults, children, and patients with cerebral palsy based on magnetic resonance imaging.</a> J Biomech. 40 (3), 595-602 (2007).</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> Coda Pelvis. , (2015).</li><li>Bell, A. L., Brand, R. A., Pedersen, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prediction+of+hip+joint+centre+location+from+external+landmarks.">Prediction of hip joint centre location from external landmarks.</a> Human movement science. 8 (1), 3-16 (1989).</li><li>Eames, M. H. 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. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantifying+human+movement+across+the+continuum+of+care:+From+lab+to+clinic+to+community.">Quantifying human movement across the continuum of care: From lab to clinic to community.</a> J Neurosci Methods. 231, 18-21 (2014).</li><li>Pai, Y. C., Rogers, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Segmental+contributions+to+total+body+momentum+in+sit-to-stand.">Segmental contributions to total body momentum in sit-to-stand.</a> Medicine and Science in Sports and Exercise. 23 (2), 225-230 (1991).</li><li>Hughes, M. A., Weiner, D. K., Schenkman, M. L., Long, R. M., Studenski, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chair+rise+strategies+in+the+elderly.">Chair rise strategies in the elderly.</a> Clin Biomech (Bristol, Avon). 9 (3), 187-192 (1994).</li><li>Medeiros, D. L., Concei&#231;&#227;o, J. S., Graciosa, M. D., Koch, D. B., Santos, M. J., Ries, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+seat+heights+and+foot+placement+positions+on+postural+control+in+children+with+cerebral+palsy+during+a+sit-to-stand+task.">The influence of seat heights and foot placement positions on postural control in children with cerebral palsy during a sit-to-stand task.</a> Res Dev Disabil. 43-44, 1-10 (2015).</li><li>Breniere, Y., Do, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=When+and+how+does+steady+state+gait+movement+induced+from+upright+posture+begin?.">When and how does steady state gait movement induced from upright posture begin?.</a> J Biomech. 19 (12), 1035-1040 (1986).</li><li>Weerdesteyn, V., de Niet, M., van Duijnhoven, H. J., Geurts, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Falls+in+individuals+with+stroke.">Falls in individuals with stroke.</a> J Rehabil Res Dev. 45 (8), 1195-1213 (2008).</li></ol>

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>
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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: ...

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