ISway: a sensitive, valid and reliable measure of postural control

Martina Mancini, Arash Salarian, Patricia Carlson-Kuhta, Cris Zampieri, Laurie King, Lorenzo Chiari, Fay B Horak, Martina Mancini, Arash Salarian, Patricia Carlson-Kuhta, Cris Zampieri, Laurie King, Lorenzo Chiari, Fay B Horak

Abstract

Background: Clinicians need a practical, objective test of postural control that is sensitive to mild neurological disease, shows experimental and clinical validity, and has good test-retest reliability. We developed an instrumented test of postural sway (ISway) using a body-worn accelerometer to offer an objective and practical measure of postural control.

Methods: We conducted two separate studies with two groups of subjects. Study I: sensitivity and experimental concurrent validity. Thirteen subjects with early, untreated Parkinson's disease (PD) and 12 age-matched control subjects (CTR) were tested in the laboratory, to compare sway from force-plate COP and inertial sensors. Study II: test-retest reliability and clinical concurrent validity. A different set of 17 early-to-moderate, treated PD (tested ON medication), and 17 age-matched CTR subjects were tested in the clinic to compare clinical balance tests with sway from inertial sensors. For reliability, the sensor was removed, subjects rested for 30 min, and the protocol was repeated. Thirteen sway measures (7 time-domain, 5 frequency-domain measures, and JERK) were computed from the 2D time series acceleration (ACC) data to determine the best metrics for a clinical balance test.

Results: Both center of pressure (COP) and ACC measures differentiated sway between CTR and untreated PD. JERK and time-domain measures showed the best test-retest reliability (JERK ICC was 0.86 in PD and 0.87 in CTR; time-domain measures ICC ranged from 0.55 to 0.84 in PD and from 0.60 to 0.89 in CTR). JERK, all but one time-domain measure, and one frequency measure were significantly correlated with the clinical postural stability score (r ranged from 0.50 to 0.63, 0.01 < p < 0.05).

Conclusions: Based on these results, we recommend a subset of the most sensitive, reliable, and valid ISway measures to characterize posture control in PD: 1) JERK, 2) RMS amplitude and mean velocity from the time-domain measures, and 3) centroidal frequency as the best frequency measure, as valid and reliable measures of balance control from ISway.

Figures

Figure 1
Figure 1
Center of pressure (left panel) and acceleration (right panel) traces in the horizontal plane for three representative subjects.

References

    1. Melzer I, Benjuya N, Kaplanski J. Postural stability in the elderly: a comparison between fallers and non-fallers. Age Ageing. 2004;33:602–607. doi: 10.1093/ageing/afh218.
    1. Najafi B, Horn D, Marclay S, Crews RT, Wu S, Wrobel JS. Assessing postural control and postural control strategy in diabetes patients using innovative and wearable technology. J Diabetes Sci Technol. 2010;4:780–791.
    1. Menant JC, Latt MD, Menz HB, Fung VS, Lord SR. Postural sway approaches center of mass stability limits in Parkinson's disease. Mov Disord. 2011;26:637–643. doi: 10.1002/mds.23547.
    1. Bronte-Stewart HM, Minn AY, Rodrigues K, Buckley EL, Nashner LM. Postural instability in idiopathic Parkinson's disease: the role of medication and unilateral pallidotomy. Brain. 2002;125:2100–2114. doi: 10.1093/brain/awf207.
    1. Maurer C, Mergner T, Xie J, Faist M, Pollak P, Lucking CH. Effect of chronic bilateral subthalamic nucleus (STN) stimulation on postural control in Parkinson's disease. Brain. 2003;126:1146–1163. doi: 10.1093/brain/awg100.
    1. Rocchi L, Chiari L, Horak FB. Effects of deep brain stimulation and levodopa on postural sway in Parkinson's disease. J Neurol Neurosurg Psychiatry. 2002;73:267–274. doi: 10.1136/jnnp.73.3.267.
    1. Bloem BR, Beckley DJ, van Hilten BJ, Roos RA. Clinimetrics of postural instability in Parkinson's disease. J Neurol. 1998;245:669–673. doi: 10.1007/s004150050265.
    1. Beuter A, Hernandez R, Rigal R, Modolo J, Blanchet PJ. Postural sway and effect of levodopa in early Parkinson's disease. Can J Neurol Sci. 2008;35:65–68.
    1. Chastan N, Debono B, Maltete D, Weber J. Discordance between measured postural instability and absence of clinical symptoms in Parkinson's disease patients in the early stages of the disease. Mov Disord. 2008;23:366–372. doi: 10.1002/mds.21840.
    1. Mancini M, Horak FB, Zampieri C, Carlson-Kuhta P, Nutt JG, Chiari L. Trunk accelerometry reveals postural instability in untreated Parkinson's disease. Parkinsonism Relat Disord. 2011;17:557–562. doi: 10.1016/j.parkreldis.2011.05.010.
    1. Dibble LE, Lange M. Predicting falls in individuals with Parkinson disease: a reconsideration of clinical balance measures. J Neurol Phys Ther. 2006;30:60–67.
    1. Ebersbach G, Baas H, Csoti I, Mungersdorf M, Deuschl G. Scales in Parkinson's disease. J Neurol. 2006;253(Suppl 4):IV32–IV35.
    1. Haaxma CA, Bloem BR, Borm GF, Horstink MW. Comparison of a timed motor test battery to the Unified Parkinson's Disease Rating Scale-III in Parkinson's disease. Mov Disord. 2008;23:1707–1717. doi: 10.1002/mds.22197.
    1. Horak FB, Wrisley DM, Frank J. The Balance Evaluation Systems Test (BESTest) to differentiate balance deficits. Phys Ther. 2009;89:484–498. doi: 10.2522/ptj.20080071.
    1. Frenklach A, Louie S, Koop MM, Bronte-Stewart H. Excessive postural sway and the risk of falls at different stages of Parkinson's disease. Mov Disord. 2009;24:377–385. doi: 10.1002/mds.22358.
    1. Swanenburg J, de Bruin ED, Uebelhart D, Mulder T. Falls prediction in elderly people: a 1-year prospective study. Gait Posture. 2010;31:317–321. doi: 10.1016/j.gaitpost.2009.11.013.
    1. Keus SH, Nieuwboer A, Bloem BR, Borm GF, Munneke M. Clinimetric analyses of the Modified Parkinson Activity Scale. Parkinsonism Relat Disord. 2009;15:263–269. doi: 10.1016/j.parkreldis.2008.06.003.
    1. Whitney SL, Roche JL, Marchetti GF, Lin CC, Steed DP, Furman GR, Musolino MC, Redfern MS. A comparison of accelerometry and center of pressure measures during computerized dynamic posturography: a measure of balance. Gait Posture. 2011;33:594–599. doi: 10.1016/j.gaitpost.2011.01.015.
    1. Mayagoitia RE, Lotters JC, Veltink PH, Hermens H. Standing balance evaluation using a triaxial accelerometer. Gait Posture. 2002;16:55–59. doi: 10.1016/S0966-6362(01)00199-0.
    1. Adlerton AK, Moritz U, Moe-Nilssen R. Forceplate and accelerometer measures for evaluating the effect of muscle fatigue on postural control during one-legged stance. Physiother Res Int. 2003;8:187–199. doi: 10.1002/pri.289.
    1. Moe-Nilssen R, Helbostad JL. Trunk accelerometry as a measure of balance control during quiet standing. Gait Posture. 2002;16:60–68. doi: 10.1016/S0966-6362(01)00200-4.
    1. Amiridis IG, Hatzitaki V, Arabatzi F. Age-induced modifications of static postural control in humans. Neurosci Lett. 2003;350:137–140. doi: 10.1016/S0304-3940(03)00878-4.
    1. Maki BE, Holliday PJ, Fernie GR. Aging and postural control. A comparison of spontaneous- and induced-sway balance tests. J Am Geriatr Soc. 1990;38:1–9.
    1. Prieto TE, Myklebust JB, Hoffmann RG, Lovett EG, Myklebust BM. Measures of postural steadiness: differences between healthy young and elderly adults. IEEE Trans Biomed Eng. 1996;43:956–966. doi: 10.1109/10.532130.
    1. Mancini M, Horak FB. The relevance of clinical balance assessment tools to differentiate balance deficits. Eur J Phys Rehabil Med. 2010;46:239–248.
    1. Moe-Nilssen R, Nordin E, Lundin-Olsson L. Criteria for evaluation of measurement properties of clinical balance measures for use in fall prevention studies. J Eval Clin Pract. 2008;14:236–240. doi: 10.1111/j.1365-2753.2007.00839.x.
    1. Moe-Nilssen R. Test-retest reliability of trunk accelerometry during standing and walking. Arch Phys Med Rehabil. 1998;79:1377–1385. doi: 10.1016/S0003-9993(98)90231-3.
    1. Fahn S, Elton R. In: Recent Developments in Parkinson's Disease. Fahn S, Marsden CD, Calne D, Goldstein M, editor. Florham Park: Macmillan Healthcare Information; 1987. The UPDRS Development Committee. Unified Parkinson's disease rating scale; pp. 153–163.
    1. McIlroy WE, Maki BE. Preferred placement of the feet during quiet stance: development of a standardized foot placement for balance testing. Clin Biomech (Bristol, Avon) 1997;12:66–70. doi: 10.1016/S0268-0033(96)00040-X.
    1. Moe-Nilssen R. A new method for evaluating motor control in gait under real-life environmental conditions. Part 1: The instrument. Clin Biomech (Bristol, Avon) 1998;13:320–327. doi: 10.1016/S0268-0033(98)00089-8.
    1. Kerr G, Morrison S, Silburn P. Coupling between limb tremor and postural sway in Parkinson's disease. Mov Disord. 2008;23:386–394. doi: 10.1002/mds.21851.
    1. McGraw KO, Wong SP. Forming Inferences About Some Intraclass Correlation Coefficients. Psychol Methods. 1996;1:30–46.
    1. Winter DA. Human balance and posture control during standing and walking. Gait Posture. 1995;3:193–214. doi: 10.1016/0966-6362(96)82849-9.
    1. Hasan SS, Robin DW, Szurkus DC, Ashmead DH, Peterson SW, Schiavi R. Simultaneous measurement of body center of pressure and center of gravity during upright stance. Part II: Amplitude and frequency data. Gait Posture. 1996;4:11–20. doi: 10.1016/0966-6362(95)01031-9.
    1. Peterka RJ. Sensorimotor integration in human postural control. J Neurophysiol. 2002;88:1097–1118.
    1. Creath R, Kiemel T, Horak F, Peterka R, Jeka J. A unified view of quiet and perturbed stance: simultaneous co-existing excitable modes. Neurosci Lett. 2005;377:75–80. doi: 10.1016/j.neulet.2004.11.071.
    1. Benvenuti F, Mecacci R, Gineprari I, Bandinelli S, Benvenuti E, Ferrucci L, Baroni A, Rabuffetti M, Hallett M, Dambrosia JM, Stanhope SJ. Kinematic characteristics of standing disequilibrium: reliability and validity of a posturographic protocol. Arch Phys Med Rehabil. 1999;80:278–287. doi: 10.1016/S0003-9993(99)90138-7.
    1. Lafond D, Corriveau H, Hebert R, Prince F. Intrasession reliability of center of pressure measures of postural steadiness in healthy elderly people. Arch Phys Med Rehabil. 2004;85:896–901. doi: 10.1016/j.apmr.2003.08.089.
    1. Bakker M, Esselink RA, Munneke M, Limousin-Dowsey P, Speelman HD, Bloem BR. Effects of stereotactic neurosurgery on postural instability and gait in Parkinson's disease. Mov Disord. 2004;19:1092–1099. doi: 10.1002/mds.20116.
    1. St George RJ, Nutt JG, Burchiel KJ, Horak FB. A meta-regression of the long-term effects of deep brain stimulation on balance and gait in PD. Neurology. 2010;75:1292–1299. doi: 10.1212/WNL.0b013e3181f61329.
    1. Spain RI, St George RJ, Salarian A, Mancini M, Wagner JM, Horak FB, Bourdette D. Body-worn motion sensors detect balance and gait deficits in people with multiple sclerosis who have normal walking speed. Gait Posture. 2012;35:573–578. doi: 10.1016/j.gaitpost.2011.11.026.
    1. Maurer C, Peterka RJ. A new interpretation of spontaneous sway measures based on a simple model of human postural control. J Neurophysiol. 2005;93:189–200.
    1. Rocchi L, Chiari L, Cappello A. Feature selection of stabilometric parameters based on principal component analysis. Med Biol Eng Comput. 2004;42:71–79. doi: 10.1007/BF02351013.
    1. Rocchi L, Chiari L, Cappello A, Horak FB. Identification of distinct characteristics of postural sway in Parkinson's disease: a feature selection procedure based on principal component analysis. Neurosci Lett. 2006;394:140–145. doi: 10.1016/j.neulet.2005.10.020.

Source: PubMed

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