研究目的：閃頻視覺（stroboscopic vision)是提供視覺明暗間隔來觀察物體連續活動，最近被用於訓練運動員的動作技能。過去的研究發現，閃頻視覺可以改善時間預期和誘發感覺權重的重新分配，對面臨機能退化的老人而言，可能有助於增進訓練老人站立平衡的功效。因此，本研究在傳統的平衡板訓練中加入閃頻視覺，探討是否能藉此增進老年人站立平衡表現。
研究方法：本實驗共收取三十位年齡大於六十歲的健康老年人，並分成閃頻組（平均年齡：64.6 ± 3.0歲；7男8女)和控制組（平均年齡：66.2 ± 2.7歲; 6男9女)。實驗期間，受試者需連續參與三天，第一天進行前測，第二天訓練，第三天後測。在第二天的訓練時，閃頻組進行每次45秒，共十二次的平衡板訓練，閃頻組會配戴閃頻視覺眼鏡，提供週期性的明暗視覺，週期內包含500毫秒正常視覺與500毫秒視覺遮蔽；控制組執行相同平衡訓練，唯一不同在於眼鏡完全不提供暗視覺。前後測內容分為平衡和轉移測驗。平衡測驗在平衡板上進行，分為正常視覺（FV)和閃頻視覺（IVO)兩種情況，其中閃頻視覺同樣以500毫秒明500毫秒暗閃爍，兩種不同視覺執行四次，每次45秒。轉移訓練利用力板測量，受試者需閉眼在軟墊上維持60秒直立，共四次。力板壓力中心數據分為整體軌跡、前後向及左右向。平衡及轉移測試所得資料以均方根（root mean square, RMS)、樣本熵（sample entropy, SampEn)和平均頻率（mean frequency, MF)定量平衡表現。以卡方檢定和獨立樣本t檢定分辨人口學資料是否有差異，均方根、樣本熵和平均頻率則以二因子變異數分析檢定兩組（閃頻組vs. 控制組)在訓練前後（前測vs. 後測)平衡板晃動與力板壓力中心軌跡特徵的異同。
研究結果：平衡板作業部份，無論是正常視覺或閃頻視覺情況下，兩組平衡板晃動的均方根值沒有交互作用和組別主效應，只有時間主效應（正常視覺：p < 0.001，閃頻視覺：p = 0.002)，訓練均方根值顯著減少。平衡板晃動的樣本熵沒有交互作用和組別主效應，但是時間主效應有統計顯著意義（正常視覺：p = 0.002，閃頻視覺：p < 0.001)，訓練後兩組樣本熵皆增加。平均頻率在兩種視覺情況下沒有交互作用，閃頻視覺無組別主效應，但是正常視覺下發現顯著的組別主效應（p = 0.004)，閃頻組在訓練前後皆呈現較大的平均頻率，而兩組也都有時間主效應（正常視覺：p = 0.001，閃頻視覺：p < 0.001)，訓練後平均頻率皆增加。轉移測驗部份，壓力中心整體軌跡均方根呈現時間與組別的交互作用（p = 0.021)，事後檢定結果顯示並無顯著，無組別和時間主效應；前後向和左右向沒有發現任何統計顯著。訓練後，兩組的壓力中心軌跡的樣本熵無交互作用，整體軌跡（p < 0.001)和前後向（p < 0.001)有時間主效應，訓練後軌跡均方根值顯著增加，但是左右向的軌跡均方根值沒有任何統計顯著。壓力中心軌跡的平均頻率僅前後向有交互作用（p = 0.039)，閃頻組在訓練後平均頻率顯著增加（p < 0.001)，沒有發現組別主效應，整體軌跡（p < 0.001)和前後向（p < 0.001)有時間主效應，兩組經過訓練，壓力中心整體軌跡的平均頻率皆增加，但是壓力中心軌跡左右向並未有任何達統計顯著的發現。
結論：平衡板訓練能有效增進老年人平衡能力；然而，在正常視覺下做平衡訓練有較好的轉移效果。不過，老人在閃頻視覺下進行平衡訓練，仍有部分正面的功能助益，在不穩定的平面站立，可表現出較頻繁姿勢調整以及更豐富的調整策略。

Objective: Stroboscopic vision, a visual presentation of continuous motion with a series of intermittent samples, is recently used to improve motor skills of sport players. As stroboscopic vision could facilitate timing anticipation and sensory reweighting for a motor task, it is of potential to train aged people during upright stance. The purpose of the study was to investigate the effects of stabilometer balance training with stroboscopic vision (SV) for older adults.
Methods: Thirty young elderly were assigned to SV group (mean age: 64.6 ± 3.0 yrs; 7 males and 8 females) or control group (mean age: 66.2 ± 2.7 yrs; 6 males and 9 females). The SV group received twelve trials (45 seconds per trial with an inter-trial interval of rest for 3 minutes) of stabilometer training in one day under stroboscopic vision alternately with 500 ms-opaque period and 500 ms-transparent period. The control group repeated the same protocol for stabilometer training as the SV group without opaque state. Four trials of balance task of 45 s stabilometer stance with normal vision (FV) and intermittent visual occlusion (IVO). Transfer tasks were four trials of 60 s upright stance on a foam surface with eyes closed. Both balance and transfer tasks were executed in the pre-test and post-test. Root mean square (RMS), sample entropy (SampEn), and mean frequency (MF) of power spectrum were used to characterize balance performance. Chi square test and independent t test were used to determine group differences in the demographic data. Two-way repeated measures ANOVA was used to examine effects of time (pre-test vs. post-test) and group (SV vs. control) on posture sway characteristics of the balance and transfer tasks.
Results: For the balance task, the SV and control groups exhibited a smaller RMS (FV: p < 0.001, IVO: p = 0.002) and a greater SampEn (FV: p= 0.002, IVO: p< 0.001) of the stabilometer fluctuation movements after training under the FV and IVO conditions. Under the FV and IVO conditions, the SV and control groups had larger MF of the stabilometer fluctuation movements in the post-test than that in the pre-test (FV: p = 0.001, IVO: p < 0.001). For the transfer task, there was a significant interaction effect of time and group (p = 0.021) on the RMS of total COP trajectory, and only the control group significantly exhibited a smaller RMS after training. The SV and control groups exhibited a larger SampEn after training in total COP trajectory (p < 0.001) and COP sway in the AP direction (p < 0.001). MF of COP sway in the AP direction was subject to a significant interaction effect of time and group (p = 0.039), and the SV group had greater MF of COP sway in the post-test than that in the pre-test. For the total COP trajectory, only main effect of time was observed (p < 0.001), which indicated training-related increase in MF for the both groups.
Conclusion: Stabilometer training improved balance performance of older adults, irrespective of provision of stroboscopic vision. However, postural training with normal vision had superior postural transfer effect to that with stroboscopic vision. Nevertheless, older adults could still partly benefit from training with stroboscopic vision, which resulted in richer strategies and increasing corrective attempts for unsteady stance.

Allison LK, Kiemel T, Jeka JJ. Multisensory reweighting of vision and touch is intact in healthy and fall-prone older adults. Exp Brain Res. 2006;175(2):342‐352.
Appelbaum LG, Schroeder JE, Cain MS, Mitroff SR. Improved visual cognition through stroboscopic training. Front Psychol. 2011;2:276.
Appelbaum LG, Cain MS, Schroeder JE, Darling EF, Mitroff SR. Stroboscopic visual training improves information encoding in short-term memory. Atten Percept Psychophys. 2012;74(8):1681‐1691.
Ballester R, Huertas F, Uji M, Bennett SJ. Stroboscopic vision and sustained attention during coincidence-anticipation. Sci Rep. 2017;7(1):17898.
Bennett S, Ashford D, Rioja N, Elliott D. Intermittent vision and one-handed catching: the effect of general and specific task experience. J Mot Behav. 2004;36(4):442‐449.
Buatois S, Gueguen R, Gauchard GC, Benetos A, Perrin PP. Posturography and risk of recurrent falls in healthy non-institutionalized persons aged over 65. Gerontology. 2006;52(6):345‐352.
Carpenter MG, Frank JS, Silcher CP, Peysar GW. The influence of postural threat on the control of upright stance. Exp Brain Res. 2001;138(2):210‐218.
Craig CE, Doumas M. Slowed sensory reweighting and postural illusions in older adults: the moving platform illusion. J Neurophysiol. 2019;121(2):690‐700.
da Costa Barbosa R, Vieira MF. Postural Control of Elderly Adults on Inclined Surfaces. Ann Biomed Eng. 2017;45(3):726‐738.
Eikema DJ, Hatzitaki V, Tzovaras D, Papaxanthis C. Age-dependent modulation of sensory reweighting for controlling posture in a dynamic virtual environment. Age 2012;34(6):1381-1392.
Eikema DJ, Hatzitaki V, Konstantakos V, Papaxanthis C. Elderly adults delay proprioceptive reweighting during the anticipation of collision avoidance when standing. Neuroscience. 2013;234:22-30.
Elliott D, Zuberec S, Milgram P. The effects of periodic visual occlusion on ball catching. J Mot Behav. 1994;26(2):113‐122.
Fetter M. Vestibulo-ocular reflex. Dev Ophthalmol. 2007;40:35‐51.
Fransen J, Lovell TW, Bennett KJ, et al. The influence of restricted visual feedback on dribbling performance in youth soccer players. Motor Control. 2017;21(2):158‐167.
Fernie GR, Gryfe CI, Holliday PJ, Llewellyn A. The relationship of postural sway in standing to the incidence of falls in geriatric subjects. Age Ageing. 1982;11(1):11‐16.
Fukuoka Y, Tanaka K, Ishida A, Minamitani H. Characteristics of visual feedback in postural control during standing. IEEE Trans Neural Syst Rehabil Eng. 1999;7(4), 427-434.
Fukuoka Y, Nagata T, Ishida A, Minamitani H. Characteristics of somatosensory feedback in postural control during standing. IEEE Trans Neural Syst Rehabil Eng. 2001;9(2):145‐153.
Gelbard R, Inaba K, Okoye OT, et al. Falls in the elderly: a modern look at an old problem. Am J Surg. 2014;208(2):249‐253.
Goble DJ, Coxon JP, Wenderoth N, Van Impe A, Swinnen SP. Proprioceptive sensibility in the elderly: degeneration, functional consequences and plastic-adaptive processes. Neurosci Biobehav Rev. 2009;33(3):271‐278.
Grooms DR, Chaudhari A, Page SJ, Nichols-Larsen DS, Onate JA. Visual-Motor Control of Drop Landing After Anterior Cruciate Ligament Reconstruction. J Athl Train. 2018;53(5):486‐496.
Guadagnoli MA, Lee TD. Challenge point: a framework for conceptualizing the effects of various practice conditions in motor learning. J Mot Behav. 2004;36(2):212‐224.
Guerraz M, Yardley L, Bertholon P, et al. Visual vertigo: symptom assessment, spatial orientation and postural control. Brain. 2001;124(Pt 8):1646-1656.
Haibach P, Slobounov S, Newell K. Egomotion and vection in young and elderly adults. Gerontology. 2009;55(6):637‐643.
Hartog LC, Schrijnders D, Landman GWD, et al. Is orthostatic hypotension related to falling? A meta-analysis of individual patient data of prospective observational studies. Age Ageing. 2017;46(4):568‐575.
Hay L, Bard C, Fleury M, Teasdale N. Availability of visual and proprioceptive afferent messages and postural control in elderly adults. Exp Brain Res. 1996;108(1):129‐139.
Horiuchi K, Ishihara M, Imanaka K. The essential role of optical flow in the peripheral visual field for stable quiet standing: Evidence from the use of a head-mounted display. PLoS One. 2017;12(10):e0184552.
Hu MH, Woollacott MH. Multisensory training of standing balance in older adults: I. Postural stability and one-leg stance balance. J Gerontol. 1994;49(2):M52‐M61.
Hülsdünker T, Rentz C, Ruhnow D, Käsbauer H, Strüder HK, Mierau A. The effect of 4-week stroboscopic training on visual function and sport-specific visuomotor performance in top-level badminton players. Int J Sports Physiol Perform. 2019;14(3):343‐350.
Hwang IS, Huang CT, Yang JF, Guo MC. Characterization of information-based learning benefits with submovement dynamics and muscular rhythmicity. PLoS One. 2013;8(12):e82920.
Jansen S, Bhangu J, de Rooij S, Daams J, Kenny RA, van der Velde N. The Association of Cardiovascular Disorders and Falls: A Systematic Review. J Am Med Dir Assoc. 2016;17(3):193‐199.
Jarus T, Gutman T. Effects of cognitive processes and task complexity on acquisition, retention, and transfer of motor skills. Can J Occup Ther. 2001;68(5):280‐289.
Jeka J, Allison L, Saffer M, Zhang Y, Carver S, Kiemel T. Sensory reweighting with translational visual stimuli in young and elderly adults: the role of state-dependent noise. Exp Brain Res. 2006;174(3):517-527.
Jeka JJ, Allison LK, Kiemel T. The dynamics of visual reweighting in healthy and fall-prone older adults. J Mot Behav. 2010;42(4):197‐208.
Jones GM, Mandl G. Motion sickness due to vision reversal: its absence in stroboscopic light. Ann N Y Acad Sci. 1981;374:303‐311.
Kim KM, Kim JS, Grooms DR. Stroboscopic vision to induce sensory reweighting during postural control. J Sport Rehabil. 2017;26(5):10.1123/jsr.2017-0035.
Kim KM, Kim JS, Oh J, Grooms DR. Stroboscopic Vision as a Dynamic Sensory Reweighting Alternative to the Sensory Organization Test [published online ahead of print, 2020 May 29]. J Sport Rehabil. 2020;1‐7.
Koppelaar H, Kordestani Moghadam P, Khan K, Kouhkani S, Segers G, Warmerdam MV. Reaction Time Improvements by Neural Bistability. Behav Sci (Basel). 2019;9(3):28.
Lacour M, Borel L. Vestibular control of posture and gait. Arch Ital Biol. 1993;131(2-3):81‐104.
Lajoie Y, Gallagher SP. Predicting falls within the elderly community: comparison of postural sway, reaction time, the Berg balance scale and the Activities-specific Balance Confidence (ABC) scale for comparing fallers and non-fallers. Arch Gerontol Geriatr. 2004;38(1):11‐26.
Laurence BD, Michel L. The Fall in Older Adults: Physical and Cognitive Problems. Curr Aging Sci. 2017;10(3):185‐200.
Lockhart TE, Liu J. Differentiating fall-prone and healthy adults using local dynamic stability. Ergonomics. 2008;51(12):1860‐1872.
Lopez C, Lacour M, Ahmadi AE, Magnan J, Borel L. Changes of visual vertical perception: a long-term sign of unilateral and bilateral vestibular loss. Neuropsychologia. 2007;45(9):2025‐2037.
Lord SR, Clark RD, Webster IW. Postural stability and associated physiological factors in a population of aged persons. J Gerontol. 1991;46(3):M69‐M76.
Lord SR, Ward JA, Williams P, Anstey KJ. Physiological factors associated with falls in older community-dwelling women. J Am Geriatr Soc. 1994;42(10):1110‐1117.
Lord SR, Menz HB. Visual contributions to postural stability in older adults. Gerontology. 2000;46(6):306‐310.
Lord SR. Visual risk factors for falls in older people. Age Ageing. 2006;35 Suppl 2:ii42‐ii45.
Maes L, Dhooge I, D'haenens W, et al. The effect of age on the sinusoidal harmonic acceleration test, pseudorandom rotation test, velocity step test, caloric test, and vestibular-evoked myogenic potential test. Ear Hear. 2010;31(1):84-94.
Martínez-Amat A, Hita-Contreras F, Lomas-Vega R, Caballero-Martínez I, Alvarez PJ, Martínez-López E. Effects of 12-week proprioception training program on postural stability, gait, and balance in older adults: a controlled clinical trial. J Strength Cond Res. 2013;27(8):2180‐2188.
McChesney JW, Woollacott MH. The effect of age-related declines in proprioception and total knee replacement on postural control. J Gerontol A Biol Sci Med Sci. 2000;55(11):M658‐M666.
McGovern DP, Astle AT, Clavin SL, Newell FN. Task-specific transfer of perceptual learning across sensory modalities. Curr Biol. 2016;26(1):R20‐R21.
McManus M, D'Amour S, Harris LR. Using optic flow in the far peripheral field. J Vis. 2017;17(8):3.
Melzer I, Benjuya N, Kaplanski J. Postural stability in the elderly: a comparison between fallers and non-fallers. Age Ageing. 2004;33(6):602‐607.
Menant JC, St George RJ, Fitzpatrick RC, Lord SR. Perception of the postural vertical and falls in older people. Gerontology. 2012;58(6):497‐503.
Milgram P. A spectacle-mounted liquid-crystal tachistoscope. Behav Res Methods. 1987;19(5):449-456.
Mitroff SR, Friesen P, Bennett D, Yoo H, Reichow AW. Enhancing ice hockey skills through stroboscopic visual training: a pilot study. Athl. Train. Sports Health Care. 2013; 5(6): 261-264.
Nelson-Wong E, Appell R, McKay M, et al. Increased fall risk is associated with elevated co-contraction about the ankle during static balance challenges in older adults. Eur J Appl Physiol. 2012;112(4):1379-1389.
Ogaya S, Ikezoe T, Soda N, Ichihashi N. Effects of balance training using wobble boards in the elderly. J Strength Cond Res. 2011;25(9):2616‐2622.
Oie KS, Kiemel T, Jeka JJ. Multisensory fusion: simultaneous re-weighting of vision and touch for the control of human posture. Brain Res Cogn Brain Res. 2002;14(1):164‐176.
Pasma JH, Engelhart D, Maier AB, Schouten AC, van der Kooij H, Meskers CG. Changes in sensory reweighting of proprioceptive information during standing balance with age and disease. J Neurophysiol. 2015;114(6):3220‐3233.
Pijnappels M, van der Burg PJ, Reeves ND, van Dieën JH. Identification of elderly fallers by muscle strength measures. Eur J Appl Physiol. 2008;102(5):585‐592.
Pinheiro Menuchi MR, Bucken Gobbi LT. Optic flow contribution to locomotion adjustments in obstacle avoidance. Motor Control. 2012;16(4):506-520.
Reschke MF, Somers JT, Ford G. Stroboscopic vision as a treatment for motion sickness: strobe lighting vs. shutter glasses. Aviat Space Environ Med. 2006;77(1):2‐7.
Riva D, Mamo C, Fanì M, et al. Single stance stability and proprioceptive control in older adults living at home: gender and age differences. J Aging Res. 2013;2013:561695.
Riva D, Fani M, Benedetti MG, Scarsini A, Rocca F, Mamo C. Effects of High-Frequency Proprioceptive Training on Single Stance Stability in Older Adults: Implications for Fall Prevention. Biomed Res Int. 2019;2019:2382747.
Robertson S, Collins J, Elliott D, Starkes J. The Influence of Skill and Intermittent Vision on Dynamic Balance. J Mot Behav. 1994;26(4):333‐339.
Roerdink M, Hlavackova P, Vuillerme N. Center-of-pressure regularity as a marker for attentional investment in postural control: a comparison between sitting and standing postures. Hum Mov Sci. 2011;30(2):203‐212.
Shalmoni N, Kalron A. The immediate effect of stroboscopic visual training on information-processing time in people with multiple sclerosis: an exploratory study. J Neural Transm (Vienna). 2020;10.1007/s00702-020-02190-2.
Sihvonen SE, Sipilä S, Era PA. Changes in postural balance in frail elderly women during a 4-week visual feedback training: a randomized controlled trial. Gerontology. 2004;50(2):87‐95.
Simoneau M, Teasdale N, Bourdin C, Bard C, Fleury M, Nougier V. Aging and postural control: postural perturbations caused by changing the visual anchor. J Am Geriatr Soc. 1999;47:235–240
Smith PJ. Attention and the contextual interference effect for a continuous task. Percept Mot Skills. 1997;84(1):83‐92.
Smith TQ, Mitroff SR. Stroboscopic Training Enhances Anticipatory Timing. Int J Exerc Sci. 2012;5(4):344‐353.
Stelmach GE, Sirica A. Aging and proprioception. Age 1986;9(4):99-103.
Sundermier L, Woollacott MH, Jensen JL, Moore S. Postural sensitivity to visual flow in aging adults with and without balance problems. J Gerontol A Biol Sci Med Sci. 1996;51(2):M45-M52.
Tinetti ME, Williams CS. The effect of falls and fall injuries on functioning in community-dwelling older persons. J Gerontol A Biol Sci Med Sci. 1998;53(2):M112‐M119.
Tsai YC, Hsieh LF, Yang S. Age-related changes in posture response under a continuous and unexpected perturbation. J Biomech. 2014;47(2):482‐490.
Van Konynenburg P, Marsland S, McCoy J. Solar radiation control using NCAP liquid crystal technology. Sol Energy Mater. 1989;19(1-2): 27-41.
Ward RE, Quach L, Welch SA, Leveille SG, Leritz E, Bean JF. Interrelated Neuromuscular and Clinical Risk Factors That Contribute to Falls. J Gerontol A Biol Sci Med Sci. 2019;74(9):1526‐1532.
Webb CM, Estrada A, Athy JR. Motion sickness prevention by an 8-Hz stroboscopic environment during air transport. Aviat Space Environ Med. 2013;84(3):177‐183.
Whipple R, Wolfson L, Derby C, Singh D, Tobin J. Altered sensory function and balance in older persons. J Gerontol. 1993;48 Spec No:71‐76.
Whitehurst M, Del Rey P. Effects of contextual interference, task difficulty, and levels of processing on pursuit tracking. Percept Mot Skills. 1983;57(2):619‐628.
Wiesmeier IK, Dalin D, Maurer C. Elderly Use Proprioception Rather than Visual and Vestibular Cues for Postural Motor Control. Front Aging Neurosci. 2015;7:97.
Wilkins L, Gray R. Effects of stroboscopic visual training on visual attention, motion perception, and catching performance. Percept Mot Skills. 2015;121(1):57‐79.
Wilkins L, Appelbaum LG. An early review of stroboscopic visual training: insights, challenges and accomplishments to guide future studies. Int Rev Sport Exerc Psychol. 2019:1-16.
Wiksten DL, Perrin DH, Hartman ML, Gieck J, Weltman A. The relationship between muscle and balance performance as a function of age. Isokinet Exerc Sci. 1996;6(2),125-132.
Williams HG, McClenaghan BA, Dickerson J. Spectral characteristics of postural control in elderly individuals. Arch Phys Med Rehab. 1997;78(7), 737-744.
Woollacott MH, Shumway-Cook A, Nashner LM. Aging and posture control: changes in sensory organization and muscular coordination. Int J Aging Hum Dev. 1986;23(2):97‐114.
Zalewski CK. Aging of the Human Vestibular System. Semin Hear. 2015;36(3):175‐196.
Zavlin D, Chegireddy V, Nguyen-Lee JJ, et al. Training Effects of Visual Stroboscopic Impairment on Surgical Performance: A Randomized-Controlled Trial. J Surg Educ. 2019;76(2):560‐567.