姿勢控制障礙是思覺失調症患者常見的功能障礙，對日常生活功能與工作造成相當的影響。然而關於思覺失調症患者姿勢控制的研究卻付之闕如，現有的研究亦侷限在探討靜態的姿勢穩定度。因此本研究意圖藉由模擬或實際的日常功能性動作，由三個不同的面向更全面且廣泛地探討思覺失調症患者姿勢控制: (1)研究思覺失調症患者在不同的感覺情境中之姿勢穩定度，以及其用以維持姿勢穩定度的平衡感覺策略；(2)研究思覺失調症患者如何動態控制姿勢，以追尋環境中移動的目標； (3)探討思覺失調症患者站著彎腰拾取地上物的姿勢極限，同時檢驗實體目標的存在對伸手及姿勢極限的影響；(4)分析臨床症狀與用藥和姿勢控制變項之間的相關性。
三十二位思覺失調症患者與29位健康控制組參與此研究，每位受試者皆經歷三個子研究測驗，分別為感覺組織測試，用以探討姿勢穩定度與平衡策略；規律重心移動測試，用以研究因應移動目標的時空與速度限制，維持動態姿勢平衡的能力；修訂版功能性伸手測試，藉由站立下彎腰伸手向前的姿勢，探討姿勢極限以及實體目標對姿勢極限的影響。本研究使用動態平衡儀與力版捕捉受試者重心壓力的資料，研究參數包括:定點下身體前擺動幅度的平衡分數；各種姿勢控制相關基本感覺的使用比例；運動軸上重心移動的速度與目標速度的差距；重心沿著著運動軸移動的偏移比例；判斷彎腰伸手拾物的極限距離所需的次數、初始感知到的以及實際上伸手拾物的極限距離；彎腰伸手拾物時間；以及前後方向最大的重心位移和其最大速度。
結果顯示相對於健康受試者，思覺失調症患者定點下前後姿勢擺動幅度，整體而言顯著較大。在環境中的感覺間有衝突的姿勢情境中顯著跌倒次數較多，並且使用前庭覺以維持姿勢穩定度有困難。因應移動目標物動態維持姿勢時，不論是控制速度以配合目標移動的節奏，或是控制身體來回移動以追隨移動目標的軌跡，都有明顯的困難。雖然彎腰伸手及物中，所有的參數都與對照組沒有統計上的差異，然而思覺失調症患者需要判斷顯著較多次方能接近真實的重心移動向前的極限，判斷伸手向前極限距離的誤差亦較大。實體目標的呈現有助於兩組受試者增進動作計畫的效率，但只有顯著增加思覺失調症患者的前後方向姿勢極限。針對患者探討姿勢控制與臨床資料的相關時，發現年齡的增加與姿勢穩定度、方向控制、彎腰拾取實物目標姿勢極限的下降顯著相關。抗精神症狀藥物劑量與正確感知內在姿勢表示形式有正向相關。
整體而論，思覺失調症患者除了姿勢穩定度不佳，其感覺策略的使用及動態姿勢控制皆有困難。除此之外，對自己姿勢穩定極限有不正確的覺知。因此建議臨床上應正視思覺失調症患者的姿勢控制障礙，並且針對各有障礙的姿勢控制能力提供常規性的評估與介入。

Postural dysfunctions are prevalent in patients with schizophrenia and affect their daily life and ability to work. However, few studies had endeavored to scrutinize postural control of patients with schizophrenia, moreover, previous studies focused only on postural stability. This study attempted to meet the research gaps with a threefold purpose: (1) to examine how patients with schizophrenia coordinate multiple sensory systems to maintain postural stability; (2) to explore how patients with schizophrenia control posture in a rhythmic way to meet timely external constrains; (3) to investigate limits of stability in standing when bending forward and downward to reach or retrieve, as well as the effect of the presence of targets on postural control for patients with schizophrenia; (4) to explore relationships between clinical data and postural control.
Twenty-nine patients with schizophrenia from day care and 32 matching control participants were recruited. Postural stability was examined by the sensory organization test; self-initiate postural control was investigated by the rhythmic weight shift test; and postural control in the whole-body reaching was tested by the modified functional reach test. The excursion of the center of pressure (COP) was measured by the Balance Master System and Bertec force plate system. Variables including equilibrium scores to indicate the range of anterior-posterior (AP) postural sway; sensory ratios to explore the ability to use sensory information for postural stability; the direction control score for examining directiveness of COP excursions; the on-axis velocity differences for level of velocity control; and the number of judgments; perceived and true reaching distances; the discrepancy between perceived and true reaching distances, as well as the movement time; the maximum COP distance in anterior-posterior (AP) direction; and the maximum COP velocity in AP direction were also studied for postural control in bending over to reach and retrieve tasks.
The results showed that compared to the controls, patients with schizophrenia manifested significantly increased anterior-posterior postural sway and had a higher rate of falls in incongruent sensory conditions, and exhibited significantly lower utilization of vestibular information to maintain postural stability. Patients with schizophrenia had significant difficulties, both in terms of direction control as well as keeping up with the speed, to coordinate postures and shift weight rhythmically to pursue a reciprocally moving target in the environment. Although patients had demonstrated similar temporal and spatial quality reaching and retrieving objects from the floor compared to controls, they had incorrect internal representation of their own limits of stability. The presentation of a target for retrieval enhanced movement efficiency and increased limit of stability for patients. The correlation between psychiatric symptoms and postural control was limited, while older age was associated with decreased postural stability, direction control, and limit of stability upon object presentation; and the level of CPZE were associated with increased accuracy of internal representation of limits of stability.
In summary, patients with schizophrenia showed significant difficulties in maintaining postural stability as well as controlling postures dynamically to pursue a moving target. They also had difficulties utilizing vestibular information to keep balance, and had incorrect perceptions of their limits of stability. Hence, providing evaluation and intervention on identified areas of postural dysfunction as treatment routines was urged, and directions for intervention were discussed.

References
Ahlgren-Rimpilainen, A., Lauerma, H., Kahkonen, S., Aalto, H., Pyykko, I., Palmgren, K., et al. (2010). Effect of Visual Information on Postural Control in Patients with Schizophrenia. Journal of Nervous and Mental Disease, 198(8), 601-603. doi:10.1097/NMD.0b013e3181ea16bc
Allain, H., Tessier, C., Bentue-Ferrer, D., Tarral, A., Le Breton, S., Gandon, M., et al. (2003). Effects of Risperidone on Psychometric and Cognitive Functions in Healthy Elderly Volunteers. Psychopharmacology (Berl), 165(4), 419-429. doi:10.1007/s00213-002-1272-2
Amado, I., Landgraf, S., Bourdel, M. C., Leonardi, S., & Krebs, M. O. (2008). Predictive Saccades Are Impaired in Biological Nonpsychotic Siblings of Schizophrenia Patients. Journal of Psychiatry and Neuroscience, 33(1), 17-22.
Andreasen, N. C., Paradiso, S., & O'Leary, D. S. (1998). Cognitive Dysmetria as an Integrative Theory of Schizophrenia a Dysfunction in Cortical-Subcortical-Cerebellar Circuitry. Schizophrenia Bulletin, 24(2), 203-218.
Andreasen, N. C., & Pierson, R. (2008). The Role of the Cerebellum in Schizophrenia. Biological Psychiatry, 64(2), 81-88. doi:10.1016/j.biopsych.2008.01.003
Arnfred, S. M., Hemmingsen, R. P., & Parnas, J. (2006). Delayed Early Proprioceptive Information Processing in Schizophrenia. British Journal of Psychiatry, 189, 558-559.
Asslander, L., & Peterka, R. J. (2014). Sensory Reweighting Dynamics in Human Postural Control. Journal of Neurophysiology, 111(9), 1852-1864. doi:10.1152/jn.00669.2013
Barrantes-Vidal, N., Aguilera, M., Campanera, S., Fatjo-Vilas, M., Guitart, M., Miret, S., et al. (2007). Working Memory in Siblings of Schizophrenia Patients. Schizophrenia Research, 95(1-3), 70-75. doi:10.1016/j.schres.2007.06.020
Beckley, D. J., Bloem, B. R., Singh, J., Remler, M. P., Wolfe, N. S., & Roos, R. A. (1991). Postural Reflexes in Patients on Long-Term Neuroleptic Medication. Clinical Neurology & Neurosurgery, 93(2), 119-122.
Bell, M., Milstein, R., Beam-Goulet, J., Lysaker, P., & Cicchetti, D. (1992). The Positive and Negative Syndrome Scale and the Brief Psychiatric Rating Scale. Reliability, Comparability, and Predictive Validity. Journal of Nervous and Mental Disease, 180(11), 723-728.
Bernard, J. A., Dean, D. J., Kent, J. S., Orr, J. M., Pelletier-Baldelli, A., Lunsford-Avery, J. R., et al. (2014). Cerebellar Networks in Individuals at Ultra High-Risk of Psychosis: Impact on Postural Sway and Symptom Severity. Human Brain Mapping, 35(8), 4064-4078. doi:10.1002/hbm.22458
Bloem, B. R., Beckley, D. J., van Vugt, J. P., van Dijk, J. G., Remler, M. P., Langston, J. W., et al. (1995). Long Latency Postural Reflexes Are under Supraspinal Dopaminergic Control. Movement Disorders, 10(5), 580-588.
Bonan, I. V., Colle, F. M., Guichard, J. P., Vicaut, E., Eisenfisz, M., Tran Ba Huy, P., et al. (2004). Reliance on Visual Information after Stroke. Part I: Balance on Dynamic Posturography. Archives of Physical Medicine & Rehabilitation, 85(2), 268-273. doi:10.1016/j.apmr.2003.06.017
Bowie, C. R., Reichenberg, A., Patterson, T. L., Heaton, R. K., & Harvey, P. D. (2006). Determinants of Real-World Functional Performance in Schizophrenia Subjects Correlations with Cognition, Functional Capacity, and Symptoms. American Journal of Psychiatry, 163(3), 418-425.
Brandt, T. (1996). Phobic Postural Vertigo. Neurology, 46(6), 1515-1519.
Brenner, C. A., Lysaker, P. H., Wilt, M. A., & O'Donnell, B. F. (2002). Visual Processing and Neuropsychological Function in Schizophrenia and Schizoaffective Disorder. Psychiatry Research, 111(2-3), 125-136.
Broekema, V., & Rosenbaum, G. (1975). Cutaneous Sensitivity in Schizophrenics and Normals under Two Levels of Proprioceptive Arousal. Journal of Abnormal Psychology, 84(1), 30-35.
Brunnauer, A., Laux, G., Geiger, E., & Möller, H. J. (2004). The Impact of Antipsychotics on Psychomotor Performance with Regards to Car Driving Skills. Journal of Clinical Psychopharmacology, 24(2), 155-160. doi:10.1097/01.jcp.0000116648.91923.82
Bryson, G., & Bell, M. D. (2003). Initial and Final Work Performance in Schizophrenia Cognitive and Symptom Predictors. Journal of Nervous and Mental Disease, 191(2), 87-92.
Caligiuri, M. P., Teulings, H. L., Dean, C. E., & Lohr, J. B. (2015). A Quantitative Measure of Handwriting Dysfluency for Assessing Tardive Dyskinesia. Journal of Clinical Psychopharmacology, 35(2), 168-174.
Cantor-Graae E, I., B, McNeil, TF. (2000). Are Neurological Abnormalities in Schizophrenic Patients and Their Siblings the Result of Perinatal Trunma. Acta Psychiatrica Scandinavica, 101, 142-147.
Carello, C., Grosofsky, A., Reichel, F. D., Solomon, H. Y., & Turvey, M. T. (1989). Visually Perceiving What Is Reachable. Ecological Psychology, 1, 27-54.
Caron, O., Faure, B., & Breniere, Y. (1997). Estimating the Centre of Gravity of the Body on the Basis of the Centre of Pressure in Standing Posture. Journal of Biomechanics, 30(11-12), 1169-1171.
Chang, B. P., & Lenzenweger, M. F. (2005). Somatosensory Processing and Schizophrenia Liability: Proprioception, Exteroceptive Sensitivity, and Graphesthesia Performance in the Biological Relatives of Schizophrenia Patients. Journal of Abnormal Psychology, 114(1), 85-95. doi:10.1037/0021-843X.114.1.85
Chaudhry, H., Bukiet, B., Ji, Z., & Findley, T. (2011). Measurement of Balance in Computer Posturography: Comparison of Methods--a Brief Review. Journal of Bodywork and Movement Therapies, 15(1), 82-91. doi:10.1016/j.jbmt.2008.03.003
Chen, L. S., Rice, T. K., Thompson, P. A., Barch, D. M., & Csernansky, J. G. (2009). Familial Aggregation of Clinical and Neurocognitive Features in Sibling Pairs with and without Schizophrenia. Schizophrenia Research, 111(1-3), 159-166. doi:10.1016/j.schres.2009.03.030
Chen, Y., Palafox, G. P., Nakayama, K., Levy, D. L., Matthysse, S., & Holzman, P. S. (1999). Motion Perception in Schizophrenia. Archives of General Psychiatry, 56, 149-154.
Chern, J. S., Lo, C. Y., Wu, C. Y., Chen, C. L., Yang, S., & Tang, F. T. (2010). Dynamic Postural Control During Trunk Bending and Reaching in Healthy Adults and Stroke Patients. America Journal of Physical Medicine
& Rehabilitation, 89(3), 186-197. doi:10.1097/PHM.0b013e3181c56287
Chevan, J., Atherton, H. L., Hart, M. D., Holland, C. R., Larue, B. J., & Kaufman, R. R. (2003). Nontarget- and Target-Oriented Functional Reach among Older Adults at Risks for Falls. Journal of Geriatric Physical Therapy, 26(2), 22-25.
Choudhury, D., & Savoikar, P. (2011). Seismic Stability Analysis of Expanded Msw Landfills Using Pseudo-Static Limit Equilibrium Method. Waste Management & Research, 29(2), 135-145. doi:10.1177/0734242X10375333
Clementz, B. A., Reid, S. A., McDowell, J. E., & Cadenhead, K. S. (1995). Abnormality of Smooth Pursuit Eye Movement Initiation: Specificity to the Schizophrenia Spectrum? Psychophysiology, 32(2), 130-134.
Corbeil, P., Rodrigue, J., Simoneau, M., Cohen, H., & Pourcher, E. (2012). Influence of Risperidone on Balance Control in Young Healthy Individuals. Psychopharmacology (Berl), 222(1), 59-69. doi:10.1007/s00213-011-2623-7
Cortese, L., Caligiuri, M. P., Williams, R., Schieldrop, P., Manchanda, R., Malla, A., et al. (2008). Reduction in Neuroleptic-Induced Movement Disorders after a Switch to Quetiapine in Patients with Schizophrenia. Journal of Clinical Psychopharmacology, 28(1), 69-73.
Dazzan, P., Lloyd, T., Morgan, K. D., Zanelli, J., Morgan, C., Orr, K., et al. (2008). Neurological Abnormalities and Cognitive Ability in First-Episode Psychosis. Br J Psychiatry, 193(3), 197-202. doi:10.1192/bjp.bp.107.045450
de Groot, M. H., van Campen, J. P., Moek, M. A., Tulner, L. R., Beijnen, J. H., & Lamoth, C. J. (2013). The Effects of Fall-Risk-Increasing Drugs on Postural Control: A Literature Review. Drugs Aging, 30(11), 901-920. doi:10.1007/s40266-013-0113-9
Delevoye-Turrell, Y., Giersch, A., & Danion, J. M. (2003). Abnormal Sequencing of Motor Actions in Patients with Schizophrenia Evidence from Grip Force Adjustments During Object Manipulation. American Journal of Psychiatry, 160(1), 134-141.
Deshmukh, A., Rosenbloom, M. J., & Pfefferbaum, A. (2002). Clinical Signs of Cerebellar Dysfunction in Schizophrenia, Alcoholism, and Their Comorbidity. Schizophrenia Research, 46, 168-174.
Duncan, P. W., Weiner, D. K., Chandler, J., & Studenski, S. (1990). Functional Reach: A New Clinical Measure of Balance. Journal of Gerontology, 45(6), M192-197.
Dworkin, R. H. (1994). Pain Insensitivity in Schizophrenia: A Neglected Phenomenon and Some Implications. Schizophrenia Bulletin, 20(2), 235-248.
Fenton, W. S. (2000). Prevalence of Spontaneous Dyskinesia in Schizophrenia. Journal of Clinical Psychiatry, 61(suppl 4), 10-14.
Fischer, M. H. (2000). Estimating Reachability: Whole Body Engagement or Postural Stability? Human Movement Science, 19, 297-318.
Fong, S. S., Tsang, W. W., & Ng, G. Y. (2012). Taekwondo Training Improves Sensory Organization and Balance Control in Children with Developmental Coordination Disorder: A Randomized Controlled Trial. Research in Developmental Disabilities, 33(1), 85-95. doi:10.1016/j.ridd.2011.08.023
Fourneret, P., Franck, N., Slachevsky, A., & Jeannerod, M. (2001). Self-Monitoring in Schizophrenia Revisited. Cognitive Neuroscience and Neurophysiology, 12(68), 1203-1208.
Franck, N., Farrer, C., Georgieff, N., Marie-Cardine, M., Daléry, J., d’Amato, T., et al. (2001). Defective Recognition of One’s Own Actions in Patients with Schizophrenia. American Journal of Psychiatry, 158(3), 454-459.
Franck, N., Posada, A. s., Pichon, S., & Haggard, P. (2005). Altered Subjective Time of Events in Schizophrenia. The Journal of Nervous and Mental Disease, 193(5), 350-353. doi:10.1097/01.nmd.0000161699.76032.09
Friedman, J. H. (2004). Historical Perspective on Movement Disorders. Journal of Clinical Psychiatry, 65(suppl 9), 3-8.
Frith, C. (2005). The Self in Action: Lessons from Delusions of Control. Consciousness and Cognition, 14(4), 752-770. doi:10.1016/j.concog.2005.04.002
Fujino, H., & Imura, O. (2015). Postural Sway and Clinical Characteristics in Patients with Psychotic Disorders: A Review. Psychiatric Quarterly, 86(4), 603-614. doi:10.1007/s11126-015-9355-5
Gebhardt, S., Hartling, F., Hanke, M., Mittendorf, M., Theisen, F. M., Wolf-Ostermann, K., et al. (2006). Prevalence of Movement Disorders in Adolescent Patients with Schizophrenia and in Relationship to Predominantly Atypical Antipsychotic Treatment. European Child Adolescent Psychiatry, 15(7), 371-382. doi:10.1007/s00787-006-0544-5
Gervin, M., Browne, S., Lane, A., Clarke, M., Waddington, J. L., Larkin, C., et al. (1998). Spontaneous Abnormal Involuntary Movements in First-Episode Schizophrenia and Schizophreniform Disorder: Baseline Rate in a Group of Patients from an Irish Catchment Area. American Journal of Psychiatry, 155(9), 1202-1206.
Gildas Bre´bion, G., Anthony S. David, A. S. H. M., Jones, H. M., & Pilowsky, L. S. (2009). Working Memory Span and Motor and Cognitive Speed in Schizophrenia. Cognitive and Behavioral Neurology, 22(2).
Gopal, S., Liu, Y., Alphs, L., Savitz, A., Nuamah, I., & Hough, D. (2013). Incidence and Time Course of Extrapyramidal Symptoms with Oral and Long-Acting Injectable Paliperidone: A Posthoc Pooled Analysis of Seven Randomized Controlled Studies. Neuropsychiatric Disease and Treatment, 9, 1381-1392. doi:10.2147/NDT.S49944
Gopal, S., Xu, H., Bossie, C., Buron, J. A., Fu, D. J., Savitz, A., et al. (2014). Incidence of Tardive Dyskinesia: A Comparison of Long-Acting Injectable and Oral Paliperidone Clinical Trial Databases. International Journal of Clinical Practice, 68(12), 1514-1522.
Guy, W. (1976). Ecdeu Assessment Manual of Psychopharmcology, Revised. Washington, DC: US DREW publication, Department of Health, Education and Welfare.
Haft, H. (1993). A Methodological Note on Overestimates of Reaching Distance: Distinguishing between Perceptual and Analytical Judgments. Ecological Psychology, 5(3), 255-271.
Haggard, P., Martin, F., Taylor-Clarke, M., Jeannerod, M., & Franck, N. (2003). Awareness of Action in Schizophrenia. Neuroreport, 14(7), 1081-1085. doi:10.1097/01.wnr.0000073684.00308.c0
Hayes, K. C. (1982). Biomechanics of Postural Control. Exercise and Sport Sciences Reviews, 10, 363-391.
Ho, B. C., Mola, C., & Andreasen, N. C. (2004). Cerebellar Dysfunction in Neuroleptic Naive Schizophrenia Patients: Clinical, Cognitive, and Neuroanatomic Correlates of Cerebellar Neurologic Signs. Biological Psychiatry, 55(12), 1146-1153. doi:10.1016/j.biopsych.2004.02.020
Horak, F. B. (1991). Assumptions Underlying Motor Control for Neurologic Rehabilitation. Alexandria, VA: Foundation for Physical Therapy.
Horak, F. B. (2006). Postural Orientation and Equilibrium: What Do We Need to Know About Neural Control of Balance to Prevent Falls? Age and Ageing, 35 Suppl 2, ii7-ii11. doi:10.1093/ageing/afl077
Horak, F. B., & Nashner, L. M. (1986). Central Programming of Postural Movements: Adaptation to Altered Support-Surface Configurations. Journal of Neurophysiology, 55, 1369-1381.
Hwang, S., Agada, P., Kiemel, T., & Jeka, J. J. (2016). Identification of the Unstable Human Postural Control System. Frontiers in Systems Neuroscience, 10, 22. doi:10.3389/fnsys.2016.00022
Ismail, B., Cantor-Graae, E., & McNeil, T. (1998). Neurological Abnormalities in Schizophrenic Patients and Their Siblings. American Journal of Psychiatry, 155, 84-89.
Janno S, Holi M, Tuisku K, & Wahlbeck, K. (2004). Prevalence of Neuroleptic-Induced Movement Disorders in Chronic Schizophrenia Inpatients. American Journal of Psychiatry, 161(1), 160-163.
Janno, S., Holi, M., Tuisku, K., & Wahlbeck, K. (2004). Prevalence of Neuroleptic-Induced Movement Disorders in Chronic Schizophrenia Inpatients. Am J Psychiatry 161:1, January 2004, 161(1), 160-163.
Javitt, D. C., Liederman, E., Cienfuegos, A., & Shelley, A. M. (1999). Panmodal Processing Imprecision as a Basis for Dysfunction of Transient Memory Storage Systems in Schizophrenia. Schizophrenia Bulletin, 25(4), 763-776.
Jeon, H. J., Cho, M. J., Cho, S. J., Kim, S. U., Park, S. K., Kwon, J. S., et al. (2007). Quantitative Analysis of Ataxic Gait in Patients with Schizophrenia: The Influence of Age and Visual Control. Psychiatry Research, 152(2-3), 155-164. doi:10.1016/j.psychres.2006.09.001
Juras, G., Słomka, K., Fredyk, A., Sobota, G., & Bacik, B. (2008). Evaluation of the Limits of Stability (Los) Balance Test. Journal of Human Kinetics, 19, 39-52.
Kao, C. C., & Huang, H. M. (2014). A Comparison of the Quality of Life of Patients with Schizophrenia in Daycare and Homecare Settings. Journal of Nursing Research, 22(2), 126-135.
Kelemen, O., Nagy, O., Matyassy, A., Bitter, I., Benedek, G., Vidnyanszky, Z., et al. (2007). How Well Do Patients with Schizophrenia Track Multiple Moving Targets? Neuropsychology, 21(3), 319-325. doi:10.1037/0894-4105.21.3.319
Kelemen, O., Nagy, O., Matyassy, A., Bitter., I., Benedek, G., Vidnyanszjy, Z., et al. (2007). How Well Do Patients with Schizophrenia Track Multiple Moving Targets? Neuropsychology, 21, 319-325.
Kent, J. S., Hong, S. L., Bolbecker, A. R., Klaunig, M. J., Forsyth, J. K., O'Donnell, B. F., et al. (2012). Motor Deficits in Schizophrenia Quantified by Nonlinear Analysis of Postural Sway. PLoS One, 7(8), e41808. doi:10.1371/journal.pone.0041808
Kessler, R. K., Giovannetti, T., & MacMullen, L. R. (2007). Everyday Action in Schizophrenia: Performance Patterns and Underlying Cognitive Mechanisms. Neuropsychology, 21(4), 439-447. doi:10.1037/0894-4105.21.4.439
Kinney, D. K., Yurgelun-Todd, D., & Woods, B. T. (1999). Neurologic Signs of Cerebellar and Cortical Sensory Dysfunction in Schizophrenics and Their Relatives. Schizophrenia Research, 35, 99-104.
Koreki, A., Tsunoda, K., Suzuki, T., Hirano, J., Watanabe, K., Kashima, H., et al. (2011). Clinical and Demographic Characteristics Associated with Postural Instability in Patients with Schizophrenia. Journal of Clinical Psychopharmacology, 31(1), 16-21. doi:10.1097/JCP.0b013e318205e192
Kozak, K., Ashton-Miller, J. A., & Alexander, N. B. (2003). The Effect of Age and Movement Speed on Maximum Forward Reach from an Elevated Surface: A Study in Healthy Women. Clinical biomechanics, 18(3), 190-196.
Krebs, M. O., Bourdel, M. C., Cherif, Z. R., Bouhours, P., Loo, H., Poirier, M. F., et al. (2010). Deficit of Inhibition Motor Control in Untreated Patients with Schizophrenia: Further Support from Visually Guided Saccade Paradigms. Psychiatry Research, 179(3), 279-284.
Kubota, F., Miyata, H., Shibata, N., & Yarita, H. (1999). A Study of Motor Dysfunction Associated with Schizophrenia Based on Analyses of Movement-Related Cerebral Potentials and Motor Conduction Time. Biological Psychiatry, 45(412), 416.
Kuha, A., Tuulio-Henriksson, A., Eerola, M., Perala, J., Suvisaari, J., Partonen, T., et al. (2007). Impaired Executive Performance in Healthy Siblings of Schizophrenia Patients in a Population-Based Study. Schizophrenia Research, 92(1-3), 142-150. doi:10.1016/j.schres.2007.01.007
Lacour, M., Barthelemy, J., Borel, L., Magnan, J., Xerri, C., Chays, A., et al. (1997). Sensory Strategies in Human Postural Control before and after Unilateral Vestibular Neurotomy. Experimental Brain Research, 115(2), 300-310. doi:10.1007/pl00005698
Le Seac'h, A., Picard, H., Gorsane, M. A., Vidal, P. P., Amado, I., & Krebs, M. O. (2012). A Step toward an Objective Quantification of Subtle Neurological Signs in Schizophrenia. Psychiatry Research, 198(2), 230-234. doi:10.1016/j.psychres.2011.12.039
Lee, J., Poon, L. Y., & Chong, S. A. (2008). Spontaneous Dyskinesia in First-Episode Psychosis in a Southeast Asian Population. Journal of Clinical Psychopharmacology, 28(5), 536-539.
Lenzenweger, M. F. (2000). Two-Point Discrimination Thresholds and Schizotypy: Illuminating a Somatosensory Dysfunction. Schizophrenia Research, 42, 111-124.
Lerner, P. P., Miodownik, C., & Lerner, V. (2015). Tardive Dyskinesia (Syndrome): Current Concept and Modern Approaches to Its Management. Psychiatry and Clinical Neurosciences, 69(6), 321-334.
Leucht, S., Kane, J. M., Kissling, W., Hamann, J., Etschel, E., & Engel, R. (2005). Clinical Implications of Brief Psychiatric Rating Scale Scores. British Journal of Psychiatry, 187, 366-371.
Levy, D. L., Holzman, P. S., & Proctor, L. R. (1983). Vestibular Dysfunction and Psychopathology. Schizophrenia Bulletin, 9(3), 383-438.
Lin, K., Wu, C., & Trombly, C. A. (1998). Effects of Task Goal on Movement Kinematics and Line Bisection Performance in Adults without Disabilities. American Journal of Occupational Therapy, 52, 175-178.
Liston, R. A. L., & Brouwer, B. J. (1996). Reliability and Validity of Measures Obtained from Stroke Patients Using the Balance Master. Archives of Physical Medicine & Rehabilitation, 77, 425-430.
Malenka, R. C., Angel, R. W., Thiemann, S., Weitz, C. J., & Berger, P. A. (1986). Central Error-Correcting Behavior in Schizophrenia and Depression. Biological Psychiatry, 21(3), 263-273.
Malla, A., & Payne, J. (2005). First-Episode Psychosis: Psy-Chopathology, Quality of Life, and Functional Outcome. Schizophrenia Bulletin, 31(3), 650-671.
Manzoni, D. (2005). The Cerebellum May Implement the Appropriate Coupling of Sensory Inputs and Motor Responses: Evidence from Vestibular Physiology. Cerebellum, 4(3), 178-188. doi:10.1080/14734220500193493
Marvel, C. L., Schwartz, B. L., & Rosse, R. B. (2004). A Quantitative Measure of Postural Sway Deficits in Schizophrenia. Schizophrenia Research, 68(2-3), 363-372. doi:10.1016/j.schres.2003.09.003
Matsuura, Y., Fujino, H., Hashimoto, R., Yasuda, Y., Yamamori, H., Ohi, K., et al. (2015). Standing Postural Instability in Patients with Schizophrenia: Relationships with Psychiatric Symptoms, Anxiety, and the Use of Neuroleptic Medications. Gait Posture, 41(3), 847-851. doi:10.1016/j.gaitpost.2015.03.006
McGurk, S. R., Mueser, K. T., Harvey, P. D., LaPuglia, R., & Marder, J. (2003). Cognitive and Symptom Predictors of Work Outcomes for Clients with Schizophrenia in Supported Employment. Psychiatric Services, 54(8), 1129-1135.
Mechri, A., Marie-Chantal, B., Slama, H., Gourion, D., Gaha, L., & Krebs, M. (2009). Neurological Soft Signs in Patients with Schizophrenia and Their Unaffected Siblings: Frequency and Correlates in Two Ethnic and Socioeconomic Distinct Populations. European Archives of Psychiatry Clinical Neuroscience, 259, 218-226.
Melzer, I., Benjuya, N., Kaplanski, J., & Alexander, N. (2009). Association between Ankle Muscle Strength and Limit of Stability in Older Adults. Age and Ageing, 38(1), 119-123. doi:10.1093/ageing/afn249
Morrens, M., Hulstijn, W., & Sabbe, B. (2007). Psychomotor Slowing in Schizophrenia. Schizophrenia Bulletin, 33(4), 1038-1053. doi:10.1093/schbul/sbl051
Nashner, L. M. (2014). Computerized Dynamic Posturography (2nd ed ed.). San Diego: Plural Publishing, Inc.
Nasrallah, H. A. (2005). Neurologic Comorbidities in Schizophrenia. Journal of Clinical Psychiatry, 66 Suppl 6, 34-46.
Overall, J. E., & Gorham, D. E. (1962). The Brief Psychiatric Rating Scale. Psychological Reports, 10, 799-812.
Pappa, S., & Dazzan, P. (2009). Spontaneous Movement Disorders in Antipsychotic-Naive Patients with First-Episode Psychoses: A Systematic Review. Psychological Medicine, 39(7), 1065-1076. doi:10.1017/S0033291708004716
Picard, H., Amado, I., Mouchet-Mages, S., Olie, J. P., & Krebs, M. O. (2008). The Role of the Cerebellum in Schizophrenia: An Update of Clinical, Cognitive, and Functional Evidences. Schizophrenia Bulletin, 34(1), 155-172. doi:10.1093/schbul/sbm049
Picard, H. J., Amado, I., Bourde, M., Landgraf, S., Olie, J., & Krebs, M. (2009). Correlates between Neurological Soft Signs and Saccadic Parameters in Schizophrenia. Progress in Neuro-Psychopharmacology & Biological Psychiatry, 34, 155-172.
Potkin, S. G. (2008). New Advances in the Treatment of Schizophrenia. Introduction. Journal of Clinical Psychopharmacology, 28 (2 Suppl 1), S1-3.
Pradels, A., Pradon, D., Hlavackova, P., Diot, B., & Vuillerme, N. (2013). Sensory Re-Weighting in Human Bipedal Postural Control: The Effects of Experimentally-Induced Plantar Pain. PLoS One, 8(6), e65510. doi:10.1371/journal.pone.0065510
Semkovska, M., Be´dard, M., Godbout, L., Limoge, F., & Stip, E. (2004). Assessment of Executive Dysfunction During Activities of Daily Living in Schizophrenia. Schizophrenia Research, 69((2-3)), 289-300.
Semkovska, M., Stip, E., Godbout, L., Paquet, F., & Bedard, M. A. (2002). Behavioral Disorganization in Schizophrenia During a Daily Activity: The Kitchen Behavioral Scoring Scale. Brain and Cognition, 48(2-3), 546-553.
Sewell, R. A., Perry, E. B., Jr., Karper, L. P., Bell, M. D., Lysaker, P., Goulet, J. L., et al. (2010). Clinical Significance of Neurological Soft Signs in Schizophrenia: Factor Analysis of the Neurological Evaluation Scale. Schizophrenia Research, 124(1-3), 1-12. doi:10.1016/j.schres.2010.08.036
Shergill, S. S., Samson, G., Bays, P. M., Frith, C. D., & Wolpert, D. M. (2005). Evidence for Sensory Prediction Deficits in Schizophrenia. American Journal of Psychiatry, 162, 2384-2386.
Shumway-Cook, A., & Horak, F. B. (1986). Assessing the Influence of Sensory Interaction on Balance: Suggestion from the Field. PHYSICAL THERAPY, 66(10), 1548-1550.
Shumway-Cook, A., & McCollum, G. (1990). Assessment and Treatment of Balance Disorders in the Neurologic Patient. Chattanooga,TN: Chattanooga Corp.
Shumway-Cook, A., & Woollacot, t. M. (2001). Motor Control. Philadelphia: Lippincott Williams & Wilkin.
Spreitzer, L., Perkins, J., & Ustinova, K. I. (2013). Challenging Stability Limits in Old and Young Individuals with a Functional Reaching Task. America Journal of Physical Medicine
& Rehabilitation, 92(1), 36-44. doi:10.1097/PHM.0b013e318269d8f9
Steindl, R., Kunz, K., Schrott-Fischer, A., & Scholtz, A. W. (2006). Effect of Age and Sex on Maturation of Sensory Systems and Balance Control. Developmental Medicine & Child Neurology, 48, 477-482.
Stensdotter, A. K., Loras, H. W., Flovig, J. C., & Djupsjobacka, M. (2013). Postural Control in Quiet Standing in Patients with Psychotic Disorders. Gait Posture, 38(4), 918-922. doi:10.1016/j.gaitpost.2013.04.017
Sullivan, E. V., Rosenbloom, M. J., & Pfefferbaum, A. (2004). Balance and Gait Deficits in Schizophrenia Compounded by the Comorbidity of Alcoholism. American Journal of Psychiatry, 161(4), 751-755. doi:10.1176/appi.ajp.161.4.751
Tadin, D., Kim, J., Doop, M. L., Gibson, C., Lappin, J. S., Blake, R., et al. (2006). Weakened Center-Surround Interactions in Visual Motion Processing in Schizophrenia. Journal of Neuroscience, 26(44), 11403-11412. doi:10.1523/JNEUROSCI.2592-06.2006
Telfer, S., Shivashankar, S., Krishnadas, R., McCreadie, R. G., & Kirkpatrick, B. (2011). Tardive Dyskinesia and Deficit Schizophrenia. Acta Psychiatrica Scandinavica, 124(5), 357-362.
Teng, Y. L., Chen, C. L., Lou, S. Z., Wang, W. T., Wu, J. Y., Ma, H. I., et al. (2016). Postural Stability of Patients with Schizophrenia During Challenging Sensory Conditions: Implication of Sensory Integration for Postural Control. PLoS One, 11(6), e0158219.
Trombly, C. A., & Wu, C. Y. (1999). Effect of Rehabilitation Tasks on Organization of Movement after Stroke. American Journal of Occupational Therapy, 53, 333-344.
Tsunoda, K., Uchida, H., Suzuki, T., Watanabe, K., Yamashima, T., & Kashima, H. (2010). Effects of Discontinuing Benzodiazepine-Derivative Hypnotics on Postural Sway and Cognitive Functions in the Elderly. International Journal of Geriatric Psychiatry, 25(12), 1259-1265. doi:10.1002/gps.2465
Tyldesley, B., & Grieve, J. I. (2002). Muscles, Nerves & Movement: In Human Occuapation (3rd ed. ed.). Malden, MA: Blackwell Science Ltd.
Varambally, S., Venkatasubramanian, G., Thirthalli, J., Janakiramaiah, N., & Gangadhar, B. N. (2006). Cerebellar and Other Neurological Soft Signs in Antipsychotic-Naive Schizophrenia. Acta Psychiatrica Scandinavica, 114(5), 352-356. doi:10.1111/j.1600-0447.2006.00837.x
Venkatasubramanian, G., Latha, V., Gangadhar, B. N., Janakiramaiah, N., Subbakrishna, D. K., Jayakumar, P. N., et al. (2003). Neurological Soft Signs in Never-Treated Schizophrenia. Acta Psychiatrica Scandinavica, 108, 144-146.
Vervoort, G., Nackaerts, E., Mohammadi, F., Heremans, E., Verschueren, S., Nieuwboer, A., et al. (2013). Which Aspects of Postural Control Differentiate between Patients with Parkinson's Disease with and without Freezing of Gait? Parkinson's Disease, 2013, 971480. doi:10.1155/2013/971480
Warren, S., & Ross, R. G. (1998). Deficient Cancellation of the Vestibular Ocular Reflex in Schizophrenia. Schizophrenia Research, 34, 187-193.
Weiden, P. J. (2008). Antipsychotic-Induced Movement Disorders - Forgotten but Not Gone. Acta Psychiatrica Scandinavica, 117(6), 401-402.
Willard, A., & Lueck, C. J. (2014). Ocular Motor Disorders. Current Opinion in Neurology, 27(1), 75-82.
Wu, C., Trombly, C. A., & Lin, K. (1994). The Relationship between Occupational Form and Occupational Performance: A Kinematic Perspective. American Journal of Occupational Therapy, 48(8), 679-687.
Yazıcı, A. H., Demir, B., Yazıcı, K. M., & Göğüş, A. (2002). Neurological Soft Signs in Patients with Schizophrenia and Their Nonpsychotic Siblings. Schizophrenia Research, 58, 241-246.