手功能是一項達成獨立生活的基本卻也是十分複雜的能力，對思覺失調症個案來說，手功能不僅影響日常生活參與、工作效率、且造成生活品質下降。根據動作控制理論，有效率的動作功能需依賴有良好整合之前饋及反饋迴路，且手部的感覺動作因子在反饋迴路中為不可或缺的能力，然而，回顧過去研究，尚缺乏了解感覺動作能力對於手功能的貢獻程度。因此，本篇研究目的在於，以感覺動作控制為基礎，探討思覺失調症的手功能表現。本研究共招募27位慢性期思覺失調症之受試者，所有受試者同時參與社區復健。使用普渡插板測驗及Valpar 8 裝配模擬工作樣本代表手功能表現，以圖像化之個人與社會功能自我評估量表代表整體功能表現，及使用西門－韋恩斯坦單絲測試、抓握提舉測試、操作型感覺測試工具來代表個案不同的感覺動作參數，並由有經驗之精神科醫師評估臨床整體評量表-嚴重度及錐體外徑症狀評量表，了解受試者症狀嚴重度及殘存藥物副作用的情況。以皮爾森積差相關係數分析感覺動作與手功能及功能性表現間的相關性，以多元線性迴歸探討感覺動作表現是否能成為手功能的預測因子。本研究結果發現，除了感覺閾值外，思覺失調症個案之手功能及感覺動作能力皆較健康常模差。相關性結果中發現，操作型感覺測試工具與普渡插版測驗及Valpar 8 裝配模擬工作樣本呈顯著相關，抓握提舉測試與Valpar 8 裝配模擬工作樣本呈顯著相關，顯示感覺動作能力與手功能有一定的相關性。於線性迴歸中發現手功能測驗分別對應不同的預測因子列舉如下，於操作型感覺測試工具中，辨物覺分測驗為普渡插板測驗中的慣用手分測驗及Valpar 8裝配模擬工作樣本之共同預測因子；錐體外徑症狀評量表及操作型感覺測試工具中之重量覺分測驗為普渡插板之組裝分測驗之預測因子。研究結果顯示，感覺動作參數為影響手功能的關鍵能力，特別是辨物覺與重量覺，另外，因藥物引起之副作用及發病年數皆影響手功能表現。此研究結果可供臨床從業人員針對思覺失調症手功能評估及介入時參考及應用。

Hand function is a basic but complicated ability for handling independent living. For people with schizophrenia, hand function not only influences daily life participation and work efficiency, but leads to a decline in quality of life. According to the motor control theory, an efficient motor performance heavily depends on a well-executed feed-forward and feedback control loop. Moreover, the sensorimotor performance is an indispensable element in the feedback control loop. However, rare studies investigated the contribution of sensorimotor ability to hand functions in modern clinical practices, especially in the targeted area of schizophrenia. Therefore, this study aimed to explore the hand functions in people with schizophrenia based on the perspectives of sensorimotor control capabilities. Twenty-seven subjects with schizophrenia in the chronic stage were enrolled in this study. All the subjects have joined in the community rehabilitation program provided by a medical center. The subjects were asked to complete the assessments, including the Purdue Pegboard test (PPT) and the Valpar 8 Simulated Assembly work assessment (Valpar 8) to represent their hand functions; using the Self-Reported Graphic version of the Personal and Social Performance Scale (SRGPSP) to represent functionality; and adopting the Semmes Weinstein Monofilaments (SWM), Pinch-holding-up-activity test (PHUA) and Manual Tactile Test (MTT) to represent the sensorimotor parameters of hands. The experienced psychiatrists evaluated the Clinical Global Impression-Severity (CGI-S) and Extrapyramidal Symptom Rating Scale (ESRS) to grade the illness severity and side effect of drugs. Pearson correlation coefficient was used to analyze the correlation between hand function, functionality, and sensorimotor capability. A multiple linear regression analysis was used to clarify the determinants of hand function of those participants with schizophrenia. The results indicated that not only hand functions but sensorimotor capabilities in people with schizophrenia were worse than healthy population except the sensory threshold measured by SWM. Moreover, the sensorimotor capacities assessed by the MTT and PHUA were correlated significantly with statistical significance to the hand functions evaluated by the PPT and Valpar 8. These findings indicated that sensorimotor abilities of hands might have a certain association with hand function. The results of the regression analysis showed that stereognosis subtest of MTT was the determinant of the dominant subtest of PPT and Valpar 8. The results of ESRS and barognosis subtest of MTT are the determinants of results of assembly subtest of PPT.
These findings indicated that the sensorimotor capacities might be the crucial determinants, especially the stereognosis and barognosis, which influence hand functional performances in people with schizophrenia. In addition, the results also revealed that the side effect of drugs and duration of illness could directly affect hand function. Based on these findings, clinical practitioners should consider sensorimotor performance during assessment of hand or occupational functions and further develop the corresponding intervention program of hand function in people with schizophrenia to respond to the vocational or life needs.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (DSM-5®): American Psychiatric Pub.
Arnould, C., Bleyenheuft, Y., & Thonnard, J.-L. (2014). Hand functioning in children with cerebral palsy. Frontiers in Neurology, 5, 48.
Bachmann, S., Bottmer, C., & Schröder, J. (2005). Neurological soft signs in first-episode schizophrenia: a follow-up study. American Journal of Psychiatry, 162(12), 2337-2343.
Bai, Y. M., Hsiao, C. Y., Chen, K. C., Huang, K. L., Lee, I. H., Hsu, J. W., . . . Yang, Y. K. (2014). The development of a self-reported scale for measuring functionality in patients with schizophrenia—Self-reported version of the graphic Personal and Social Performance (SRG-PSP) scale. Schizophrenia Research, 159(2-3), 546-551.
Bhatia, T., Agarwal, A., Shah, G., Wood, J., Richard, J., Gur, R. E., . . . Deshpande, S. N. (2012). Adjunctive cognitive remediation for schizophrenia using yoga: An open, non-randomised trial. Acta neuropsychiatrica, 24(2), 91-100.
Bitter, F., Hillier, S., & Civetta, L. (2011). Change in dexterity with sensory awareness training: A randomised controlled trial. Perceptual and Motor Skills, 112(3), 783-798.
Bleuler, E. (1911). Dementia praecox: Oder Gruppe der Schizophrenien: F. Deuticke.
Busner, J., & Targum, S. D. (2007). The clinical global impressions scale: Applying a research tool in clinical practice. Psychiatry (Edgmont), 4(7), 28.
Carment, L., Dupin, L., Guedj, L., Térémetz, M., Krebs, M.-O., Cuenca, M., . . . Lindberg, P. G. (2019). Impaired attentional modulation of sensorimotor control and cortical excitability in schizophrenia. Brain, 142(7), 2149-2164.
Chen, L. J., Hao, J. C., Ku, P. W., & Stubbs, B. (2018). Prospective associations of physical fitness and cognitive performance among inpatients with Schizophrenia. Psychiatry Research, 270, 738-743.
Chiu, H. Y., Hsu, H. Y., Kuo, L. C., Chang, J. H., & Su, F. C. (2009). Functional sensibility assessment. Part I: Develop a reliable apparatus to assess momentary pinch force control. Journal of Orthopaedic Research, 27(8), 1116-1121. doi:10.1002/jor.20859
Chiu, H. Y., Hsu, H. Y., Kuo, L. C., Su, F. C., Yu, H. I., Hua, S. C., & Lu, C. H. (2014). How the impact of median neuropathy on sensorimotor control capability of hands for diabetes: An achievable assessment from functional perspectives. PloS One, 9(4), e94452.
Chouinard, G., & Margolese, H. C. (2005). Manual for the extrapyramidal symptom rating scale (ESRS). Schizophrenia Research, 76(2-3), 247-265.
Christopherson, B., & Hayes, P. (2006). Vaplar component work samples uses in allied health. Valpar International Corporation, Tucson.
Chrobak, A. A., Krupa, A., Dudek, D., & Siwek, M. (2021). How soft are neurological soft signs? Content overlap analysis of 71 symptoms among seven most commonly used neurological soft signs scales. Journal of Psychiatric Research, 138, 404-412.
Chuang, W. F., Hwang, E., Lee, H. L., & Wu, S. L. (2015). An in-house prevocational training program for newly discharged psychiatric inpatients: Exploring its employment outcomes and the predictive factors. Occupational Therapy International, 22(2), 94-103. doi:10.1002/oti.1388
Cohn, J. (1988). Statistical power analysis for the behavioral sciences. Lawrence Earlbam Associates, Hillsdale, NJ.
Costantini, M., Salone, A., Martinotti, G., Fiori, F., Fotia, F., Di Giannantonio, M., & Ferri, F. (2020). Body representations and basic symptoms in schizophrenia. Schizophrenia Research, 222, 267-273.
Dahl, T. H. (2002). International classification of functioning, disability and health: An introduction and discussion of its potential impact on rehabilitation services and research. Journal of Rehabilitation Medicine, 34(5), 201-204.
Dazzan, P., & Murray, R. M. (2002). Neurological soft signs in first-episode psychosis: a systematic review. The British Journal of Psychiatry, 181(S43), s50-s57.
Duruöz, M. T. (2014). Assessment of Hand Functions. In M. T. Duruöz (Ed.), Hand Function: A Practical Guide to Assessment (pp. 41-51). New York, NY: Springer New York.
Falk-Kessler, J., & Bear-Lehman, J. (2003). Hand function in persons with chronic mental illness: A practice concern. Occupational therapy in mental health, 19(1), 61-67.
Flyckt, L., Sydow, O., Bjerkenstedt, L., Edman, G., Rydin, E., & Wiesel, F.-A. (1999). Neurological signs and psychomotor performance in patients with schizophrenia, their relatives and healthy controls. Psychiatry Research, 86(2), 113-129.
Folstein, M. F., Folstein, S. E., & McHugh, P. R. (1975). “Mini-mental state”: A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12(3), 189-198.
Gordon, A. M., Westling, G., Cole, K. J., & Johansson, R. S. (1993). Memory representations underlying motor commands used during manipulation of common and novel objects. Journal of Neurophysiology, 69(6), 1789-1796.
Granholm, E., Holden, J. L., Mikhael, T., Link, P. C., Swendsen, J., Depp, C., . . . Harvey, P. D. (2020). What do people with schizophrenia do all day? Ecological momentary assessment of real-world functioning in schizophrenia. Schizophrenia Bulletin, 46(2), 242-251.
He, H., Yang, M., Duan, M., Chen, X., Lai, Y., Xia, Y., . . . Yao, D. (2018). Music Intervention Leads to Increased Insular Connectivity and Improved Clinical Symptoms in Schizophrenia. Frontiers in Neuroscience, 11(744). doi:10.3389/fnins.2017.00744
Hsu, H. Y., Kuan, T. S., Yang, H. C., Tsai, C. L., Yeh, C. H., Lin, C. C., & Kuo, L. C. (2019). Effects of the Surface Texture and Weight of a Pinch Apparatus on the Reliability and Validity of a Hand Sensorimotor Control Assessment. Archives of Physical Medicine and Rehabilitation, 100(4), 620-626.
Hsu, H. Y., Kuo, L. C., Jou, I. M., Chen, S. M., Chiu, H. Y., & Su, F. C. (2013). Establishment of a proper manual tactile test for hands with sensory deficits. Archives of Physical Medicine and Rehabilitation, 94(3), 451-458.
Hsu, H. Y., Kuo, L. C., Kuo, Y. L., Chiu, H. Y., Jou, I. M.,Wu, P. T., & Su, F. C. (2013). Feasibility of a novel functional sensibility test as an assisted examination for determining precision pinch performance in patients with carpal tunnel syndrome. PloS One, 8(8), e72064.
Hsu, H. Y., Kuo, Y. L., Jou, I. M., Su, F. C., Chiu, H. Y., & Kuo, L. C. (2014). Diagnosis from functional perspectives: Usefulness of a manual tactile test for predicting precision pinch performance and disease severity in subjects with carpal tunnel syndrome. Archives of Physical Medicine and Rehabilitation, 95(4), 717-725.
Hsu, H. Y., Lin, C. F., Su, F. C., Kuo, H. T., Chiu, H. Y., & Kuo, L. C. (2012). Clinical application of computerized evaluation and re-education biofeedback prototype for sensorimotor control of the hand in stroke patients. Journal of Neuroengineering and Rehabilitation, 9, 26. doi:10.1186/1743-0003-9-26
Hunter, J. M., Schneider, L. H., Mackin, E. J., & Callahan, A. D. (1990). Rehabilitation of the hand: surgery and therapy. In Rehabilitation of the hand: surgery and therapy (pp. 1258-1258).
Izawa, J., Asai, T., & Imamizu, H. (2016). Computational motor control as a window to understanding schizophrenia. Neuroscience Research, 104, 44-51. doi:10.1016/j.neures.2015.11.004
Janicak, P. G., Marder, S. R., Tandon, R., & Goldman, M. (2014). Schizophrenia: Recent advances in diagnosis and treatment: Springer Science & Business.
Jerosch-Herold, C. (2005). Assessment of sensibility after nerve injury and repair: A systematic review of evidence for validity, reliability and responsiveness of tests. Journal of Hand Surgery, 30(3), 252-264.
Kaneda, Y., Jayathilak, K., & Meltzer, H. Y. (2009). Determinants of work outcome in schizophrenia and schizoaffective disorder: Role of cognitive function. Psychiatry Research, 169(2), 178-179.
Kinnucan, E., Van Heest, A., & Tomhave, W. (2010). Correlation of motor function and stereognosis impairment in upper limb cerebral palsy. The Journal of hand surgery, 35(8), 1317-1322.
Kuo, L. C., Yang, C. J., Lin, C. f., Jou, I. M., Yang, Y. C., Yeh, C. H., . . . Hsu, H. Y. (2019). Effects of a task-based biofeedback training program on improving sensorimotor function in neuropathic hands in diabetic patients: A randomized controlled trial. European Journal of Physical and Rehabilitation Medicine, 55(5), 618-626.
Kurzban, S., Davis, L., & Brekke, J. S. (2010). Vocational, social, and cognitive rehabilitation for individuals diagnosed with schizophrenia: A review of recent research and trends. Curr Psychiatry Rep, 12(4), 345-355. doi:10.1007/s11920-010-0129-3
Lee, P. S., Liu, C. H., Fan, C. W., Lu, C. P., Lu, W. S., & Hsieh, C. L. (2013). The test-retest reliability and the minimal detectable change of the Purdue pegboard test in schizophrenia. Journal of the Formosan Medical Association, 112(6), 332-337. doi:10.1016/j.jfma.2012.02.023
Lee, S. C., Lai, K. Y., & Lee, P. S. (2011). The Study of Relationships between Hand Dexterity and Vocational Performances for Psychiatric Patients in the Community Rehabilitation Centers. Journal of Taiwan Occupational Therapy Research and Practice, 7, 2.
Lehoux, C., Everett, J., Laplante, L., Émond, C., Trépanier, J., Brassard, A., . . . Maziade, M. (2003). Fine motor dexterity is correlated to social functioning in schizophrenia. Schizophrenia Research, 62(3), 269-273.
Lieberman, J. A., & First, M. B. (2018). Psychotic disorders. New England Journal of Medicine, 379(3), 270-280.
Lieberman, J. A., Perkins, D., Belger, A., Chakos, M., Jarskog, F., Boteva, K., & Gilmore, J. (2001). The early stages of schizophrenia: Speculations on pathogenesis, pathophysiology, and therapeutic approaches. Biological Psychiatry, 50(11), 884-897.
Lipskaya-Velikovsky, L., Elgerisi, D., Easterbrook, A., & Ratzon, N. Z. (2019). Motor skills, cognition, and work performance of people with severe mental illness. Disability and Rehabilitation, 41(12), 1396-1402.
Liu, Y. C., Huang, P. C., Lee, Y. C., Chu, C. L., Yang, Y. K., Chen, P. S., & Lin, K. C. (2020). Effects of adding a concurrent cognitive task on manual dexterity in people with schizophrenia: Implications for performance of daily life activities. Asian Journal of Psychiatry, 54, 102456.
Loranger, A. W. (1984). Sex difference in age at onset of schizophrenia. Archives of General Psychiatry, 41(2), 157-161.
Matheson, L. N., Isernhagen, S. J., & Hart, D. L. (2002). Relationships among lifting ability, grip force, and return to work. Physical Therapy, 82(3), 249-256.
Melchior, H., Vatine, J.-J., & Weiss, P. L. (2007). Is there a relationship between light touch-pressure sensation and functional hand ability? Disability and rehabilitation, 29(7), 567-575.
Mendonza, K. S., Palathingal, F., Prasad, S., & Mehrotra, S. (2018). Activities of Daily Living and Instrumental Activities of Daily Living in Patients with Schizophrenia: A Scoping Review. Indian Journal of Public Health Research & Development, 9(10).
Ministry of Health and Welfare. (2018). Report of Disabled People’s Living Condition and Demand Survey 2016.
Morera-Salazar, D. A., Serna-Salazar, A. M., Pérez-Parra, J. E., Agudelo-Cardona, N., Díaz-Restrepo, D., Hurtado-Valencia, M., & Primero-Correa, I. (2021). Postural Control in Schizophrenia: A Retrospective Cohort Study.
Morrens, M., Docx, L., & Walther, S. (2014). Beyond boundaries: In search of an integrative view on motor symptoms in schizophrenia. Frontiers in psychiatry, 5, 145.
Morrens, M., Wouter, H., Van Hecke, J., Peuskens, J., & Sabbe, B. G. C. (2006). Sensorimotor and cognitive slowing in schizophrenia as measured by the Symbol Digit Substitution Test. Journal of Psychiatric Research, 40(3), 200-206.
Mosconi, M. W., Mohanty, S., Greene, R. K., Cook, E. H., Vaillancourt, D. E., & Sweeney, J. A. (2015). Feedforward and feedback motor control abnormalities implicate cerebellar dysfunctions in autism spectrum disorder. Journal of Neuroscience, 35(5).
Murata, J., Murata, S., Hiroshige, J., Ohtao, H., Horie, J., & Kai, Y. (2010). The influence of age-related changes in tactile sensibility and muscular strength on hand function in older adult females. International Journal of Gerontology, 4(4), 180-183.
O'Brien, J. C., & Hussey, S. M. (2017). Introduction to Occupational Therapy: Elsevier - Health Sciences Division.
Ong, H. L., Subramaniam, M., Abdin, E., Wang, P., Vaingankar, J. A., Lee, S. P., . . . Chong, S. A. (2016). Performance of Mini-Mental State Examination (MMSE) in long-stay patients with schizophrenia or schizoaffective disorders in a psychiatric institute. Psychiatry Research, 241, 256-262.
Opheim, A., Danielsson, A., Murphy, M. A., Persson, H. C., & Sunnerhagen, K. S. (2015). Early prediction of long-term upper limb spasticity after stroke: Part of the SALGOT study. Neurology, 85(10), 873-880.
Osborne, K. J., Walther, S., Shankman, S. A., & Mittal, V. A. (2020). Psychomotor Slowing in Schizophrenia: Implications for Endophenotype and Biomarker Development. Biomarkers in Neuropsychiatry, 100016.
Paul, A., Gaokar, P., & Gosavi, N. (2016). An investigation into normative values for fine hand dexterity and its relation with pinch and grip strength among healthy young Indian adults. International Journal of Medical Research & Health Sciences, 5(6), 235-238.
Peluso, M. J., Lewis, S. n. W., Barnes, T. R., & Jones, P. B. (2012). Extrapyramidal motor side-effects of first-and second-generation antipsychotic drugs. The British Journal of Psychiatry, 200(5), 387-392.
Rathod, B., Kaur, A., Basavanagowda, D. M., Mohan, D., Mishra, N., Fuad, S., . . . Heindl, S. E. (2020). Neurological soft signs and brain abnormalities in schizophrenia: a literature review. Cureus, 12(10).
Schwarz, R. J., & Taylor, C. (1955). The anatomy and mechanics of the human hand. Artificial Limbs, 2(2), 22-35.
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(12), 2384-2386.
Shumway-Cook, A., & Woollacott, M. H. (2007). Motor control: Translating research into clinical practice: Lippincott Williams & Wilkins.
Suzuki, T., Uchida, H., Sakurai, H., Ishizuki, T., Tsunoda, K., Takeuchi, H., & Mimura, M. (2015). Relationships between global assessment of functioning and other rating scales in clinical trials for schizophrenia. Psychiatry Research, 227(2-3), 265-269.
Térémetz, M., Carment, L., Brénugat-Herne, L., Croca, M., Bleton, J.-P., Krebs, M.-O., . . . Lindberg, P. G. (2017). Manual Dexterity in schizophrenia—a neglected clinical Marker? Frontiers in psychiatry, 8, 120.
Tiffin, J., & Asher, E. J. (1948). The Purdue Pegboard: Norms and studies of reliability and validity. Journal of Applied Psychology, 32(3), 234.
Tu, I. T., Cheng, Y. S., Mo, P. C., Hsu, H. Y., Kuo, L. C., Jou, I. M., & Su, F. C. (2019). Classifying hand sensorimotor functions of the chronic kidney disease patients using novel manual tactile test and pinch-holding-up activity. PloS One, 14(7).
Vrtunski, P. B., Simpson, D. M., & Meltzer, H. Y. (1989). Voluntary movement dysfunction in schizophrenics. Biological Psychiatry, 25(5), 529-539. doi:10.1016/0006-3223(89)90213-8
Walther, S., & Strik, W. (2012). Motor symptoms and schizophrenia. Neuropsychobiology, 66(2), 77-92.
Wang, S. M., Kuo, L. C., Ouyang, W. C., Hsu, H. M., & Ma, H. I. (2013). A fast-moving target in the Valpar assembly task improved unimanual and bimanual movements in patients with schizophrenia. Disability and Rehabilitation, 35(19), 1608-1613.
Yen, W. J., Kuo, Y. L., Kuo, L. C., Chen, S. M., Kuan, T. S., & Hsu, H. Y. (2014). Precision pinch performance in patients with sensory deficits of the median nerve at the carpal tunnel. Motor Control, 18(1), 29-43.
Yildirim, M. H., Yildirim, E. A., Carpar, E., Coskun, T., Ipekcioglu, D., & Canturk, G. (2018). Hand functions in patients with schizophrenia: A clinical comparison with bipolar disorder and healthy subjects. Comprehensive Psychiatry, 87, 53-58. doi:10.1016/j.comppsych.2018.08.009