腦中風為腦部血管阻塞或出血造成大腦組織缺乏血液供應而受損，屬於腦部循環異常造成之急性神經功能障礙。中風後所產生之偏癱側上肢與下肢的動作恢復歷程不一，約88％腦中風患者急性期有上肢功能性動作損傷，長期而言仍有55-75％患者存在上肢偏癱問題，嚴重影響日常生活的獨立性。臨床上治療師常以一對一勞力集中方式進行患側肢體評估與治療，且不同治療師對患者的主觀評估與治療處方也存在變異性。本研究目的為設計發展平面式上肢評估訓練平台以探討上肢擺位與施力程度對正常人上肢末端點剛性特徵的影響。

本研究第一階段為設計發展平面式上肢評估訓練平台，包括平台系統理念設計、功能設計、軟硬體選配與整合、及系統校正與整合測試，系統取樣頻率為200Hz；第二階段為臨床應用之前驅研究，探討正常人多關節上肢於不同施力任務期間在不同上肢擺位姿勢對上肢末端點剛性、肩與肘關節力矩之影響。本研究蒐集共十六位正常受試者於十八種(三種上肢擺位，三種施力大小，兩個目標施力方向)定點施力任務下之上肢末端點平面位移與施力變化，以最小平方差法求出末端點剛性矩陣及其相關特徵參數，並配合逆向動力學計算上肢執行目標取向定點施力任務時，肩、肘關節力矩及其關節僵硬度矩陣，所得參數以Kruskal-Wallis Test及Mann-Whitney U Test進行統計分析。

研究結果發現：1)剛性矩陣之K11、K22皆為負值、K12、K21皆為正值；當施力方向相反時，肩、肘關節之力矩會產生正負向之變化；關節僵硬度矩陣之JK11、JK12、JK21、JK22皆為負值，以上參數之表現皆可陳述上肢動作之可能反應；2) 末端點擺位愈靠近肩關節，末端點剛性橢圓長軸愈長；3) 執行X軸向之任務時，擺位愈靠近肩關節，末端點最大剛性軸方向會愈接近施力方向；4)末端點擺位愈靠近肩關節，剛性橢圓形狀愈呈現等向之趨勢。

本研究之未來展望為：1) 因本研究為上肢動態力學分析，若能蒐集更多正常人上肢末端點生物力學特性資料，則可進一步配合使用中央極限定理以建立正常人生物力學特性參數資料庫； 2) 配合臨床醫療人員以本平台系統進行腦中風患者偏癱上肢評估之臨床試驗與研究，期能特徵化腦中風患者上肢末端點異常生物力學量化參數，並輔助傳統治療模式提供中風後單側上肢客觀量化評估及任務取向模式之主動動作訓練，進一步可提供治療師量化評估結果以訂定規劃適合之上肢運動治療處方。

Stroke is defined as sudden death of brain cells when the blood flow to the brain is impaired by infarction or hemorrhage of cerebral arteries. The most common symptom is weakness (hemiparesis) or paralysis (hemiplegia) of one side of the body. Functional impairments of upper limb are always more severe than those of lower limb for deteriorated activities of daily living (ADL). It has been reported that 88％ of the post-strokes suffer from paretic upper limbs in acute stages and 55-75％ of them remain paretic upper limbs after 6 months or more. In clinics, rehabilitation management for post-stroke patients is labor-intensive and the therapeutic are resulted from large inter-therapist variation. This research was aimed to design and develop a 2-D upper-limb endpoint evaluation and rehabilitation training system to investigate biomechanical property of upper limb endpoint stiffness and joint torques.

The first stage of this research was to design/develop 2-D upper-limb endpoint evaluation and rehabilitation training system, including conceptual and functional design, hardware selection/integration, calibration and performance testing. The second stage was to investigate the effects of 3 positions, 3 holding forces, and 2 target directions on endpoint stiffness of upper limbs and joint torques of shoulder and elbow. 16 able-bodied subjects were included in the study. The endpoint displacements and forces were measured and then parameters of endpoint stiffness matrix and ellipse were estimated by least-square method. Joint torques of shoulder and elbow and a 2x2 joint stiffness matrix were determined by inverse dynamics. Kruskal-Wallis test and Mann-Whitney U test were used for statistical analysis.

The results have revealed: 1) K11/K22 of endpoint stiffness matrix were negative, K12/K21 were positive, joint torques of shoulder and elbow were related to reaction of the applied forces, JK11/JK12/JK21/JK22 of joint stiffness matrix were negative ; 2) the above data are quite reasonable for the biomechanical response of upper limb movements ; 3) the longer major axis have resulted from the endpoint closed to shoulder joint; 4) the orientation of ellipse is seemed to be more parallel to the direction of holding force as the endpoint is closer to the shoulder joint; and 5) the shape of ellipse became more isotropic when the endpoint is closer to the shoulder joint.

The future study is recommended: 1) to increase sample size of able-bodies and use central limit theory for establishing database of able-bodies; 2) clinical application of the 2-D upper-limb endpoint evaluation and rehabilitation training system to provide objective and quantitative assessment and movement therapy for stroke patients.

參考文獻
1. O’Sullivan SB, S.T., Physical rehabilitation: Assessment and treatment. 4th ed., p.519-565, 2002, Philadelphia: F.A. Davis Company.
2. http://www.who.int/research/en/
3. Neyer JR, Greenlund KJ, and Denny CH et al., Prevalence of stroke - United States, 2005 (Reprinted from MMWR, vol 56, pg 469-474, 2007). Jama-Journal of the American Medical Association, 2007. 298(3): p. 279-281.
4. Truelsen T, Piechowski-Jozwiak B, and Bonita R et al., Stroke incidence and prevalence in Europe: a review of available data. European Journal of Neurology, 2006. 13(6): p. 581-598.
5. http://www.doh.gov.tw/statistic/index.htm.
6. Sheean G, The pathophysiology of spasticity. European Journal of Neurology, 2002. 9: p. 3-9.
7. http://nawrot.psych.ndsu.nodak.edu.
8. Sawner KA, Lavigne JM, Brunnstroum’s Movement Therapy in Hemiplegia: A Neurophysiological Approach. 2nd ed. 1992, New York: JB Lippincott company.
9. Jack MW, Patrick EC, Biomechanics and Neural control of Posture and Movement. p. 3-124, 2000, New York: Springer-Verlag.
10. Sanes, J.N. and J.P. Donoghue, Plasticity and primary motor cortex. Annual Review of Neuroscience, 2000. 23: p. 393-415.
11. Urton ML, Kohia M, and Davis J et al., Systematic literature review of treatment interventions for upper extremity hemiparesis following stroke. Occupational Therapy International, 2007. 14(1): p. 11-27.
12. Cirstea MC, Ptito A, and Levin MF et al., Arm reaching improvements with short-term practice depend on the severity of the motor deficit in stroke. Experimental Brain Research, 2003. 152(4): p. 476-488.
13. 胡明霞, 動作控制與動作學習. p. P81-211, 2003, 台北: 金名圖書有限股份公司.
14. 徐中盈總編譯, PNF 本體感覺神經肌肉誘發術. p.19-34, 2002, 台北: 合記圖書出版社.
15. Hogan N, Krebs HI, and Sharon A et al., Interactive robotic therapist. 1995, Massachusetts Institute of Technology: USA.
16. Fasoli SE, Krebs HI, and Stein J et al., Robotic therapy for chronic motor impairments after stroke: Follow-up results. Archives of Physical Medicine and Rehabilitation, 2004. 85(7): p. 1106-1111.
17. Burgar CG, Lum PS, and Shor PC et al., Development of robots for rehabilitation therapy: The Palo Alto VA/Stanford experience. Journal of Rehabilitation Research and Development, 2000. 37(6): p. 663-673.
18. Kahn, LE, Zygman ML, and Rymer WZ et al., Robot-assisted reaching exercise promotes arm movement recovery in chronic hemiparetic stroke: a randomized controlled pilot study. Journal of Neuroengineering and Rehabilitation, 2006. 3: p. -.
19. John B, Basic Biomechanics of the Musculoskeletal System. 3rd ed. P.160-161 2001, Philadelphia: Lippincott Williams ＆ Wilkins.
20. Shadmehr R, Wise SP, Computational Neurobiology of Reaching and Pointing: a foundation for motor learning. 2005: Cambridge, Mass: MIT Press.
21. Popescu FC , Rymer WZ, Implications of low mechanical impedance in upper limb reaching motion. Motor Control, 2003. 7(4): p. 323-327.
22. 周威廷, 設計三維震動平臺以探討對腦性麻痺兒童肌肉張力平衡協調的影響. 2003.
23. Vodovnik L, Bowman BR, and Bajd T, Dynamics of Spastic Knee-Joint. Medical & Biological Engineering & Computing, 1984. 22(1): p. 63-69.
24. Zatsiorsky V, Kinetics of Human Motion. p.206-231, 2002, Champaign: Human Kinetics.
25. Svantesson T, Yakahashi, Muscle and tendon stiffness in patients with upper motor neuron lesion following a stroke. European Journal of Applied Physiology, 2000. 82(4): p. 275-279.
26. Mirbagheri MM, Harvest R, Rymer WZ, Mechanical properties of the elbow joint in spastic hemiparetic stroke subjects, in Proceedings of the 2nd Joint EMBS/BMES Conference. 2002: Houston,Tx,USA. p. 2449-2550.
27. Krebs HI, Asien ML, Quantization of continuous arm movements in humans with brain injury. Proceedings of the National Academy of Sciences of the United States of America, 1999. 96(8): p. 4645-4649.
28. Milner TE, Contribution of geometry and joint stiffness to mechanical stability of the human arm. Experimental Brain Research, 2002. 143(4): p. 515-519.
29. Mussaivaldi FA, Hogan N, and Bizzi E, Neural, Mechanical, and Geometric Factors Subserving Arm Posture in Humans. Journal of Neuroscience, 1985. 5(10): p. 2732-2743.
30. Dolan JM, Friedman MB, and Nagurka ML et al., Dynamic and Loaded Impedance Components in the Maintenance of Human Arm Posture. Ieee Transactions on Systems Man and Cybernetics, 1993. 23(3): p. 698-709.
31. Perreault EJ, Kirsch RF, and Crago PE, Multijoint dynamics and postural stability of the human arm. Experimental Brain Research, 2004. 157(4): p. 507-517.
32. Perreault EJ, Kirsch RF, and Crago PE et al., Effects of voluntary force generation on the elastic components of endpoint stiffness. Experimental Brain Research, 2001. 141(3): p. 312-323.
33. Gomi H, Kawato M, Human arm stiffness and equilibrium-point trajectory during multi-joint movement. Biological Cybernetics, 1997. 76(3): p. 163-171.
34. Perreault EJ, Kirsch RF, and Crago PE, Voluntary control of static endpoint stiffness during force regulation tasks. Journal of Neurophysiology, 2002. 87(6): p. 2808-2816.
35. Sinkjaer T, Toft E, and S Andreassen et al., Muscle-Stiffness in Human Ankle
Dorsiflexors - Intrinsic and Reflex Components. Journal of Neurophysiology, 1988. 60(3): p. 1110-1121.