本研究的目的為，在人類步態轉換時，探討雙側下肢關節的運動學因子，包含關節角度，關節角速度及關節角加速度的變化。同時也計算步態轉換時，下肢機械能量的變化。共有十八位身體健康之年輕男性參與本實驗。本實驗包含有，行走，跑步，由走到跑及由跑到走等一系列試驗。
　　首先為了能更進一步解釋由走到跑及由跑到走的變化，先分析走和跑這兩種動作的差異。由量測而得的地面正向反作用力，定位出由走到跑及由跑到走的轉換點。將在轉換點的運動學因子及機械能，與在步態轉換之前時期和步態轉換之後時期做比較。
　　經過統計分析比較後，比較由走到跑及由跑到走這兩種過程，有些運動學因子和下肢機械能呈現相反的趨勢。結果顯示不論由走到跑或由跑到走，在轉換點的一些運動學因子確實有顯著差異，如：膝關節角度、速度及加速度，以及踝關節的角度、速度及加速度。而在轉換點的下肢機械能也呈現出顯著差異。
　　因此，本研究結論為步態轉換為多關節的交互作用而生，並非僅單因某一關節的侷限而導致。至於在轉換點發現的各項因子，是否為引發步態轉換的極限值尚須進一步探討。

　　The purpose of this study was to investigate the kinematic behaviors of bilateral hip, knee and ankle joints in gait transition. The mechanical energy of lower extremity change was also measured in gait transition. Eighteen young males were recruited in this study. A serial of experiments included walking, running, walk-run transition, and run-walk transition.
　　The discrepancy of stable walking and stable running was investigated for further understanding of the gait transition. The transition instants at both walk-run transition and run-walk transition were identified by vertical ground reaction force. The kinematic factors and mechanical energy at transition instant were compared with prior-transition phase and after-transition phase.
　　Results show that a few kinematic behaviors and mechanical energy were opposite between walk-run transition and run-walk transition. The kinematic factors, the angle, velocity, and acceleration of the knee and ankle, showed significant changes at either walk-run transition or run-walk transition, the mechanical energy of single lower extremity also showed significant differences at transition.
　　In conclusion, gait transition would be caused by interactions of multi-joints not only by a single joint. And the mechanical energy was important to illustrate the behavior of gait transition. However, whether the critical values at transition instant reach the ultimate requirement for gait transition should be investigated in depth.

1. Usherwood, J.R. and J.E. Bertram, Gait transition cost in humans. Eur J Appl Physiol, 2003. 90(5-6): p. 647-50.

2. Kao, J.C., S.D. Ringenbach, and P.E. Martin, Gait transitions are not dependent on changes in intralimb coordination variability. J Mot Behav, 2003. 35(3): p. 211-4.

3. Kramer, P.A. and G.G. Eck, Locomotor energetics and leg length in hominid bipedality. J Hum Evol, 2000. 38(5): p. 651-66.

4. Hreljac, A., Preferred and energetically optimal gait transition speeds in human locomotion. Med Sci Sports Exerc, 1993. 25(10): p. 1158-62.

5. Minetti, A.E., L.P. Ardigo, and F. Saibene, The transition between walking and running in humans: metabolic and mechanical aspects at different gradients. Acta Physiol Scand, 1994. 150(3): p. 315-23.

6. Raynor, A.J., et al., Are transitions in human gait determined by mechanical, kinetic or energetic factors? Hum Mov Sci, 2002. 21(5-6): p. 785-805.

7. Turvey, M.T., et al., Can the Transition To and From Running and the Metabolic Cost of Running Be Determined From the Kinetic Energy of Running? J Mot Behav, 1999. 31(3): p. 265-278.

8. Li, L. and J. Hamill, Characteristics of the vertical ground reaction force component prior to gait transition. Res Q Exerc Sport, 2002. 73(3): p. 229-37.

9. Hreljac, A., Determinants of the gait transition
speed during human locomotion: kinematic factors. J Biomech, 1995. 28(6): p. 669-77.

10. Kram, R., A. Domingo, and D.P. Ferris, Effect of reduced gravity on the preferred walk-run transition speed. J Exp Biol, 1997. 200 ( Pt 4): p. 821-6.

11 Beaupied, H., Multon, F., Delamarche, P. Does training have consequences for the walk-run transition speed? Hum Mov Sci, 2003. 22 : p. 1-12

12 Arampatzis, A., Knicker, A., Metzler, V., Brüggemann, G.P. Mechanical power in running: a comparison of different approaches. J Biomech, 2000. 33 : p. 457-463

13 Ho, W.H., Lee C.C., Shiang T.Y., The study of segment of human body of Taiwanese young people from MRI. J Med Biol Eng, 2003. 24(S): s1-s6.

14 Hreljac, A., Arata, A., Ferber, R., et al., An electromoygraphical analysis of the role of dorsiflexion on the gait transition during human locomotion. J Appl Biomech, 2001. 17: p.287-296

15 Saibene, F., Minetti A.E., Biomechanical and physiological aspects of legged locomotion in human. Eur J Appl Physiol, 2003. 88: p. 297-316

16 Li, L., Stability landscapes of walking and running near gait transition speed..
J Appl Biomech, 2000, 16: p.428-435

17 Tseh, W., Bennett, J., Caputo J.L., et al., Comparison between preferred and energetically transition speeds in adolescents. Eur J Appl Physiol, 2002. 88: p. 117-121

18 Kyröläinen, H., Belli, A., Komi, P.V., Biomechanical factors affecting running economy. Med Sci Sports Exerc, 2001 33(28): p 1330-1337.

19 Arampatzis, A., Knicker, A., Metzler, V., Brüggemann, G.P. Influence of 2D and 3D body segment models on energy calculations during kinematic analysis of running. Eur J Appl Physiol, 2002 86: p. 337-341

20 Li, L., van den Bogert, E.C.H., Caldwell, G.E., et al., Coordination patterns of walking and running at similar speed and stride frequency. Hum Mov Sci, 1999. 18 : p. 67-85

21 Winter D.A., Biomechanics and motor control of human movement. 2nd ed. New York: John Wiley & Sons.1990. p119-123

22 Rose J., Gamble J.G., Human walking. 2nd ed. Baltimore: Williams & Wilkins. 1994. p.31

23 Trew M., Everett T., Human movement. 4th ed.
Edinburgh: Churchill Livingstone.
2001. p.180-181