Task Effects on Three-Dimensional Dynamic Postures during Seated Reaching Movements: An Investigative Scheme and Illustration

Abstract

In this paper we describe a new scheme for empirically investigating the effects of task factors on three-dimensional (3D) dynamic postures during seated reaching movements. The scheme relies on an underlying model that integrates two statistical procedures: (a) a regression description of the relationship between the time-varying hand location and postural angles to characterize the movement data and (b) a series of analyses of variance to test the hypothesized task effects using representative instantaneous postures. The use of this scheme is illustrated by an experiment that examines two generic task factors: hand motion direction and motion completion time. Results suggest that hand motion direction is a significant task factor in determining instantaneous postures, whereas a distinctive difference in the time to complete a motion does not appear to have a significant effect. We discuss the concept of an instantaneous posture and its utility in dynamic studies of movements, some insights into human reaching movement control strategy, and implications for the development of a 3D dynamic posture prediction model.

Get full access to this article

View all access options for this article.

References

Armstrong, W. W. , Green, M. & Lake, R. (1987). Near-real-time control of human figure models. IEEE Computer Graphics and Application, 7, 52–61.

Ayoub, M. M. , & Hsiang, M. S. (1992). Biomechanics simulation of a lifting task. In S. Kumar (Ed.), Advances in industrial ergonomics and safety IV (pp. 831–838). London: Taylor & Francis.

Badler, N. I. , Manoochehri, K. H. , & Walters, G. (1987). Articulated figure positioning by multiple constraints. IEEE Computer Graphics and Applications, 7, 28–38.

Boston, J. R. , Rudy, T. E. , Mercer, S. R. , & Kubinski, J. A. (1993). A measure of body movement coordination during repetitive dynamic lifting. IEEE Rehabilitation Engineering, 1, 137–144.

Burgess-Limerick, R. , Abernethy, B. & Neal, R. J. (1993). Relative phase quantifies interjoint coordination. Journal of Biomechanics, 26, 91–94.

Chaffin, D. B. (1992). Biomechanics modeling for simulation of 3D static human exertions. In M. Manila & W. Karwowski (Eds.), Computer applications in ergonomics, occupational safety and health (pp. 1–11). Amsterdam: North Holland.

Flash, T. (1990). The organization of human arm trajectory control. In J. M. Winters & S. L.-Y. Woo (Eds.), Multiple muscle systems: Biomechanics and movement organization (pp. 282–301). New York: Springer-Verlag.

Flash, T. & Hogan, N. (1985). The coordination of arm movement: An experimentally confirmed mathematical model. Journal of Neuroscience, 7, 1688–1703.

Flash, T. & Mussa-Ivaldi, F. A. (1990). Human arm stiffness characteristics during the maintenance of posture. Experimental Brain Research, 82, 315–326.

10.

Girard, M. (1991). Constrained optimization of artificial animal movement in computer animation. In N. I. Badler , B. A. Barsky , & D. Zeltzer (Eds.), Making them move: Mechanics, control, and animation of articulated figures (pp. 209–232). San Mateo, CA: Morgan Kaufmann.

11.

Hogan, N. (1984). An organizing principle for a class of voluntary movements. Journal of Neuroscience, 3, 2745–2754.

12.

Jung, E. S. , Choe, J. & Kim, S. H. (1994). Psychophysical cost function of joint movement for arm reach posture prediction. In Proceedings of the Human Factors and Ergonomics Society 38th Annual Meeting (pp. 636–640). Santa Monica, CA: Human Factors and Ergonomics Society.

13.

Kaminski, T. & Gentile, A. M. (1986). Joint control strategies and hand trajectories in multijoint pointing movements. Journal of Motor Behavior, 18, 261–278.

14.

Kaminski, T. & Gentile, A. M. (1989). A kinematic comparison of single and multijoint pointing movements. Experimental Brain Research, 78, 547–556.

15.

Karst, G. M. , & Hasen, Z. (1990). Direction-dependent strategy for control of multi-joint arm movement. In J. M. Winters & S. L.-Y. Woo (Eds.), Multiple muscle systems: Biomechanics and movement organization (pp. 268–281). New York: Springer-Verlag.

16.

Kilpatrick, K. E. (1970). Models for the design of manual work station. Unpublished doctoral dissertation, University of Michigan, Arm Arbor.

17.

Marshall, R. N. , Wood, G. A. , & Jennings, L. S. (1985, October). Performance criteria in normal human locomotion. Paper presented at the American Society of Biomechanics 9th Annual Meeting, Ann Arbor, MI.

18.

Morasso, P. (1981). Spatial control of arm movements. Experimental Brain Research, 42, 223–227.

19.

Morasso, P. (1983). Three dimensional arm trajectory. Biological Cybernetics, 48, 187–194.

20.

Morasso, P. & Mussa-Ivaldi, F. A. (1982). Trajectory formation and handwriting: A computational model. Biological Cybernetics, 45, 131–142.

21.

Nelson, W. L. (1983). Physical principles for economies of skilled movements. Biological Cybernetics, 46, 35–147.

22.

Park, K. S. (1973). Computerized simulation model of posture during manual material handling. Unpublished doctoral dissertation, University of Michigan, Ann Arbor.

23.

Phillips, C. B. (1991). Interactive postural control of articulated geometric figures. Unpublished doctoral dissertation, University of Pennsylvania, Philadelphia.

24.

Soechting, J. F. , & Lacquanti, F. (1981). Invariant characteristics of a pointing movement in man. Journal of Neuroscience, 1, 710–720.

25.

Winstein, C. J. , & Garfinkel, A. (1989). Qualitative dynamics of disordered human locomotion: A preliminary investigation. Journal of Motor Behavior, 21, 373–391.