Similar planning strategies for whole-body and arm movements performed in the sagittal plane

The present paper looks for kinematic similarities between whole-body and arm movements executed in the sagittal plane. Eight subjects performed sit-to-stand (STS) and back-to-sit (BTS) movements at their preferred speed in the sagittal plane. Kinematics analysis focused on shoulder motion revealed that STS was composed of a straight, forward displacement followed by a curved, upward displacement while BTS was characterized by a curved, downward and straight, backward displacement. Curvature of the upward displacement was significantly greater than the downward one. Analysis of shoulder-velocity profiles showed that movement duration was significantly longer for BTS compared with STS and that the shape of the velocity profiles changed when subjects performed an STS compared with a BTS movement. Velocity profiles of the upward and downward displacements also differed; the relative acceleration duration (acceleration duration divided by movement duration during the vertical motion) was smaller for the upward compared with the downward displacement. The present results are in accordance with previous findings concerning the execution of vertical arm movements and suggest that the CNS uses similar motor plans for the performance of arm and whole-body movements in the sagittal plane.

[1]  Alexander Grishin,et al.  Investigating centre of mass stabilisation as the goal of posture and movement coordination during human whole body reaching , 2000, Biological Cybernetics.

[2]  Y. Pai,et al.  Control of body mass transfer as a function of speed of ascent in sit-to-stand. , 1990, Medicine and science in sports and exercise.

[3]  K. Kerr,et al.  Analysis of the sit-stand-sit movement cycle in normal subjects. , 1997, Clinical biomechanics.

[4]  C. Atkeson,et al.  Kinematic features of unrestrained vertical arm movements , 1985, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[5]  Robertw . Mann,et al.  Whole-body movements during rising to standing from sitting. , 1990, Physical therapy.

[6]  T. Pozzo,et al.  Evidence of a preprogrammed deactivation of the hamstring muscles for triggering rapid changes of posture in humans. , 1997, Electroencephalography and clinical neurophysiology.

[7]  G. Cheron,et al.  Distinct multi-joint control strategies in spastic diplegia associated with prematurity or Angelman syndrome , 2001, Clinical Neurophysiology.

[8]  G. Schöner,et al.  Effects of varying task constraints on solutions to joint coordination in a sit-to-stand task , 2001, Experimental Brain Research.

[9]  Francesco Lacquaniti,et al.  Early emergence of temporal co-ordination of lower limb segments elevation angles in human locomotion , 2001, Neuroscience Letters.

[10]  T. Pozzo,et al.  Hand trajectories of vertical arm movements in one-G and zero-G environments Evidence for a central representation of gravitational force , 1998, Experimental Brain Research.

[11]  Charalambos Papaxanthis,et al.  Effects of movement direction upon kinematic characteristics of vertical arm pointing movements in man , 1998, Neuroscience Letters.

[12]  J McIntyre,et al.  Reference frames and internal models for visuo-manual coordination: what can we learn from microgravity experiments? , 1998, Brain Research Reviews.

[13]  M. Flanders,et al.  Force path curvature and conserved features of muscle activation , 1996, Experimental Brain Research.

[14]  Alain Berthoz,et al.  The sensorimotor and cognitive integration of gravity , 1998, Brain Research Reviews.

[15]  T. Pozzo,et al.  Standing up from a chair as a dynamic equilibrium task: a comparison between young and elderly subjects. , 2000, The journals of gerontology. Series A, Biological sciences and medical sciences.

[16]  Annie Vinter,et al.  The representation of gravitational force during drawing movements of the arm , 1998, Experimental Brain Research.

[17]  Martin Faint,et al.  Does the brain model newton’s laws? , 2001 .