Related Experiment Videos
Does frontal-plane asymmetry in compensatory postural responses represent preparation for stepping?
B E Maki1, R S Whitelaw, W E McIlroy
1Centre for Studies in Aging, Sunnybrook Health Science Centre, University of Toronto, Ont., Canada.
Neuroscience Letters
|January 4, 1993
Summary
Postural responses appear symmetrical but involve hidden frontal plane weight shifts. These shifts are early, modifiable stepping preparations, not fixed motor programs.
Area of Science:
- Human motor control
- Biomechanics
- Neuroscience
Background:
- Bilateral symmetry in feet-in-place postural responses is not well understood.
- Previous research has not fully explored frontal plane asymmetries during postural control.
Purpose of the Study:
- To investigate the symmetry of feet-in-place postural responses in the anterior-posterior direction.
- To identify potential asymmetries in the frontal plane during postural control.
- To explore the relationship between weight shifts and stepping preparations.
Main Methods:
- Subjects experienced postural perturbations in the anterior-posterior direction.
- Analysis focused on feet-in-place responses and compared them to stepping responses.
- Kinematic data were analyzed to assess movement in both sagittal and frontal planes.
Main Results:
- Feet-in-place responses, appearing symmetrical in the sagittal plane, showed significant lateral weight shifts in the frontal plane.
- These lateral weight shifts preceded aborted stepping responses, indicating early preparation.
- Postural strategies varied significantly when viewed in the frontal plane, despite sagittal plane similarity.
Conclusions:
- Compensatory stepping involves discrete, modifiable stages rather than a single motor program.
- Frontal plane analysis reveals hidden asymmetries and distinct postural strategies not apparent in sagittal plane views.
- Lateral weight shifts are crucial, early components of preparatory stepping responses.