J Korean Phys Ther.  2017 Jun;29(3):135-141. 10.18857/jkpt.2017.29.3.135.

The Effect of the Base of Support on Anticipatory Postural Adjustment and Postural Stability

• Nam HS
• Kim JH
• Lim YJ

• KMID: 2385782
• DOI: http://doi.org/10.18857/jkpt.2017.29.3.135

Abstract

PURPOSE
This study was to identify the anticipatory postural adjustment (APA) mechanism which is represented by the onset time of trunk muscles and the displacement of the center of pressure (COP) according to the different base of support (BOS) during upper extremity movement.
METHODS
Thirty healthy subjects (14 males, 16 females) participated in this study. The movement was performed for 10 trials during each of various BOS (shoulder - width double leg stance, narrow base double leg stance, tandem stance, non-dominant single leg stance) at the 1.2 Hz frequency. Electromyography was used to measure muscle onset time and biorescue was used to measure characteristics of the displacement of COP. Surface bipolar electrodes were applied over the right deltoid anterior, right latissimus dorsi, both rectus abdominis, both internal oblique and both erector spinae. The data were analyzed by repeated one-way ANOVA and Duncan's post hoc test.
RESULTS
The study has revealed following. There were significant differences with muscle onset time in each BOS (p<0.01). There were significant differences in characteristics of the COP in each BOS (p<0.01).
CONCLUSION
The study found that the more narrowed the basis requires the more rapid anticipatory postural control in contralateral postural muscle when the upper extremity movement is performed.

Keyword

Anticipatory postural adjustment (APA); Base of support (BOS); Postural stability; Perturbation

MeSH Terms

Electrodes
Electromyography
Healthy Volunteers
Humans
Leg
Male
Muscles
Rectus Abdominis
Superficial Back Muscles
Upper Extremity