Effects of standing and sitting on finger-tapping speed in healthy adults.
METHODS
A repeated-measures design was used to compare finger-tapping performance (hand functional control) across 4 standing and sitting conditions of limb body support postures.


OBJECTIVE
The intent was to examine the hypothesized hemispheric control interference effects of lower limb body support postures on finger-tapping performance. A secondary objective was to gain a better understanding of the relationship between lower limb posture and concurrent finger-tapping activity.


BACKGROUND
In a task such as kicking a ball with the right foot, foot control theory suggests that the left hemisphere contralaterally controls right-foot kicking action. However, it can also be interpreted that the postural support (with the left foot in this example) involving the action of antigravity muscles (leg extensors) is driven ipsilaterally. Based on this explanation, we would expect a hemispheric effect to occur during standing on the left limb while performing a finger-tapping task with the right hand. This study has theoretical and clinical significance for understanding hemispheric and functional control of limbs, which may underlie the assessment of movement control and the development and use of therapeutic interventions that can potentially improve functional movement control.


METHODS
Ninety-eight (98) adult participants (ages 19 to 32 years) performed a finger-tapping task in 4 postural conditions: seated, standing on both feet, standing on the right foot only (RF), and standing on the left foot only (LF).


RESULTS
As predicted, manual performance was significantly slower in the LF condition as compared to the standing and sitting positions. However, when comparing performance between the LF and RF conditions, the difference was minimal.


CONCLUSIONS
Although support for the ipsilateral effect was not found, postural position did influence manual performance.
Gabbard
Carl
C
Department of Health and Kinesiology, Texas A&M University, College Station 77843, USA. c-gabbard@tamu.edu
Hart
Susan
S
D000328:Adult; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005385:Fingers / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*