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Getting Your Sea Legs.

Stoffregen TA, Chen FC, Varlet M, Alcantara C, Bardy BG - PLoS ONE (2013)

Bottom Line: We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage.Our results revealed rapid changes in postural activity among novices at sea.Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement.

View Article: PubMed Central - PubMed

Affiliation: Affordance Perception-Action Laboratory, University of Minnesota, Minneapolis, Minnesota, United States of America.

ABSTRACT
Sea travel mandates changes in the control of the body. The process by which we adapt bodily control to life at sea is known as getting one's sea legs. We conducted the first experimental study of bodily control as maritime novices adapted to motion of a ship at sea. We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage. In addition, we evaluated the role of the visible horizon in the control of body sway. Finally, we related data on postural activity to two subjective experiences that are associated with sea travel; seasickness, and mal de debarquement. Our results revealed rapid changes in postural activity among novices at sea. Before the beginning of the voyage, the temporal dynamics of body sway differed among participants as a function of their (subsequent) severity of seasickness. Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement. We discuss implications of these results for general theories of the perception and control of bodily orientation, for the etiology of motion sickness, and for general phenomena of perceptual-motor adaptation and learning.

No MeSH data available.


Related in: MedlinePlus

Experiment 2: Mean positional variability of the COP for the AP and ML axes, as a function of days.The figure illustrates the statistically significant interaction between axes and days. The error bars represent standard error of the mean.
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pone-0066949-g005: Experiment 2: Mean positional variability of the COP for the AP and ML axes, as a function of days.The figure illustrates the statistically significant interaction between axes and days. The error bars represent standard error of the mean.

Mentions: For the positional variability of the COP, ANOVA revealed a significant main effect of days, F(1,28)  = 48.75, p<.001, partial η2  = 0.635, which is illustrated in Figure 3. Post hoc tests revealed that Day 0< Day 1 =  Day 2. Consistent with previous studies of experienced maritime crewmembers [17], [18] our novice participants swayed more at sea than when the ship was at the dock. The main effect of target distance conditions was also significant, F(2,56)  = 6.66, p<.015, partial η2  = 0.192. Sway was greater when looking at the nearby target (mean  = 1.47, SD  = 0.13), than when looking at the horizon (mean  = 1.16, SD  = 0.42). There was a significant interaction between the days and target distance factors, F(2,28)  = 37.96, p<.001, partial η2  = 0.576, which is illustrated in Figure 4. At the dock (Day 0), positional variability was greater when looking at the horizon than when looking at the near target, replicating classical effects [31]. At sea, positional variability was greater when looking at the near target. Finally, the day × axis interaction was significant, F(2,56)  = 10.84, p<.001, partial η2  = 0.279 (Figure 5).


Getting Your Sea Legs.

Stoffregen TA, Chen FC, Varlet M, Alcantara C, Bardy BG - PLoS ONE (2013)

Experiment 2: Mean positional variability of the COP for the AP and ML axes, as a function of days.The figure illustrates the statistically significant interaction between axes and days. The error bars represent standard error of the mean.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3686767&req=5

pone-0066949-g005: Experiment 2: Mean positional variability of the COP for the AP and ML axes, as a function of days.The figure illustrates the statistically significant interaction between axes and days. The error bars represent standard error of the mean.
Mentions: For the positional variability of the COP, ANOVA revealed a significant main effect of days, F(1,28)  = 48.75, p<.001, partial η2  = 0.635, which is illustrated in Figure 3. Post hoc tests revealed that Day 0< Day 1 =  Day 2. Consistent with previous studies of experienced maritime crewmembers [17], [18] our novice participants swayed more at sea than when the ship was at the dock. The main effect of target distance conditions was also significant, F(2,56)  = 6.66, p<.015, partial η2  = 0.192. Sway was greater when looking at the nearby target (mean  = 1.47, SD  = 0.13), than when looking at the horizon (mean  = 1.16, SD  = 0.42). There was a significant interaction between the days and target distance factors, F(2,28)  = 37.96, p<.001, partial η2  = 0.576, which is illustrated in Figure 4. At the dock (Day 0), positional variability was greater when looking at the horizon than when looking at the near target, replicating classical effects [31]. At sea, positional variability was greater when looking at the near target. Finally, the day × axis interaction was significant, F(2,56)  = 10.84, p<.001, partial η2  = 0.279 (Figure 5).

Bottom Line: We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage.Our results revealed rapid changes in postural activity among novices at sea.Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement.

View Article: PubMed Central - PubMed

Affiliation: Affordance Perception-Action Laboratory, University of Minnesota, Minneapolis, Minnesota, United States of America.

ABSTRACT
Sea travel mandates changes in the control of the body. The process by which we adapt bodily control to life at sea is known as getting one's sea legs. We conducted the first experimental study of bodily control as maritime novices adapted to motion of a ship at sea. We evaluated postural activity (stance width, stance angle, and the kinematics of body sway) before and during a sea voyage. In addition, we evaluated the role of the visible horizon in the control of body sway. Finally, we related data on postural activity to two subjective experiences that are associated with sea travel; seasickness, and mal de debarquement. Our results revealed rapid changes in postural activity among novices at sea. Before the beginning of the voyage, the temporal dynamics of body sway differed among participants as a function of their (subsequent) severity of seasickness. Body sway measured at sea differed among participants as a function of their (subsequent) experience of mal de debarquement. We discuss implications of these results for general theories of the perception and control of bodily orientation, for the etiology of motion sickness, and for general phenomena of perceptual-motor adaptation and learning.

No MeSH data available.


Related in: MedlinePlus