Effects of performing dual tasks on postural sway and postural control complexity in people with haemophilic arthropathy.
INTRODUCTION
People with haemophilic arthropathy (PWHA) have impairments in postural control. However, little is known about the effects of demanding conditions, including the unipedal stance and dual tasks, on postural control in PWHA.


AIM
Determine the effects of performing dual tasks while in the one-leg stance on postural sway and postural control complexity in PWHA vs. healthy active (HAG) and non-active (HNAG) groups of individuals.


METHODS
Fifteen PWHA and 34 healthy subjects (18 active and 16 non-active) were recruited. Vertical (V), mediolateral (ML) and anteroposterior (AP) centre of mass signals were acquired using a 3-axis accelerometer placed at the L3/L4 vertebrae of subjects as they performed the one-leg stance under single and dual-task conditions. Sway balance and the complexity of postural control were studied via root mean square (RMS) acceleration and sample entropy, respectively. Increased complexity of postural sway was attributed to increased automatism of postural control.


RESULTS
RMS values for PWHA were higher than HAG under both conditions for the V and ML axes, and higher than HNAG under the dual-task condition for the ML axis. Sample entropy was lower in PWHA than healthy individuals under the dual-task condition for V and ML axes, and the single-task condition for the ML axis (P < .05).


CONCLUSION
PWHA had poorer postural sway and decreased postural control complexity when performing a one-leg stance than healthy people, especially when the dual-task condition was applied. These results may help to design new approaches to assess and improve postural control in PWHA.
['Cruz-Montecinos|Carlos|C|https://orcid.org/0000-0002-3835-3368', 'Carrasco|Juan J|JJ|https://orcid.org/0000-0002-0740-3772', 'Guzmán-González|Benjamín|B|https://orcid.org/0000-0002-5119-5106', 'Soto-Arellano|Verónica|V|https://orcid.org/0000-0002-0015-5219', 'Calatayud|Joaquín|J|https://orcid.org/0000-0002-8670-8346', 'Chimeno-Hernández|Ana|A|https://orcid.org/0000-0002-4449-0174', 'Querol|Felipe|F|', 'Pérez-Alenda|Sofía|S|https://orcid.org/0000-0002-0841-5767']
D000328:Adult D016022:Case-Control Studies D005260:Female D006467:Hemophilia A D006801:Humans D007592:Joint Diseases D008297:Male D004856:Postural Balance D055815:Young Adult
postural control centre of mass sample entropy accelerometry haemophilia motor control