Affiliations: University of Illinois at Chicago, Chicago, IL,
USA
Note: [] Address for correspondence: Alexander Aruin, Ph.D., Department
of Physical Therapy (MC 898), University of Illinois at Chicago, 1919 W Taylor
St (4th floor), Chicago, IL 60612, USA. Tel.: +1 312 355 0904; Fax: +1 312 996
4583; E-mail: aaruin@uic.edu
Abstract: This study investigated the effect that load magnitude, load
location, and the dimensions that the base of support have on postural sway in
standing while wearing a backpack, single strapped bag, briefcase, or purse.
Subjects were instructed to carry a load of 10% or 20% of their body
weight with either their feet spaced shoulder width apart or together for a
period of 45 seconds. Medial/lateral and anterior/posterior center of pressure
(COP) displacement and COP velocity were calculated. Overall, it was found that
an increase in load magnitude produced an increase in postural sway and
velocity of COP. In addition, a large increase in the medial/lateral COP
velocity was observed when subjects carried a briefcase, single strapped bag,
or purse. Additionally, a larger COP sway was recorded in conditions of
standing with decreased base of support (feet together). These findings suggest
the importance of considering the way we carry loads in order not only to place
less strain on the body and to minimize our efforts, but to optimize postural
control as well.
