Thursday-Abstracts

Official Journal of the American College of Sports Medicine
rEsuLTs: Both groups significantly improved between each pre/post trial. The
children improved 0.7007 seconds (p=.00188) and the adults improved .9632 seconds
(p=.00365).
CONCLusIONs: Results show that subjects in this investigation saw positive effects
from physical stimulation on the receptors of the feet. This study suggests that those
experiencing balance deficiencies, such as the elderly population, may benefit from
daily brushings of the feet.
1251 Board #197 May 30, 9:00 AM - 10:30 AM
Concurrent Validity Of Two Postural stability Tests In a
healthy Population
A. Page Glave1 , Jennifer J. Didier1 , Jacqueline Weatherwax1 ,
Casidhe Leonard1 , Sarah Barragan1 , Robert Fiasco1 , Vanessa
Fiaud2 . 1Sam Houston State University, Huntsville, TX. 2West Texas A & M University, Canyon, TX.
(No relationships reported)
The Biodex Balance System Limits of Stability Test (LOS) and Star Excursion Balance
Test (SEBT) are described as measuring dynamic aspects of balance. Practitioners
tend to base test choice on their assessment of face validity in relation to the desired
outcome. This is commonplace with psychomotor testing, but it is important to
establish concurrent validity to ensure the same construct is being assessed.
PurPOsE: To examine concurrent validity of LOS and SEBT.
METhOds: Healthy adult participants (n = 31) were randomly assigned to different
testing orders to randomize the order of tests within the LOS and SEBT tests. LOS
was tested under more stable (12) and less stable (6) conditions using the moderate
setting. SEBT was tested on the right and left legs. Following practice, three trials
were obtained on both tests. LOS scores were averaged using the system protocol,
which does not control for height in dynamic tests. Outliers were eliminated for SEBT
scores and scores were averaged. SEBT directions were offset by 180o to approximate
similar movement patterns to LOS direction. The ipsilateral leg score was used for
the diagonal and frontal directions; bilateral scores were combined for the anterior
and posterior directions on the SEBT. Subjects’ height affects balance, thus partial
correlations were used to examine the relationship between SEBT and LOS while
controlling for height. SAS 9.2 was used to analyze the data.
rEsuLTs: Height was directly related to all directions for SEBT (r = 0.53 – 0.59, p
< .01) and inversely related to some directions for LOS (6: right – r = -0.41, back – r
= -0.41, back left – r = -0.36; 12: front – r = -0.39, back left – r = -0.53; all p ≤ .05).
There were no significant partial correlations between SEBT and LOS scores. Partial
correlations were negative for all directions between SEBT and LOS except for 270o
and right at a platform setting of 12 on the LOS (rSEBT, LOS. H = 0.09, p = .71).
CONCLusIONs: It appears the SEBT and LOS assess different balance constructs,
though both involve dynamic balance. Using these tests could identify different
balance deficiencies and/or potential injury risks. Additional research is needed to
determine and define what specific constructs of balance are being assessed.
1252 Board #198 May 30, 9:00 AM - 10:30 AM
Effect of Water Immersion and Jet resistance on Postural
sway
Matt Baldwin, Talin Louder, Breanna Studenka, Eadric Bressel.
Utah State University, Logan, UT.
(No relationships reported)
Assessment of postural sway or balance is a common practice in athletic rehabilitation
and special populations. Researchers have postulated that water immersion has an
effect on balance due to buoyancy, in part, but the extent of this effect has not been
determined.
PurPOsE: To quantify the effect of water depth and water jet intensity on measures
of postural sway.
METhOds: Ten healthy participants (female = 5, male = 5: Age = 24.1 ± 3.6 years;
weight = 721.5 ± 222.6 N) volunteered for the study. Postural sway measurements
were collected using a waterproof force plate (20 Hz) as participants stood quietly for
90 s, with eyes open, in a double support stance under the following conditions: Land
and water immersion at the level of the greater trochanter (GT) and xiphoid (XI). At
the xiphoid water depth, participants were also perturbed by underwater jets at three
intensities (20%, 40%, and 60%). The area covered by the trajectory of the center of
pressure was computed as a 95% confidence ellipse which served as the dependent
measure in the study. The effect of water depth and jet intensity on the 95% ellipse was
determined using repeated-measures ANOVA with follow-up comparisons.
rEsuLTs: There was a significant main effect (F = 36.68, p = 0.0001) and followup
comparisons revealed that the 95% ellipse area was greater for GT and XI depths
(6.76 ± 4.31 cm2 and 13.4 ± 5.14 cm2, respectfully) when compared to land (3.13 ±
2.48 cm2). Differences were also observed across jet intensities (20% = 14.81 ± 4.98
cm2, 40% = 32.67 ± 10.55 cm2, 60% = 76.65 ± 24.42 cm2, p = 0.003 - 0.026) except
between the 0%/xiphoid condition and the 20%/xiphoid condition (p = 0.530).
CONCLusION: Water immersion and jet intensity have a significant effect on
balance. Based on the results of this study, balance becomes progressively more
challenging with increasing water depth and jet intensity. However, no significant
change was observed when comparing no jet resistance to 20% jet intensity. Therefore,
Vol. 45 No. 5 Supplement S241
in clinical applications where desired functional outcomes include improvement in
postural stability, water immersion to the XI and jet intensities at or above 40% may be
more effective than land therapies in stimulating postural sway.
1253 Board #199 May 30, 9:00 AM - 10:30 AM
Familiarization Trial Needed When Measuring Postural
sway with a Mobile device
Carina A. Staab, Elizabeth J. Epps, Jeremy A. Patterson,
FACSM. Wichita State University, Wichita, KS.
(No relationships reported)
The latest Smartphone’s have built-in motion sensors called a tri-axis accelerometer.
One of the clinical measures that can take advantage of this technology is balance
assessment. Previous studies assessing balance show the need for familiarization.
PurPOsE: The purpose of this study was to determine if a familiarization test was
needed when using Smartphone devices to measure balance.
METhOds: 49 healthy individuals (18 male, 31 female; 23.1±2.6 years) performed a
bilateral, tandem, and single leg balance tests. A barefoot familiarization was recorded
for the 3 stances, and then follow-up testing was done in barefoot, five-toed shoes, and
athletic shoes. All trials consisted of 10-second measures with eyes closed and were
random in order. A commercially available Smartphone was used to determine postural
sway. One trial was completed for each test with an average of 4-minute rest between
trials.
rEsuLTs: Significant differences were demonstrated between familiarization and
each of the assessments that followed (barefoot p=0.007; five-toed shoes p=0.023;
athletic shoe p=0.028). No differences were observed between barefoot and five-toed
shoes (p=0.576), barefoot and athletic shoes (p=0.521), or five-toed shoes and athletic
shoes (p=0.901).
CONCLusION: Outcomes of this study show that balance data measured with a
mobile device requires a familiarization trial. This is in agreement with previous
publications using laboratory based balance assessment equipment and shows that
familiarization is necessary when assessing balance regardless of equipment used.
This may also suggest good consistency with Smartphone technology but should to be
studied further.
1254 Board #200 May 30, 9:00 AM - 10:30 AM
Influence Of age On Balance Initiation
Karen Roemer 1 , Stephanie Hamilton 2 , Louisa Raisbeck 2 .
1 Central Washington University, Ellensburg, WA. 2 Michigan
Technological University, Houghton, MI.
(No relationships reported)
Single Leg Stance (SLS) is often used as a test in clinical settings to assess balance
disorders and risk of falling in various age groups (Berg, 1989; Jonsson et al., 2004).
Establishing the SLS requires controlled transfer of weight from one base of support
to another, which has been shown to deteriorate with age for various activities such as
gait, unrestricted stance, or sit-to-stand movements (Jonsson et al., 2007; Prado et al.,
2011). Little is known about the age related effects on the early phase of establishing
a SLS.
PurPOsE: This study aims to investigate the effect of age on the early phase of
balance initiation during a SLS.
METhOds: Twenty-three subjects (Y: n=15, Mean + SD; Age= 22.5 + 3.4; Wt= 63.2
+ 10.5 kg; Ht = 168.9 + 9.3 cm; O: Y: n=8, Mean + SD; Age= 67.6 + 4.1; Wt= 63.2 +
13.9 kg; Ht = 162.6 + 10.4 cm) who were considered healthy with no previous injuries
or history of falls performed a SLS on a force plate. Subjects were instructed to stand
behind the force plate and to perform a step onto the force plate to establish SLS
and maintain it for 15 seconds. The first second of SLS (initiation) and the next two
seconds (maintenance) were analyzed. Dependent variables: maximum and average
sway velocity, sway area, semi-major and semi-minor axes of the sway area. Variables
were analyzed for the dominant leg. Leg dominance was determined using the balance
recovery test. One-way ANOVA was used to identify differences between Y and O.
rEsuLTs: O compared to Y showed significantly increased values for average sway
velocity (O: 18.9±7.2cm/s, Y: 13.1 ±3.2cm/s, p=0.015) in the initial phase and in the
maintenance phase for average sway velocity (O: 12.5±4.8cm/s , Y: 6.1 ±2.1cm/s,
p