| Summary: | Under researched somatosensory contributions to postural stability, in addition to high
incident rates of foot injury in the physically active population, lead to two investigative
studies. An initial research study compared variables of two postural stability
assessment devices to determine reliability of outcome measures and commonality of
outcome measures to dynamic postural control. A second study assessed which
measures of postural stability were effective in differentiating between injured persons
using foot orthotics and non-injured persons, and also compared effects of 3-month foot
orthotic usage on measures of postural stability among three groups. In the first study,
23 healthy subjects tested on two separate occasions one-week apart, counterbalancing
the testing order. Intraclass correlation coefficients (ICC) and Pearson product moment
correlations were calculated and analyzed. In the second study, 15 patients diagnosed
with plantar fasciitis or medial arch sprain were given custom orthotics and matched
with 15 non-injured subjects given custom orthotics, and 15 healthy control subjects on
gender, age, height, and body mass index. All 45 subjects were assessed on five
postural stability tests (12 dependent variables) on seven occasions over a four-month
period. Repeated measures MANOVA was employed to evaluate group, time and
interaction effects for the outcome variables (α=0.05). Test-retest reliability, in the
first study, ranged from moderate to high (ICC[subscript 2,1]=0.71 to 0.92) for all outcome
measures. Pearson correlations revealed four statistically significant relationships (p<
.05) between outcome measures (r=0.43 to -0.72). In the second study, nine variables
were entered into repeated measures MANOVA demonstrating significant main and
interaction effects. Post hoc univariate analyses demonstrated six variables with group
main effects and three variables with time main effects. Interaction effects in post hoc
analysis were non-significant. The moderate to high test-retest reliability observed for
outcome measures in the first study is encouraging. Correlations between device
outcome measures, while statistically significant, were low enough to suggest that each
device provided unique information regarding postural stability. Results from the
second study provide strong evidence that foot orthotic wear affects postural stability
over time. The nature of test protocols suggests that functional postural stability testing
aids in assessing effectiveness of foot orthotics. === Graduation date: 2002
|
|---|
