How Does Hearing Impairment Affect Motor Performance?

when stationary, while dynamic balance is maintaining equilibrium when moving. Eyes, ears, physical conditioning, and proprioception are used to help sustain balance [8] and hearing impairment can impede balance and motor function [9,10]. The purpose of this study is to determine if hearing impairment significantly affects balance appraisal tests. ABSTRACT Purpose: Determine if hearing impairment impedes static and dynamic balance. Design: Three hundred subjects, 194 normal hearing (30.2 + 13.8 Yrs) and 106 (30.1 + 14.7 Yrs) hearing-impaired subjects, were administered a battery of 5 balance tests, 3 static and 2 dynamic tests. Analysis: Mann-Whitney non-parametric and one-way ANOVA parametric tests were used to analyze the balance results comparisons between the two groups. Results: Non-parametric Mann-Whitney results indicated significant superior static balance of the normal hearing group in both the dominant and non-dominant leg of the one-leg and stork static balance tests compared to the hearing-impaired group.


Design
Three hundred subjects (300), 173 males and 127 females, were administered a battery of 5 balance tests, 3 static tests and 2 dynamic tests. One hundred and six subjects (106), 64 males and 42 females, reported that they were hearing-impaired in some manner. See Table 1 for the subjects' physical characteristics. The IRB approved study consisted of a convenience sample of 300 subjects. Prior to administering the battery of tests, the subjects were informed of the battery of tests that were to be performed, the description of the tests, and that the subjects could stop at any time during the tests. The subjects signed a consent form prior to the beginning of testing. The tests were conducted by University of New Orleans exercise physiology undergraduate students who were CITI-certified for Human Subjects Testing and trained to administer the battery of balance tests. *-mean + standard deviation.
The battery of tests administered to the subjects consisted of the following tests. Brief descriptions of the tests are also included: [8,[11][12][13][14][15]

One-Leg Standing Balance Static Test (Right and Left Leg)
Stand on 1 leg without holding onto anything. Normal balance is one minute. Subjects scoring less than 30 seconds will need some work.

Stork Balance Static Test (Right and Left Leg)
Place the hands on the hips, position the non-supporting foot against the inside knee of the supporting leg. The subject raises the heel to balance on the ball of the foot. The stopwatch is started as the heel is raised from the floor. The stopwatch is stopped if the hand(s) come off the hips, the supporting foot swivels or moves (hops) in any direction, the non-supporting foot loses contact with the knee, or the heel of the supporting foot touches the floor.
Average time is 25 -39 seconds. Subjects scoring less than 10 seconds are considered to have poor static balance.

Timed Up-and-Go Dynamic Test
A chair is placed against a wall and a spot is measured and marked ten feet from the chair. The test is how long it takes to get up out of the chair, walk 10 feet, turn around, return to the chair and sit back down. If it takes the subject longer than 14 seconds, there is a high risk for falling.

The 5 Times Sit-to-Stand Dynamic Test
Sit in a chair. Whenever ready, stand up and down 5 complete times as fast as possible. Stand fully and sit down with the glutes touching the chair. Subjects without balance problems can do this test in less than 13 seconds.

The Balance Error Scoring System Static Test [16]
There are six positions of the balance error scoring system static test. Three stances (double-leg support, single-leg support,

Limitations
Hearing impairments were self-reported by the participants.
While completing preliminary anthropometric information, participants were asked if they were hearing-impaired. No additional questions were asked about the type or the degree of the hearing impairment.

Analysis
One-way analysis of variance (ANOVA) tests from the IBM   Table 3 for the results.

Discussion
The study revealed that the hearing-impaired group scored significant deficient results in both the dominant and non-dominant legs in the one-leg static test and the stork static test. There were not significant group differences in the Error Scoring static test or in any of the dynamic balance tests. There were also no significant differences regarding the gender, age, height, or weight between the two groups that were analyzed. The question that first comes to mind is why the hearing-impaired group scored so poorly in the one-leg and stork static tests, but not in the An interesting aspect of the study was the high incidence of participants indicating they were hearing -impaired. The initial observation of the anthropometric data suggested that the data reported by the participants was suspect because of the high incidence of hearing impairment in a convenience sample There were 35.3% (106 out of 300) of the study participants that indicated they were hearing-impaired. That seems unusually high from a convenience sample population whose average age was 30.1+14.1 (mean + s.d.) years old; however, the comparative analyses indicating significant static balance differences between the 2 groups indicated that the reported anthropometric data was not suspect. The fact that there were no significant group differences regarding sex, age, height, and weight suggests that the group performance discrepancy was most likely attributed to the hearing-impaired group.

Conclusion
The study demonstrated that hearing impairment negatively impacts static balance and warrants the need for further The high incidence of subjects reporting hearing impairment is a concern and a possible indication of a public health problem.
In future research additional anthropometric information could be gathered from the subject population to determine the type and extent of hearing impairment. The research could possibly identify the major cause of hearing impairment of the research subjects as an environmental one, such as the vestibular disorder of "exposure to noise." If so, the environmental problem could be addressed by devising an action plan to reduce the high incidence of the environmental disorder [4].