Walking Attainment in Very Low Birth Weight Infants in Japan

OBJECTIVE

To clarify the corrected age of walking attainment in very low birth weight infants by birth weight and gestational age, and determine perinatal factors affecting the delay in walking attainment.

METHOD

This was a longitudinal study. We investigated walking attainment and perinatal factors in 145 very low birth weight infants without neurological abnormalities (mean birth weight 1019.3 ± 299.7 g, gestational age 29.0 ± 2.9 weeks). The study infants were stratified by birth weight (group A: <1,000 g, group B: 1,000 g≤, <1,500 g) and gestational age (group I: <28 weeks, group II: 28 weeks≤, <37 weeks) and were compared using unpaired t-tests. Furthermore, we examined the perinatal factors that affect the delay in walking attainment using multiple regression analysis.

RESULTS

Of the walking attainment, infants in Group A were older than those in Group B (50th percentile, 15.8 vs. 14.7 months). Infants in Group I were older than those in Group II (50th percentile, 16.0 vs. 14.8 months). Using multiple regression analysis with walking attainment age as the dependent variable, the duration of mechanical ventilation was found to be significantly related.

CONCLUSION

Very low birth weight infants with light weight and short gestational age have delayed walking attainment, and longer duration of mechanical ventilation increases the risk of delay.

Relationships between Gross Motor Abilities and Sensory Processing in Children Aged 18 to 36 Months

OBJECTIVE

We investigated the relationship between gross motor abilities and sensory processing in typically developing children.

METHOD

Participants included children aged 18 to 36 months (N = 48). All participants were full-term infants. We assessed gross motor abilities based on the Gross Motor Function Measure (GMFM), and sensory processing characteristics based on the Infant/Toddler Sensory Profile (ITSP). The gross motor ability index was calculated using GMFM score which was estimated from the age. Pearson's product moment correlation coefficients were used to examine the relationships between the gross motor ability indexes and ITSP section scores.

RESULTS

Our findings showed that gross motor ability may be related to oral sensory processing. The children who were more responsive to oral sensory processing tended to exhibit gross motor abilities below the standard for that age.

CONCLUSION

Gross motor abilities were related with sensory processing, especially oral sensory processing, in children aged 18 to 36 months.

Relevant factors of self-care in children and adolescents with spastic cerebral palsy

Objective

Manual ability is considered one of the factors that can predict functional independence in activities of daily living. For evaluating personal tasks such as self-care, the Pediatric Evaluation of Disability Inventory (PEDI) comprises/introduces/offers a set of useful measures that assist in enhancing the capability for self-care among children and adolescents with cerebral palsy (CP). The aim of this study was to investigate the relevant factors of self-care capability and performance in children and adolescents with spastic CP.

Methods

This was a cross-sectional study. Seventy-six children and adolescents with spastic CP (between 5 and 18 years of age), representing levels I to IV of the Gross Motor Function Classification System-Expanded & Revised version (GMFCS), were analyzed. Multiple linear regression analysis with forward stepwise selection was conducted to examine which determinants were related to self-care capability and performance. Independent variables were age, CP type, GMFCS, Manual Ability Classification System, Box and Block Test, and grip strength in the dominant and non-dominant hands. Dependent variables were scores for the PEDI Functional Skills Scale and the PEDI Caregiver Assistance Scale.

Results

Results of the multiple regression analysis showed that the PEDI Functional Skills scale scores were correlated with the Box and Block Test in the dominant hand and GMFCS (Adjusted R² = 0.69). The PEDI Caregiver Assistance Scale scores were correlated with the Box and Block Test in the dominant hand, GMFCS, and age (adjusted R² = 0.71).

Conclusion

When considering self-care of children and adolescents with spastic CP, it is necessary to consider the evaluation of upper limb dysfunction in addition to GMFCS.

Factors influencing the participation of children with disabilities in the community

[Purpose] To promote community involvement in children, the factors that influence and limit their participation must be well understood. The purpose of this study was to clarify the factors that limit the community participation of children with disabilities. [Participants and Methods] In total, 235 questionnaires were distributed to parents at special support schools, pediatric hospitals, home-visit nursing stations, and after-school daycare services in Tokyo, Gunma, Hiroshima, and Saga prefectures in Japan. Data related to the Participation and Environment Measure for Children and Youth, age, height, weight, gross motor function, presence of medical care, diagnosis, and parental age were recorded for school-aged children. [Results] Multiple regression analysis using the 100 valid questionnaire responses revealed that the number of community activities that the children participated in depended on the children's need for medical care (standardized partial regression coefficient: -0.20). The frequency was affected by gross motor function (standardized partial regression coefficient: -0.24). When respiratory, feeding, and excretion-related medical care were required, the children tended to participate in fewer community activities. [Conclusion] Community participation is influenced by the different factors in each aspect analyzed (number of activities, frequency, and degree of involvement). The factors that should be considered when promoting children's participation in rehabilitation must be identified.

Effects of continued positioning pillow use until a corrected age of six months on cranial deformation and neurodevelopment in preterm infants: A prospective case-control study

BACKGROUND

Preterm infants have a high risk of cranial deformity resulting from external pressures. Such deformity is associated with delayed neurodevelopment.

AIMS

We aimed to clarify the effects of continuous use of positioning pillows on cranial deformity and neurodevelopment in preterm infants.

METHODS

This prospective case-control study was conducted between November 2018 and August 2019. The continuous use of a pillow was initiated after discharge from the neonatal intensive care unit, up to a corrected age of six months. Preterm infants weighing less than 1800 g without neurological abnormalities were included in the study. Patients were divided into two groups: non-pillow group (NP-group) and pillow group (P-group). The primary outcome was the Bayley Scales of Infant Development III (BSID-III) score. We compared asymmetrical cranial deformity and the BSID-III scores in the two groups at a corrected age of six months using the Fisher's exact test and unpaired t-test, respectively.

RESULTS

There were 19 preterm infants (mean gestational age 32.5 ± 1.9 weeks, birth weight 1461.3 ± 244.7) eligible during the study period. The P-group (n = 11) showed asymmetrical cranial deformity at six months less frequently than the NP-group (n = 8) (p = 0.001, Fisher's exact test). Infants in the P-group had significantly higher scores on the BSID-III cognitive scales (95.0 ± 8.4 vs. 86.9 ± 2.6; p = 0.02, unpaired t-test) and fine motor scores on the motor scales (8.6 ± 2.2 vs. 6.6 ± 0.7, p = 0.02, unpaired t-test).

CONCLUSIONS

Continuous pillow use in preterm infants is effective in reducing cranial deformity and improved cognitive and fine motor skills.

TRIAL REGISTRATION

UMIN Clinical Trials Registry, trial no. UMIN000034400 (http://www.umin.ac.jp/ctr/index.htm).

Effects of nutritional status on prognosis in patients with severe hemiplegia who were recently admitted to a rehabilitation hospital

[Purpose] The purpose of this study was to examine the effect of nutritional status on the prognosis of patients with severe hemiplegia who were recently admitted to a convalescent rehabilitation hospital. [Participants and Methods] Eighty patients with stroke and severe hemiplegia were divided into two groups based on their serum albumin levels: normal (serum albumin 3.5 g/dL or more) and undernourished group (serum albumin 3.4 g/dL or less). Background characteristics, cognitive function, neurological symptoms, physical function at admission, and outcome were compared between groups. [Results] There were no differences found between groups in terms of cognitive function, neurological symptoms, physical function at admission, destination, and length of stay at the hospital. In contrast, age and duration from onset to admission were significantly lower in the normal group than in the undernourished group. The ability to walk and perform activities of daily living (ADL) at discharge was significantly higher in the normal group than in the undernourished group. [Conclusion] As a result, the findings of the present study suggest that in patients with severe hemiplegia, nutritional status at the time of admission determines the improved walking and ADL ability at the time of discharge.

Characteristics of dynamic standing balance with and without an insole in patients with spastic diplegia cerebral palsy

[Purpose] This study examined characteristics of dynamic standing balance, with an without an insole, in patients with spastic diplegia cerebral palsy (CP). [Participants and Methods] This cross-sectional study used a crossover design. Eleven patients with spastic diplegia CP and gross motor levels between I and III with spastic diplegia CP (according to the Gross Motor Function Classification System expanded and revised version) were randomly allocated to either the barefoot or insole groups. The Index of postural stability (IPS) was evaluated while each patient was barefoot and while wearing insoles. The Pediatric Evaluation of Disability Inventory (PEDI) was used to measure functional self-care and mobility domains. [Results] While wearing the insoles, the center movement distance between right and left positions was significantly higher. While barefoot, IPS and area of postural sway correlated with the PEDI subscales for mobility and self-care. [Conclusion] Insoles promote standing balance and dynamic balance to move the center of pressure within the base of support. Such improvements may enhance activities of daily living in patients with spastic diplegia CP.

Effects of an underwear-type hip abduction orthosis on sitting balance and sit-to-stand activities in children with spastic cerebral palsy

[Purpose] Hip dislocation and subluxation are common in patients with cerebral palsy (CP). Hip abduction orthoses are used to prevent and treat these problems. This study investigated the effects of an underwear-type hip abduction orthosis on sitting balance and sit-to-stand (STS) activity in children with spastic CP. [Participants and Methods] This trial had a cross-over design. Eight children aged 6 to 18 years old with spastic CP and Gross Motor Function Classification level III and IV were randomly allocated to groups with or without use of the underwear-type hip orthosis. The trunk impairment scale (TIS) score was evaluated and the 5-times sit-to-stand test (FTSST) was conducted with and without the underwear. [Results] The dynamic sitting balance scores in the TIS and FTSST showed significant improvement with use of the orthotic underwear. [Conclusion] The dynamic sitting balance scores of the TIS and FTSST were higher, thus indicating better stability, when wearing the orthosis underwear. Thus, it was suggested that underwear-type hip abduction orthoses are effective for promoting sitting balance and STS activities in children with spastic CP.

A predictor of aerobic threshold for patients with heart failure with reduced ejection fraction

[Purpose] The initial cardiopulmonary response to exercise is hypothesized to be a useful predictor of aerobic threshold in patients with heart failure. This study aimed to evaluate the correlation between aerobic threshold and cardiopulmonary responses to exercise onset by comparing patients with heart failure using preserved (≥50%) and reduced (<50%) left ventricular ejection fractions. [Participants and Methods] Twenty-eight males (age, 36-82 years; 12 with preserved and 16 with reduced left ventricular ejection fractions) underwent a progressive submaximal cardiopulmonary exercise test using a cycle ergometer. The aerobic threshold, time constant, and area under the oxygen uptake curve for the first 4 min (V̇O₂AUC) were determined. [Results] A significant association was observed between aerobic threshold and V̇O₂AUC in the reduced group but not in the preserved group. No significant correlations were found between time constant and V̇O₂AUC or between aerobic threshold and time constant in either group. [Conclusion] The results suggest that V̇O₂AUC measured from exercise onset to an initial 4-min period could provide an easily and safely obtained predictor to assess aerobic capacity in people with reduced left ventricular ejection fractions.

A newly developed floor chair placed on an office chair reduces lumbar muscle fatigue by cyclically changing its lumbar supporting shape

[Purpose] This study investigated lumbar muscle fatigue before and after maintaining a seated position for one hour, lumbar and pelvic inclination angle change, in subjects with and without active lumber support. [Subjects and Methods] Fourteen healthy subjects randomized into two groups sat on a floor chair, placed on an office chair, that cyclically changed its lumbar supporting shape to provide active lumbar support (ALS) or no ALS for one hour. Before and after, we measured the frequency of muscle waveforms of the trunk extensor muscles when the subjects lifted an object weighing 10% of their body weight, using both hands while seated. In addition, ROMt (Range of motion test) of trunk rotation, degree of fatigue and muscle stiffness were analyzed. [Results] Muscle frequency while lifting the weight decreased significantly without ALS compared to with ALS. Mean muscle stiffness increased, ROMt decreased in desk work task significantly without ALS compared to with ALS. [Conclusion] These results suggest that the lumbar muscles became fatigued, because low frequencies, increased muscle stiffness, and decreased ROMt without ALS. We suggest lumbar muscle fatigue was maintained low for subjects seated in a chair with ALS.

Development of a prognostic scale for severely hemiplegic stroke patients in a rehabilitation hospital

OBJECTIVES

For patients with severe hemiplegia in a rehabilitation hospital, early prediction of the functional prognosis and outcomes is challenging. The purpose of this study was to create and verify a prognostic scale in severely hemiplegic stroke patients and allowing for prediction of (1) the ability to walk at the time of hospital discharge, (2) the ability to carry out activities of daily living (ADL), and (3) feasibility of home discharge.

PATIENTS AND METHODS

The study was conducted on 80 severely hemiplegic stroke patients. A prognostic scale was created as an analysis method using the following items: mini-mental state examination (MMSE) at the time of admission, modified NIH stroke scale (m-NIHSS); trunk control test (TCT); and the ratio of the knee extensor strength on the non-paralyzed side to the body weight (KES/BW-US). We verified the reliability and validity of this scale.

RESULTS

We established a prognostic scale using the MMSE, m-NIHSS, TCT, and KES/BW-US. A score of 56.8 or higher on the prognostic scale suggested that the patient would be able to walk and that assistance with ADL would be unnecessary at the time of hospital discharge. In addition, a score of 41.3 points indicated that the patient's return home was feasible. The reliability and the results were in good agreement. These findings showed that the ability or inability to walk was predictable in 85%, the need of assistance with ADL in 82.5%, and the feasibility of home return in 76.3% of cases.

CONCLUSION

At the time of admission, four evaluation items permitted the prediction of three outcomes at time of discharge. Our formula predicts three outcomes with an accuracy of more than 76%.

Reliability and validity of the Japanese version of the selective control assessment of the lower extremity tool among patients with spastic cerebral palsy

[Purpose] The aim of this study was to translate the Selective Control Assessment of the Lower Extremity (SCALE) tool from English to Japanese and to assess the reliability and validity of the Japanese version of the SCALE (SCALE-J) tool in Japanese patients with spastic cerebral palsy. [Subjects and Methods] The SCALE tool was translated into Japanese in accordance with the published guidelines. In total, 55 patients with spastic cerebral palsy were enrolled in the present study. Reliability by internal consistency (Cronbach's α), intrarater reliability, inter-rater reliability, and convergent validity by comparing Gross Motor Function Classification System (GMFCS) scores were examined. [Results] The Cronbach's α value of the SCALE-J tool was 0.97-0.98, whereas that of the intrarater and inter-rater reliability ranged from 0.93 to 0.96. The Spearman correlation coefficient revealed a good relationship between the SCALE tool and the GMFCS. [Conclusion] The SCALE-J tool was found to be reliable and valid; therefore, the SCALE tool may be useful for evaluation in clinical practice.

Impact of loaded sit-to-stand exercises at different speeds on the physiological cost of walking in children with spastic diplegia: A single-blind randomized clinical trial

PURPOSE

In the present study, we aimed to determine whether similarly loaded sit-to-stand exercises at different speeds improve the physiological cost of walking in children with spastic diplegia.

METHODS

This design was a single-blind randomized clinical trial. Sixteen children with cerebral palsy (CP), aged 12-18 years, with a diagnosis of spastic diplegia, were randomly allocated to a slow loaded sit-to-stand exercise group (n=8) and a self-paced loaded sit-to-stand exercise group (n=8). Loaded sit-to-stand exercise was conducted at home for 15min, 4 sets per day, 3-4days per week, for 6 weeks. The patients were evaluated immediately before the intervention and after the training. Lower limb muscle strength using a hand-held dynamometer, selective voluntary motor control using SCALE, 6-min walk distance (6MWD), and Physiological Cost Index (PCI) were measured.

RESULTS

The 6MWD showed a significant difference before and after intervention. PCI showed a significant difference between the two groups and the two time points. 6MWD and the PCI improved after intervention in the slow sit-to-stand exercise group.

CONCLUSIONS

Compared to loaded sit-to-stand exercise at a regular speed, slow low-loaded sit-to-stand exercise improved the 6MWD and PCI in children with CP, suggesting that this decrease in speed during exercise improves the physiological cost of walking in these children.

Relation of selective voluntary motor control of the lower extremity and extensor strength of the knee joint in children with spastic diplegia

[Purpose] The aim of this study was to investigate differences in selective voluntary motor control of the lower extremities by objective assessment and determine the relationship between selective voluntary motor control and knee extensor strength in children with spastic diplegia. [Subjects and Methods] Forty individuals who had spastic cerebral palsy, with Gross Motor Function Classification System levels ranging from I to III, were assessed using the Selective Control Assessment of the Lower Extremity and by testing the maximum knee extensor strength. The unaffected side was defined as the lower limb with the higher score, and the affected side was defined as the lower limb with the lower score. [Results] The Selective Control Assessment of the Lower Extremity score on the affected side had a lower average than that on the unaffected side. The scores showed a significant inverse correlation with the maximum knee extensor strength. [Conclusion] There was bilateral difference in the selective voluntary motor control of the lower extremities in children with spastic diplegia, and the selective voluntary motor control of the lower extremity was related to maximum knee extensor strength.

Joint Function and Arthropathy Severity in Patients with Hemophilia

BACKGROUND

The Arnold-Hilgartner classification is one of the most popular evaluation systems for the progression hemophilic arthropathy. A previous study reported an association between arthropathy severity and arc range of motion (ROM). However, associations between arthropathy severity and angular ROM and muscle strength remain unclear.

AIM

The purpose of this study was to clarify the association between joint function and arthropathy severity in hemophilia.

METHODS

We studied the knee, ankle, and elbow joints of 31 patients with hemophilia (PWH). The condition of the affected joints was evaluated on the basis of the interview data, joint function measurements, and roentgenography of the affected joints. In assessment of joint function, we evaluated knee strength (flexor, extensor) and grip strength as well as the passive ROM of the elbow, knee, and ankle. During the interview, all patients were asked about the history of intra-articular bleeding over the past year and pain.

RESULTS

As arthropathy severity worsened, knee flexor strength, knee extensor strength, grip strength, and ROM (elbow flexion, elbow extension, knee flexion, knee extension, and ankle extension) significantly decreased. Even patients with mild arthropathies experienced knee extensor weakness and extension limitation. In addition, joint function of severe ankle arthropathy was significantly related to the history of intra-articular bleeding and pain.

CONCLUSION

Our results suggest that physical therapy is necessary to improve joint function in PWH and mild or no arthropathy. Pain control and prophylactic hematological management are necessary for patients with severe arthropathy because intra-articular bleeding and pain significantly decrease joint function.

Self-monitoring has potential for home exercise programmes in patients with haemophilia

Haemophiliacs who have had to keep a physically inactive lifestyle due to bleeding during childhood are likely to have little motivation for exercise. The purpose of this study is to clarify the effectiveness of the self-monitoring of home exercise for haemophiliacs. A randomized controlled trial was conducted with intervention over 8 weeks at four hospitals in Japan. Subjects included 32 male outpatients aged 26-64 years without an inhibitor who were randomly allocated to a self-monitoring group and a control group. Individual exercise guidance with physical activity for improvement of their knee functions was given to both groups. The self-monitoring materials included an activity monitor and a feedback system so that the self-monitoring group could send feedback via the Internet and cellular phone. The self-monitoring was performed by checking exercise adherence and physical activity levels, bleeding history and injection of a coagulation factor. Both groups showed significant improvements in exercise adherence (P < 0.001) and physical function such as the strength of knee extension (P < 0.001), range of knee extension (P < 0.001), range of ankle dorsiflexion (P < 0.01), a modified Functional Reach (P < 0.05) and 10 metre gait time (P < 0.01). In particular, improvements in exercise adherence (P < 0.05), self-efficacy (P < 0.05), and strength of knee extension (P < 0.05) were significant in the self-monitoring group compared with those in the control group. No increase in bleeding frequency and pain scale was noted. The self-monitoring of home exercise for haemophilic patients is useful for the improvement of exercise adherence, self-efficacy and knee extension strength.

T2 mapping of muscle activity using ultrafast imaging

Measuring exercise-induced muscle activity is essential in sports medicine. Previous studies proposed measuring transverse relaxation time (T(2)) using muscle functional magnetic resonance imaging (mfMRI) to map muscle activity. However, mfMRI uses a spin-echo (SE) sequence that requires several minutes for acquisition. We evaluated the feasibility of T(2) mapping of muscle activity using ultrafast imaging, called fast-acquired mfMRI (fast-mfMRI), to reduce image acquisition time. The current method uses 2 pulse sequences, spin-echo echo-planar imaging (SE-EPI) and true fast imaging with steady precession (TrueFISP). SE-EPI images are used to calculate T(2), and TrueFISP images are used to obtain morphological information. The functional image is produced by subtracting the image of muscle activity obtained using T(2) at rest from that produced after exercise. Final fast-mfMRI images are produced by fusing the functional images with the morphologic images. Ten subjects repeated ankle plantar flexion 200 times. In the fused images, the areas of activated muscle in the fast-mfMRI and SE-EPI images were identical. The geometric location of the fast-mfMRI did not differ between the morphologic and functional images. Morphological and functional information from fast-mfMRI can be applied to the human trunk, which requires limited scan duration. The difference obtained by subtracting T(2) at rest from T(2) after exercise can be used as a functional image of muscle activity.

Intelligent Powered Wheelchair Assistance in Daily Use

In answer to Japan’s rapidly aging society, whose rising number of older people mandates that care requirements for care recipients be minimized, we developed an intelligent powered wheelchair featuring four assistance functions – approach through gesture recognition, assistance in standing, walking assistance, and operational assistance through posture recognition. Experiments demonstrated the usefulness of the four assistance functions.

[Visualizing muscle activation by fusing fast MR images]

The purpose of this study was to conduct fast-acquired muscle functional magnetic resonance imaging (fast-mfMRI). Fast-mfMRI is a method of fusing fast MR images in order to visualize muscle activity. Exercise selectively increases the signal intensities (SI) of active muscles in T2-weighted magnetic resonance (MR) images. A fast-mfMRI image is a fusion of two types of images: an anatomic image acquired by the TrueFISP method and a functional image acquired by the SE-EPI (spin-echo echo-planar-imaging) method. MR images of four healthy males were recorded at rest before and after plantar flexion. The Gain of the MR signal remained constant from before the flexion exercise (at rest) to after the exercise. The data on the area of muscle activity could be extracted by adapting a threshold value obtained by a functional image at rest to the functional image after the exercise. By uniting the data on the area of muscle activity with the anatomic images after the exercise, we constructed a fused image rich in anatomical information and effective in visualizing muscle activity. These fast-mfMRI images can be acquired in 14 seconds. Our results suggest that fast-mfMRI has the potential to measure muscle activity in the trunk, where conventional mfMRI has been ineffective.

Relationships of parenting strain and mental health with family needs in mothers of severely handicapped school-aged children suffering from cerebral palsy

OBJECTIVE

The study was designed to clarify relationships of family needs of mothers of school-aged children suffering from cerebral palsy with the parenting strain and mental health.

METHODS

The subjects were 249 mothers of cerebral palsy children from schools for the physically handicapped in Japan. The survey item consisted of sex and age of the children and age, family needs, parenting strain, and mental health of the mothers. Family needs of the mothers were determined according to "The Family Needs Survey". Parenting strain was assessed according to the "Parenting Strain Index for Parents with Disabled Children". Mental health was measured according to "General Health Questionaire-12". In the statistical analysis, an indirect model, with the parenting strain and family needs as the primary and secondary factor, respectively was postulated for mother's mental health, and fit of the model to the data was investigated.

RESULTS

The Comparative Fit Index (CFI) was 0.962, the Tucker-Lewis Index (TLI) was 0.977, and the Root Mean Square Error of Approximation (RMSEA) was 0.058; these indices were statistically within the tolerance range. The path coefficient of correlation of the parenting strain with the family needs was 0.656, and the path coefficient of the parenting strain with mental health was 0.406; both were statistically significant.

CONCLUSION

Relationships between family needs of mothers of cerebral palsy children from schools for the physically handicapped children and the mothers' parenting strain and mental health were indicated. The findings suggested that in order to develop and implement social intervention strategies for reducing mothers' parenting strain and providing solutions, it is imperative to extensively consider what family needs are and what solutions are required to resolve those needs.

Effect of occlusion status on the time required for initiation of recovery in response to external disturbances in the standing position

BACKGROUND

To examine whether occlusion status contributes to improvement of postural balance.

METHODS

Thirty healthy adolescents (15 males and 15 females; mean age, 20.3; standard deviation (SD) 1.6 years) with no equilibrium or stomatognathic function abnormalities were examined. Occlusion is a term meaning "jaw clenching." Occlusion status was evaluated by measuring masseter activity using the EMG system. Balancing ability was evaluated using the EquiTest system, which measures sway of the center of gravity produced by rapid movement of force plates as an external disturbance (three intensity levels). The time required for initiation of recovery after application of the disturbance was calculated by measuring displacement of the center of foot pressure. Data were compared according to occlusion status.

FINDINGS

Little difference in latency was observed following a small disturbances; however, the greater the disturbance the shorter the latency with occlusion, while without occlusion, latency increased with increasing disturbance. A statistically significant interaction (P<0.001) between occlusion and external disturbance was also found.

INTERPRETATION

This study suggested that occlusion contributes to maintenance of postural balance and improvement of stability when unexpected sway occurs in the standing position.