Effects of heel height and high-heel experience on foot stability during quiet standing.

BACKGROUND: The use of high-heeled shoes (HHS) introduces instability into the wearer's balance system but how high-heel experience might influence standing balance is less examined in literature. RESEARCH QUESTION: (1) Does foot stability decrease in both the antero-posterior (AP) and medial-lateral (ML) directions with increasing heel height during quiet standing? (2) Does high-heel experience improve the wearer's foot stability during quiet standing in high-heeled conditions? METHODS: Twenty-four young females (12 regular and 12 non-regular HHS wearers) were recruited to perform quiet standing while wearing shoes with heel heights of 1 cm, 5 cm, 8 cm and 10 cm. The effects of heel height on the mean center of pressure (COP), their variability (standard deviations) and mean COP velocities in both the AP and ML directions were analysed by one-way repeated measures ANOVA and Bonferroni post-hoc test. The effects of high-heel experience were analysed through independent samples t-tests. RESULTS: The variability of the COP in both directions increased with heel height, although significance was found only in the ML direction. The COP velocities in both directions were highest for the 1 cm heel, decreased as the heel increased to 8 cm and increased again for the 10 cm heel. Experienced HHS wearers exhibited significantly smaller COP variances (AP) for the 8 cm and 10 cm heels, smaller COP velocities (AP) for all heels, and smaller COP variances (ML) and COP velocities (ML) for the 10 cm heel. SIGNIFICANCE: The use of HHS results in greater stability distortions in both AP and ML directions but high-heel experience improves balance control under high-heeled conditions. Our findings enhance the understanding of how high-heel experience might influence standing balance in different heel height, and highlights the importance of the ML components of the in-foot COP measures in the examination of standing balance in HHS.

Garment needs of pregnant women based on content analysis of in-depth interviews.

AIMS: This study aims to identify the needs, concerns and problems of pregnant women when using maternity support garments. BACKGROUND: Maternity support belt is regarded as helpful in reducing low back pain during pregnancy. However, several garment-related problems exist which might lead to poor adherence behaviour undermining the benefit of garment therapy. DESIGN: A qualitative exploratory study. METHODS. Semi-structured interviews were conducted with 10 pregnant Chinese women who experienced low back pain during pregnancy. All the interviews followed an interview guide and different maternity support garments were shown to the participants as a method of tangible objects to stimulate responses. Content analysis was used to analyse the data. RESULTS: The results showed that 60% of pregnant women discontinued using maternity support garments due to excessive heat, perceived ineffectiveness, itchiness, excessive pressure around the abdomen and inconvenience of adjustment. The content analysis generated five main themes of needs including effective function, safety, skin comfort, ease to put on and take off and aesthetics of maternity support garments. DISCUSSION: The findings of the five main themes of needs were largely consistent with previous studies examining medical garments for overall satisfaction and compliance. The results revealed that women's physiological and psychological changes during pregnancy influenced their clothing preferences on both functional and aesthetical values. CONCLUSIONS: Maternity support garments are convenient and easily-accessible therapy to manage LBP during pregnancy and are frequently recommended and worn by pregnant women. However, inappropriate choice of garment therapy not only led to ineffectiveness but also undesirable effects. The key findings of the five main themes of garment needs in pregnant women will facilitate healthcare professionals in providing evidence-based advice to assist patients in the selection of an appropriate and optimal maternity support garment. RELEVANCE TO CLINICAL PRACTICE: These recommendations in the clinical practice will assist patients in making well informed treatment decisions and ultimately improve the quality of care.

Effectiveness of maternity support belts in reducing low back pain during pregnancy: a review.

AIMS: This article aims to review the literature published to date on the types, current use, the biomechanical effects and adverse effects of maternity support belts for low back pain during pregnancy, to identify future research directions. BACKGROUND: Lumbar/pelvic support belts are frequently recommended for the prevention and treatment of low back pain during pregnancy. DESIGN: Systematic review. METHODS: MEDLINE, CINAHL, the Cochrane Library and patents databases were electronically searched. RESULTS: Maternity support belts belong to one of the four main types of maternity support garments, which are widely commercially-available. Current research showed limited evidence in support of the commercial maternity products regarding the effectiveness in the prevention and/or treatment of low back pain during pregnancy, other than that from the manufacturers. However, potential stabilisation effect of maternity support belt was demonstrated in some studies. Adverse effects reported include increased pain, fetal heart rate changes, skin irritation and discomfort. CONCLUSIONS: There is insufficient scientific evidence to conclude that wearing maternity support belts reduces pregnancy-related low back pain and/or pelvic girdle pain. Future research directions in the area of biomechanics and physiology are recommended. RELEVANCE TO CLINICAL PRACTICE: This review provides comprehensive understanding of the effectiveness of maternity support belts for the relief of low back pain during pregnancy which will facilitate healthcare professionals in providing evidence-based advice to their patients.

Evaluation of the performance of using mean absolute amplitude analysis of thoracic and abdominal signals for immediate indication of sleep apnoea events.

AIM: To evaluate the sensitivity of mean absolute amplitudes of the thoracic and the abdominal signals as a prompt indicator of the occurrence of sleep apnoea events. BACKGROUND: To provide symptomatic management of sleep apnoea, a reliable method of detecting sleep apnoea is essential to ensure that the intervention can be applied only when needed. It is also crucial to identify the threshold for the trigger of an intervention using a deployed sensor. DESIGN: Twenty-six subjects aged between 18-65 years who were diagnosed with obstructive or central sleep apnoea underwent an overnight sleep study. METHOD: Signals of nasal and oral airflow, thoracic and abdominal efforts and pulse oximetry level were recorded using a polysomnography device. RESULTS: With a 95% CI, the overall area under the receiver operating characteristic of the thoracic signal, the abdominal signal and the combination of the thoracic and the abdominal signals were 84.56, 87.48 and 90.91%, respectively. Using -20, -25 and -30% as a cut-off point, the sensitivity values of thoracic signal, abdominal signal and combination of the thoracic and the abdominal signals ranged from 70.29-86.25% and the specificity values ranged from 74.82 to 90.09%. CONCLUSIONS: Using mean absolute amplitude analysis, the results of this study showed that combination of the thoracic and the abdominal signals achieved the best overall and individual performances compared with thoracic signal and abdominal signal. Overall, thoracic signal, abdominal signal and combination of the thoracic and the abdominal signals have a good performance with an receiver operating characteristic value higher than 80%. The thoracic and the abdominal signals were good parameters for the identification of the occurrence of sleep apnoea, being as quick as the nasal airflow signal. RELEVANCE TO CLINICAL PRACTICE: These results suggested that sleep apnoea events could be identified through constant monitoring of the patient's thoracic and abdominal signals. Knowledge of these signals could help nurses to manage sleep apnoea in patients.

Using pulse oximetry level to indicate the occurrence of sleep apnoea events.

The aim of this research study was to identify an alternative to nasal airflow as a prompt and unobtrusive indicator of sleep apnoea events. This study attempted to select pulse oximetry (SpO2) level as an alternative parameter to indicate the occurrence of sleep apnoea. Ten subjects diagnosed with sleep apnoea underwent an overnight polysomnography (PSG) study. Signals of nasal flow and SpO2 level were recorded. Time differences were compared between the "onset of nasal airflow cessation" (ONAC) and the "onset of three percent oxygen desaturation from the baseline" (OOD) during sleep apnoea events. The results of this study showed that measuring SpO2 level was more comfortable for patients, but that there was around a twenty second delay after the onset of the cessation of nasal airflow. It was concluded that the measurement of SpO2 level was useful for screening suspected sleep apnoea patients, but it might not be able to provide "online detection" of the occurrence of sleep apnoea events.