Characteristics of calcaneal inclination of children in the upright standing position / 体力科学

Calcaneal inclination in children may influence their standing posture. However, the calcaneal inclination of modern children is unclear. This study aimed to clarify the characteristics of calcaneal inclination and its effects on spinal alignment and the center of pressure (COP) position in children. The study included 402 elementary school children (208 boys, 194 girls). The variables measured included calcaneal inclination, lower leg lateral inclination angle, spinal alignment, and COP position. The mean calcaneal inclination was 4.40 ± 3.5°, indicating mild eversion. Calcaneal inclination was classified into calcaneal eversion (+), calcaneal introversion (-), and a mid-heel position. Overall, 3.7% (15/402) of the subjects had bilateral calcaneal introversion (-), 18.2% (73/402) had unilateral calcaneal introversion (-), and 21.9% (88/402) had calcaneal introversion (-). An examination of the relationship between calcaneal inclination and each measured variable showed a significance level of <5% between calcaneal inclination and age, height, and body weight, but the correlation coefficients were <0.2 each, indicating little correlation. However, a significant correlation was found between right and left calcaneal inclination and the right and left lower leg lateral inclination angles. Overall, 21.9% (88/402) of the elementary school children had calcaneal inclination in a standing posture. These results suggest that calcaneal inclination may not affect spinal alignment and COP position.

Effect of using a spine mat on sagittal spinal alignment in children / 体力科学

Recently, poor posture (hyperkyphosis) has become a problem among children. This study investigated the effectiveness of an intervention (a spine mat) by measuring spinal alignment before and after the intervention in elementary school students. The study included 83 elementary school students. For the intervention, each participant was placed in a supine position on a bed and a spine mat was inserted ensuring that it adhered to the thoracic spine. The primary outcome variables included the thoracic kyphosis angle (TKA), upper thoracic angle, lower thoracic angle, lumbar lordosis angle (LLA), and sacral anteversion angle (SAA) measured in the standing and sitting positions using Spinal Mouse® before and after the intervention. Based on this evaluation, we assigned the participants to two groups: hyperkyphosis (n=25) and non-hyperkyphosis (n=58). Significant differences were observed between the pre-test and post-test TKA in the hyperkyphosis group in the standing position (pre-test: 45.3±4.5° and post-test: 40.8±9.0°, P<0.05). In the non-hyperkyphosis group, significant differences were observed between the pre-test and post-test LLA and SAA in the standing position. However, no significant difference was observed between the pre-test and post-test spinal alignment in the sitting position in both groups. The results of this study indicated that using a spine mat in elementary school children resulted in decreased TKA in the standing position only in the hyperkyphosis group, which exhibited a TKA of 40° or more after the intervention.

Effect of pursed lip breathing on respiratory function and respiratory muscle strength while using a spine mat / 体力科学

It has been reported that using of the spine mat increases chest expansion, inspiratory capacity (IC) and maximum inspiratory mouth pressure (PImax). However, no changes were observed in other respiratory functions and the respiratory muscle strength. The purpose of this study was to clarify the effects of pursed-lip breathing lying on the spine mat to the respiratory function and respiratory muscle strength. Forty-two adult male participants were assigned to two groups; an intervention group (IG group) of 21 participants who performed pursed-lip breathing on top of a spine mat and a control group (CG group) of 21 participants who performed pursed-lip breathing only. The intervention period was 5 days, and the respiratory features evaluated were chest expansion, respiratory function, respiratory muscle strength, and spinal alignment. A significant increase between the Pretest and the Posttest in chest expansion at the circumference of the axilla level, of the xiphoid process level and of the 10th rib level was observed only in IG group. For the respiratory function and the respiratory muscle strength, intervention group showed significant increases in percentage of vital capacity (%VC), tidal volume (TV), PImax, and maximum expiratory mouth pressure (PEmax). In the control group, only the TV indicated a significant increase. Regarding changes before and after the intervention, the intervention group showed significantly higher PImax and PEmax than the control group. No significant difference in spinal alignment was observed between the two groups. These results showed that pursed-lip breathing lying on the spine mat would increase the PImax, PEmax and the chest expansion.