BACKGROUND: The coupling and coordination control of the multi-link rigid body of human body is the key to stable walking. It is reported that the use of cell phones greatly increases the chance of falling down stairs when walking; however, it lacks the analysis of the dynamic stability, motion coordination and joint mechanics of the lower limbs when walking down stairs with cell phone intervention. OBJECTIVE: To investigate the effects of cell phone on coupling control strategy of the multi-link rigid body in lower extremity during stair descent. METHODS: Twenty healthy university students were recruited and conducted the stair descent under no-interference (single task) and cell phone (phone task) randomly. Using the method of synchronous acquisition of 3D kinematics and dynamics, the kinetic and kinematic data were synchronously collected to acquire the parameters of stair descent under both conditions. RESULTS AND CONCLUSION: (1) The intervention of phone task significantly reduced the dynamic stability in anterior-posterior/media-lateral direction, the first knee extension moment peak, the first dorsiflexion moment peak, the second hip flexion moment peak in sagittal plane during stance phase, and significantly increased the mean and standard deviation of hip-knee/knee-ankle relative phase angles during swing phase. (2) It is concluded that when the gait of human body changes from time to time, the coupling control ability of multi-link rigid bodies decreased and the risk of falling increased. (3) The intervention of phone task reduces the supporting moment of lower limbs in the supporting phase, reduces the stability of adjacent joint coordination control in the swinging phase, reduces the dynamic stability in front, back and inside directions, and increases the risk of falling.

Objective To determine relationships between daily activities measured as modified version of Pulmonary Functional status and Dyspnea Questionaire (PFSDQ-M) and functional capacity and symptoms experienced in patients with chronic obstructive pulmonary disease (COPD). Methods Convenience sample of 94 COPD patients with stable condition were assessed by interview with PFSDQ-M Chinese version and modified Medical Research council dyspnea scale (MMRC) respectively. Pulmonary function test (PFT) and 6-minute walking test (6MWT) were undergone on the same day or within one week as interview. PFSDQ-M has three subscales,i.e.,change experienced by patient with activities (CA),dyspnea with activities (DA) and fatigue with activities (FA). Results Scores of CA,DA and FA correlated to 6-minute walking distancer= (-0.37)- (-0.42),FEV_1 r=(-0.27)-(-0.32),FEV_1/FVC r= (-0.27)- (-0.32),dyspnea rated by MMRC (r=0.55-0.60) and BODE index (r=0.35-0.40),respectively (all P<0.01). dyspnea explained 26% of the variance in changes of activities. Conclusions Physical activities moderately changed in patients with stable COPD;Dyspnea is the best predictor of limitation of daily activities.

BACKGROUND:Stability of the support surface and visual input are important factors affecting static balance,but most of the studies on the balance ability of elderly with mild cognitive impairment have focused on the stable hard support surface,and the control of static balance on the unstable support surface under different visual input conditions is not known. OBJECTIVE:To investigate the static balance ability of the elderly with mild cognitive impairment on soft and hard support surfaces under different visual input conditions. METHODS:Twenty-one elderly people with mild cognitive impairment and nineteen elderly people with normal cognition were selected for the study,and the Kistler three-dimensional dynamometer was used to conduct four tests:standing with two feet on hard support surface with eyes open,standing with two feet on soft support surface with eyes open,standing with two feet on hard support surface with eyes closed,standing with two feet on soft support surface with eyes closed,and standing with two feet on soft support surface with eyes closed,and the duration of each test was 30 seconds.The plantar center of pressure data were collected and compared between the two groups under different visual conditions on the soft and hard support surfaces. RESULTS AND CONCLUSION:(1)Under the condition of visual input,the total excursions(soft support surface:P=0.003),the total excursions-medial-lateral sides(soft support surface:P=0.001,hard support surface:P<0.001)and the 95%confidence ellipse area(soft support surface:P=0.001,hard support surface:P<0.001)of the center of pressure in the elderly with mild cognitive impairment on the soft and hard support surfaces were significantly higher than those of the elderly with normal cognition.(2)In the absence of visual input,the root mean square distance(P=0.014),the root mean square distance-medial-lateral sides(P=0.014),and the 95%confidence ellipse area(P=0.001)of center of pressure in the elderly with mild cognitive impairment on the soft support surfaces were significantly higher than those of the elderly with normal cognition,but there were no significant differences between the groups on the hard support surface(P>0.05).(3)These findings confirm that compared with the elderly with normal cognition who could make full use of visual sensory input to maintain body balance on the soft and hard support surfaces,mild cognitive impairment elderly presented a deficit in balance function.In particular,mild cognitive impairment elderly relied more on ankle proprioception to maintain balance when visual interference was present,suggesting that mild cognitive impairment elderly should focus on strengthening ankle proprioceptive training.

Objective:Through meta-analysis, the association of three common adipokines (leptin, adiponectin, and chemerin) with bone nutrition of senile osteoporosis (SOP) in China was systematically evaluated.Methods:CNKI, CBM, VIP, Wanfang, PubMed, Web of Science, Embase, Cochrane Library, and other databases were searched for articles published from the establishment of the database to July 30, 2022. After literature screening, data extraction, and quality evaluation of the included studies were independently conducted by two researchers, a meta-analysis was performed using RevMan5.4 and Stata17.0 softwares.Results:A total of 13 studies in the Chinese population were included, including 897 patients with SOP and 673 elderly with normal bone mineral density . The results of the meta-analysis showed that compared with the control group, the serum leptin levels were significantly lower ( MD -2.64, 95% CI -4.04 to -1.23, P < 0.001), chemerin levels were significantly higher ( MD 25.23, 95% CI 14.57 to 35.90, P < 0.001), and adiponectin levels were not significantly different ( MD -0.55, 95% CI -2.26 to 1.17, P > 0.05) in SOP patients. After subgroup analysis according to the measurement method, leptin levels remained lower in SOP patients than in the control group. Conclusions:Compared with the control group, leptin levels were lower and chemerin levels were higher in SOP patients. Therefore, dysregulation of adipokines may play an important role in the occurrence and development of SOP, and regulation of adipokine levels and functions may play a role in the treatment of SOP and the improvement of bone nutrition as a nutritional intervention.