Objective:To observe the aging-related trends and age-sensitive changes in postural control reaction time(RT)and movement time(MT)during the adaptive balance after instability. Method:A total of 97 healthy adult subjects aged 20-79 were tested for posture control time using the DE-A somatosensory balance detection system.The test included postural adjustment RT and MT during the adaptive balance(e.g.forward,backward,left and right)tilts of the support surface under static and dynamic balance states.The subjects were sequentially divided into six age groups based on 10-year age intervals,with 16 in Group 1(20-29 years),10 in Group 2(30-39 years),17 in Group 3(40-49 years),18 in Group 4(50-59 years),31 in Group 5(60-69 years)and 5 in Group 6(70-79 years).The age-related trends and age-sensitive changes in postural control RT and MT were observed and analyzed. Result:The postural control RT and MT increased with age.In static balance,all RT and MT indicators were longer in group 6 than in groups 1 to 5,with significant differences compared with groups 1 to 4(P＜0.05)but no significant differences compared to group 5(P＞0.05).All RT and MT indicators were longer in group 5 than in groups 1 to 4,and there were significant differences(P＜0.05).All RT and MT indicators were lon-ger in group 4 than in groups 1 to 3,with a significant difference compared with group 1 in RT when the support surface was tilted to the right(P＜0.05),but no significant differences between groups for the remain-ing indicators(P＞0.05).All RT and MT indicators were longer in group 3 than in groups 1 to 2,with a sig-nificant difference compared with group 1 in MT when the support surface was tilted to the left(P＜0.05),but no significant differences between groups for the remaining indicators(P＞0.05).There was no significant difference(P＞0.05)between group 2 in all RT and in MT compared with group 1.In dynamic balance,all RT and MT indicators were longer in group 6 than in groups 1 to 5,with significant differences compared with groups 1 to 4(P＜0.05)but no significant differences compared with group 5(P＞0.05).All RT and MT indicators were longer in group 5 than in groups 1 to 4,but there were no significant differences(P＞0.05).All RT indicators were longer in group 4 than in groups 1 to 3,with no significant differences compared with group 1 in RT when the support surface was tilted to the left(P＞0.05),while there were significant dif-ferences between groups for the remaining RT indicators(P＜0.05).All MT indicators were longer in group 4 than in groups 1 to 3,with significant differences compared with group 2 in MT when the support surface was tilted to the back and left(P＜0.05),while there were no significant differences between groups for the remaining RT indicators(P＞0.05).All RT indicators were longer in group 3 than in groups 1 to 2,with no significant differences compared with group 1(P＞0.05).All MT indicators were longer in group 3 than in groups 1 to 2,with significant differences compared with group 1(P＜0.05).There was no significant differ-ence between group 2 in all RT and in MT compared with group 1(P＞0.05). Conclusion:The postural control RT and MT during the adaptive balance after instability gradually increase with aging.The deterioration of postural control response time and motion time in static balance may start to become evident around the age of 60,while in dynamic balance,these deteriorations may begin to appear around the ages of 50 and 40,respectively.

Objective:To study the protective effect of alendronate combined with Lactobacillus rhamnosus on bone loss in ovariectomized mice.Methods:Fifty female C57BL/6 mice were divided into 5 equal groups ( n=10). Ovariotomy was performed in groups A, B, C and D while a sham operation was performed in group E. Group A was subjected to combined administration of alendronate and Lactobacillus rhamnosus, group B to administration of alendronate, group C to administration of Lactobacillus rhamnosus, and groups D and E to administration of physiological saline only. At 3 months after operation, all the mice were sacrificed to harvest their femurs. Micro CT scanning was performed to detect the bone mineral density (BMD), trabecular relative volume, bone surface area/bone volume, and trabecular thickness and number of trabecular bone. Three-point bending test was used to detect the maximum load, stiffness, ultimate load, Young＇s modulus, and fracture energy. Osteocalcin and alkaline phosphatase levels were measured using blood samples from the mice eyeballs. The 2 groups were compared in terms of all the above indexes. Results:The BMD [(669.87±67.87) mg/cm 3], maximum load [(14.35±0.75) N] and fracture energy [(1,497.43±38.29) J/m 2] in group A were significantly higher than those in group B [(520.07±9.01) mg/cm 3, (11.94±0.82) N and(1,277.61±35.12) J/m 2] and group C [(388.15±25.61) mg/cm 3, (11.10±0.93) N and (1,115.27±63.24) J/m 2] (all P<0.05). The osteocalcin level in group A [(22.25±1.78) ng/mL] was significantly higher than that in group B [(19.08±1.45) ng/mL] and group D [(19.33±1.66) ng/mL] (both P<0.05). The alkaline phosphatase level in group A [(83.21±9.69) ng/mL] was significantly lower than that in group C [(113.16±14.44) ng/mL] and group D [(137.96±14.01) g/mL] (both P<0.05). Conclusion:Alendronate combined with Lactobacillus rhamnosus may play a synergistic role in prevention of bone loss in ovariectomized mice, because combined administration of the two is more effective than administration of either of the two.

ObjectiveTo investigate the individual factors of postural adjustment reaction time and movement time during adaptive equilibrium. MethodsFrom March to December, 2021, 126 healthy adults aged 18 to 80 years were recruited at the First Medical Center of the General Hospital of the Chinese PLA. The DE-A somatosensory balance detection system was used to detect their postural adjustment reaction time (RT) and movement time (MT) as the platform tilting in multiple directions during standing (static) or walking (dynamic). The ages, genders, body mass index (BMI) and physical activity level of them were investigated. ResultsThe age was the only factor independently associated with dynamic RT and MT in all the directions (β > 0.632, P < 0.05). For static MT, as the platform tilting forward, physical activity level (β = -0.143, P < 0.05), BMI (β = 0.154, P < 0.05) and age (β = 0.663, P < 0.05) were the independently associated factors; as the platform tilting leftward, gender (β = -0.173, P < 0.05) and age (β = 0.647, P < 0.05) were the independently associated factors; and age was the only independently associated factor for other directions (β > 0.571, P < 0.05). For the static RT, age was the only independently associated factor for all the directions (β > 0.615, P < 0.05). ConclusionAge is the most important independently factor related to postural adjustment during adaptive equilibrium, and aging may delay the postural adjustment after instability.