Body mass-based exercise in daily life improves muscle function in lower limbs and cognitive functions in elderly persons.

本研究旨在探讨日常生活中基于体质量的运动是否能改善老年人膝关节伸肌的力量能力和认知功能（通过简易精神状态检查（MMSE）评估）。首先，我们试图阐明基于体质量的下蹲运动中股四头肌（QF）的力量产生能力与其表面肌电活动之间的关系。研究对象为3男48女，年龄19 - 90岁，包括18名使用长期护理保险制度的体弱老人。在基于身体质量的下蹲运动中，QF的% EMGmax与相对于身体质量的最大膝关节伸展扭矩（KET/BM）呈非线性相关。线性分段连续回归分析显示，两个变量之间的关系存在1.9 Nm/kg的断点。在KET/BM小于1.9 Nm/kg的个体中，随着KET/BM的降低，QF % EMGmax迅速增加。这些结果表明，QF的活动水平，在身体质量为基础的深蹲运动， ...更多信息 它受其部队生成能力的影响。对于KET/BM小于1.9 Nm/kg的个体，考虑基于体质量的下蹲运动。其次，我们研究了中年和老年女性通过基于体质量的家庭锻炼计划改善肌肉力量的程度是否取决于干预前肌肉的力量产生能力。75名女性（53 - 76岁）自愿参加了为期3个月的循环训练计划，该计划包括5次练习（16次重复/练习，2或3次循环/天），仅使用体重作为阻力。受试者每周在自己家中进行6天的训练计划，每周在当地健身房进行一次。干预后，膝关节最大随意伸展（KET）和跖屈（PFT）时的等长力矩显著增加，其相对变化与干预前的绝对值呈负相关。干预前KET/BM和PFT/BM值分别大于2.8 Nm/kg和1.7 Nm/kg的受试者中，大多数在干预后没有出现力量的增加，这表明基于体质量的家庭锻炼对改善中老年女性下肢力量是有效的，而且改善的幅度受干预前力量产生能力的影响。最后，我们研究了膝关节伸肌的力量能力是否与整体认知功能相关，通过简易精神状态检查（MMSE）评估，在非残疾老年男性。在39名年龄在61 - 79岁的非残疾男性中测定了最大自愿膝关节伸展、跖屈和肘关节屈曲时的等距扭矩和MMSE评分，并用于横断面分析，检查测量变量之间的关联。此外，27名受试者参加了一项训练计划，包括每周6天的基于身体质量的锻炼（坐在椅子上和从椅子上站起来，髋关节伸展和弯曲，小腿抬高，侧腿抬高，躯干弯曲和伸展），持续3个月。干预后测定等长扭矩和MMSE评分。在干预前的数据中，只有膝关节伸展力矩（KET）和KET/BM与MMSE评分显著相关：KET的r = 0.579（P <0.0001）和KET/BM的r = 0.520（P <0.001）。干预后KET、KET/BM较干预前明显升高，MMSE评分无明显变化。但MMSE评分的绝对变化与KET评分的绝对变化显著相关（r = 0.381，P <0.05）与KET/BM（r = 0.422，P <0.05），提示非残疾老年男性膝关节伸肌群力量能力与整体认知功能相关，并提供了一个新的观点，一般的概念，锻炼加强膝伸肌应包括在阻力训练计划的老年人。少

The present study examined if the body mass based exercise in daily life improves strength capability of knee extensor muscles and cognitive functions assessed by by Mini-Mental State Examination (MMSE), in elderly persons.First, we attempted to clarify how the force-generating capability of quadriceps femoris (QF) is associated to its surface EMG activity during a body mass‐based squat movement. Subjects were 3 men and 48 women age 19-90 yr, including 18 frail elderly persons who used the long-term care insurance system. During body mass‐based squat movement, %EMGmax of QF was nonlinearly related to maximal knee extension torque relative to body mass (KET/BM). Linear piecewise continuous regression analysis showed that there was a breakpoint of 1.9 Nm/kg in the relationship between the two variables. In individuals with KET/BM less than 1.9 Nm/kg, QF %EMGmax rapidly increased as KET/BM decreased. These results indicate that the activity level of QF during a body mass‐based squat movem … More ent is influenced by its force generation capability. For individuals with a KET/BM less than 1.9 Nm/kg, body mass‐based squat movement is considered.Second, we examined whether the degree to which muscle strength is improved by a body mass-based home exercise program in middle-aged and older women depends on the force generating capabilities of the muscles prior to the intervention. 75 women (53-76 years) voluntarily participated in a circuit training program consisting of 5 exercises (16 repetitions/exercise, 2 or 3 circuits/day) using only body mass as resistance for 3 months. The subjects performed the training program 6 days a week in their own home and once a week in a local gym. After intervention, isometric torques during maximal voluntary knee extension (KET) and plantar flexion (PFT) increased significantly after intervention, and their relative changes were negatively correlated to the absolute values before intervention. Most of the subjects whose KET/BM and PFT/BM values before intervention were greater than 2.8 Nm/kg and 1.7 Nm/kg, respectively, did not show increases in strength after intervention.These results suggests that body mass-based exercise at home is effective in improving lower limb strength in middle-aged and older women, and the magnitude of the improvement is influenced by the force-generating capability before intervention. Lastly, we examined whether the strength capability of knee extensor muscles is associated with global cognitive function, assessed by Mini-MentalState Examination (MMSE), in non-disabled elderly men. Isometric torques during maximal voluntary knee extension, plantar flexion, and elbow flexion and MMSE scores were determined in 39 non-disabled men aged 61-79 years and used for the cross-sectional analysis examining the associations among the measured variables. Moreover, 27 of the subjects participated in a training program consisted of body mass-based exercises (sitting down onto and standing up from a chair, hip joint extension and flexion, calf raises, side leg raises, and trunk flexion and extension) 6 days a week for 3 months. Isometric torques and MMSE scores were determined after the intervention. Among the data before intervention, only knee extension torque (KET) and KET relative to body mass (KET/BM) significantly correlated to the MMSE scores: r = 0.579 (P < 0.0001) for KET and r = 0.520 (P < 0.001) for KET/BM. After the intervention, KET and KET/BM increased significantly, but MMSE score did not. However, the absolute change in MMSE scores was significantly associated with that in KET (r = 0.381, P < 0.05) and KET/BM (r = 0.422, P < 0.05).These findings indicate that the strength capability of knee extensors is associated with global cognitive function in non-disabled elderly men, and provide a new perspective to a general concept that exercises strengthening knee extensor muscles should be included in resistance training programs for elderly individuals. Less