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

本研究探讨了日常生活中基于身体质量的锻炼是否能改善老年人膝关节伸肌的力量能力和简易智力状态检查(MMSE)评估的认知功能。首先，我们试图阐明在基于身体质量的下蹲运动中，股四头肌(QF)的力量生成能力与其表面肌电活动的关系。研究对象为3名男性和48名女性，年龄19-90岁，包括18名使用长期护理保险制度的体弱老年人。在基于身体质量的下蹲运动中，QF的%EMGmax与最大伸膝扭矩(KET/BM)呈非线性相关。线性分段连续回归分析表明，两个变量之间的关系存在着1.9 Nm/kg的转折点。在KET/BM<1.9 Nm/kg的个体中，QF%EMGmax随着KET/BM的降低而迅速增加。这些结果表明，在基于身体质量的下蹲运动中，QF的活动水平在…更多的ENT受到其力量产生能力的影响。对于KET/BM小于1.9 Nm/kg的个体，考虑基于身体质量的下蹲运动。第二，我们研究了中老年女性通过基于身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个练习(16次重复/练习，2或3个循环/天)，仅使用身体质量作为阻力。受试者每周在自己家里进行6天的训练，每周在当地的健身房进行一次训练。干预后膝关节最大伸膝和足底屈曲时的等长扭矩在干预后显著增加，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分别大于2.8Nm/kg和1.7Nm/kg的受试者大多数在干预后没有表现出力量的增加，这一结果表明，家庭中基于身体质量的锻炼对提高中老年女性的下肢力量是有效的，其提高的幅度受干预前的力量产生能力的影响。最后，我们检查了非残疾老年男性的膝关节伸肌力量能力是否与通过Mini-MentalState检查(MMSE)评估的整体认知功能有关。对39名61-79岁的非残障男性进行了膝关节最大伸展、足底屈曲和屈肘时的等长扭矩和MMSE评分，并进行横断面分析，以检验测量变量之间的关系。此外，其中27名受试者参加了为期3个月的每周6天的训练计划，包括基于身体质量的练习(坐在椅子上和从椅子上站起来，髋关节伸展和屈曲，小腿抬高，侧腿抬高和躯干屈伸)。干预后测定等长扭矩和MMSE评分。在干预前的数据中，只有膝关节伸展扭矩(KET)和KET/BM与MMSE评分显著相关：KET r=0.579(P&lt；0.0001)，KET/BM r=0.520(P&lt；0.001)。干预后KET、KET/BM显著升高，而MMSE评分无明显变化。然而，简明精神状态量表得分的绝对变化与KET(r=0.381，P<0.05)和KET/BM(r=0.422，P<0.05)的绝对变化显著相关。这些发现表明，在非残疾老年男性中，膝关节伸肌的力量能力与整体认知功能有关，并为老年个人阻力训练计划中应包括加强膝关节伸肌的普遍概念提供了新的视角。较少

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