Investigation of the quadriceps muscle function in healthy elderly / 中华老年医学杂志

ABSTRACT

Objective Backgrounds and Objectives Skeletal muscle dysfunction is an important systemic manifestation of several diseases such as chronic obstructive pulmonary disease and chronic heart failure.Quadriceps function assessment was used in majority of the studies for assessment of peripheral skeletal muscle function as it is readily accessible and is a primary locomotor muscle.Appropriate evaluation of the prevalence and severity of quadriceps dysfunction relies on the proper control data from the age-matched normal subject.So,the present study was aimed to measure the quadriceps function in healthy elderly,to investigate the multiple factors related to quadriceps functions,and to establish the normal ranges for quadriceps functional performance in healthy elderly.Methods Sixty healthy volunteers were recruited for the study.Quadriceps function was assessed by measurement of the following 3 items:maximum of twitch tension (TwQmax) induced by magnetic stimulation of femoral nerve,maximal volitional contraction (QMVC),and endurance time.The intensity and frequency of quadriceps exercises were quantified with physical activity (PA) scores by using a special PA questionnaire.Anthropometric measurements such as height,weight and mid-thigh muscle mass (MTMC) were measured in all of the subjects.Multiple regression models were developed by stepwise method to determine the independent factors respectively contributing to the quadriceps functional performance.Results Quadriceps functional tests results showed that the data of the three items fit normal distributions in both female and male subjects,and the gendcr-related difference was observed in quadriceps strength,with TwQmax and QMVC being significantly decreased in female than in male subjects.The mean values and normal ranges for TwQmax,QMVC,and endurance time were [13.86(10.53-17.65)] kg,[42.06(34.45-49.67)] kg,and [81.08(58.52-103.66)] second,respectively,in male subjects; and they were [7.41(6.02-9.52)] kg,and [29.40(24.66-33.82)] kg,and [83.44 (60.81-106.67)] second,respectively,in female subjects.Stepwise regression correlation analysis showed that QMVC was related with sex,PA scores and weight (R2=0.61,P＜0.01) ; endurance time was predicted by PA scores,MTMC,body weight and sex (R2 =0.58,P ＜0.01) ; and TwQmax was predicted by sex,height and PA scores (R2 =0.67,P＜0.01).Conclusions Our study results demonstrate that quadriceps functional performance fits normal distributions in healthy elderly,and that quadriceps function is related to multiple factors such as subjects' sex,muscles exercises,weight,height,muscle mass,and etc,with muscles exercises being the most significant one,except of gender.We conclude that muscles exercises take a very important role in muscles functional performance in healthy elderly.