The association of pain,race and slow gait speed in older adults

Gait speed is an important indicator of mobility and quality of life in older adults. Pain is related to gait speed; however, it is unknown if this relationship varies by race in a population based national sample. The aim of this study was to examine if the association between slow gait speed and pain differed between 7,025 older African Americans and non Hispanic Whites in the National Health and Aging Trends Study. Those with pain in the last month had higher odds of slow gait speed (odds ratio?=?1.38, 95% confidence interval?=?1.10 - 1.73) than those without pain. The relationship between pain and slow gait speed did not vary by race (interaction p?=?0.6). This is important because it points to the underlying racial disparities in pain and gait speed being factors such as disparate opportunities and living conditions, and healthcare rather than attributes intrinsic to race.     

Relationship between gait speed and strength parameters in multiple sclerosis]

INTRODUCTION: Recent studies have focused on correlation between strength and gait parameters in hemiplegia, suggesting the interest for strength training in patients with central nervous system lesions. The aim of this study was to evaluate this correlation in multiple sclerosis (MS) patients with special regard to the different clinical forms including proprioceptive loss or cerebellar ataxia. PATIENTS AND METHOD: Gait speed and muscular function were performed in 27 patients with moderate affected gait (EDDS < 6). Gait speed was evaluated with Locometre and peak-torques of quadriceps and hamstrings were evaluated with isokinetic dynamometer. Patients were separated in three groups related to their deficiency: spastic group (8 patients), spastic with proprioceptive loss (12 patients) and spastic with cerebellar ataxia (7 patients). Gait parameters were evaluated in 10 healthy subjects as control group. RESULTS: Gait speeds (spontaneous and maximal) and peak torques of quadriceps and hamstring were similar in the three groups. In the whole patients group, gait speed was reduced and related to hamstring peak torque (r = 0.56 at spontaneous speed and 0.51 at high speed) but not with quadriceps peak torque. Patients with proprioceptive loss exhibited not only a higher correlation between gait speed and hamstring torque (r = 0.76 and 0.65 respectively) than other patients but also with quadriceps torque (r = 0.66 and 0.59 respectively) when patients in other groups did not. CONCLUSION: As it was previously pointed out in hemiplegic patients, MS patients exhibit some correlation between gait speed and muscle strength, mainly with hamstrings. These correlations can change in special sensory conditions suggesting that patients with sensory loss use different muscular strategies to maintain gait speed. Strength training may therefore be discussed in MS including specific modalities as a function of clinical parameters.     

高血压患者体质量指数与生存质量的关联性

目的:探讨高血压患者体质量指数(BMI)与生存质量(HRQOL)的关联性。方法:1463例高血压患者源于中国9省市(江苏、安徽、甘肃、青海、福建、北京、吉林、江西、河南)横断面健康状况调查数据库。生存质量使用中文版简明健康调查量表进行调查,血压由经过统一培训的医生现场测量。应用非参数秩和检验比较不同BMI分类的高血压患者生存质量的差异;应用Logistic回归模型,排除性别、年龄、婚姻状况、文化程度、运动习惯、血压水平、合并疾病因素影响后,分析不同体质量指数对生存质量的独立影响。结果:不同体质量指数的高血压患者,在生存质量的生理领域(PCS)、心理领域(MCS)以及PF、RP、GH、VT、SF、RE、MH 7个维度的得分差异具有显著性意义。无论在PCS领域还是MCS领域,均是超重组得分最高(PCS=72.56±19.34,MCS=75.78±18.75),体质量过低组得分最低(PCS=56.56±22.47,MCS=61.13±21.81)。不同性别、年龄、婚姻状况、文化程度、运动习惯、血压水平及有无合并疾病情况下,不同BMI分类的高血压患者生存质量不同。排除混杂因素影响后的Logistic回归结果显示,体质量过低的高血压患者在PCS领域(OR=3.08,95%CI:1.21—7.82)、MCS领域(OR=2.19,95%CI:1.04—4.61)以及PF、RP、VT、SF、RE维度生存质量受损的危险度是体质量正常组的2.14—3.44倍;肥胖的高血压患者在PF维度(OR=1.48,95%CI:1.06—2.06)生存质量受损的危险度是体质量正常组的1.48倍;而超重的高血压患者在GH维度(OR=0.75,95%CI:0.58—0.96)生存质量受损的危险度是体质量正常组的0.75倍。结论:体质量过低减损高血压患者生理、心理领域及多个维度的生存质量,肥胖减损高血压患者生理机能维度的生存质量,超重对高血压患者一般健康状况维度的生存质量有保护作用。     

Relationship between gait regularity and harmony,and gait speed at discharge in inpatients with subacute stroke

[Purpose] Accelerometry indices are a promising and simple method to quantify gait stability. However, the long-term relationship between gait stability and walking ability in patients with stroke has not been fully investigated. The purpose of this study was to longitudinally examine the relationship between gait regularity and harmony at admission and gait speed at discharge in inpatients with subacute mild stroke. [Participants and Methods] Sixteen patients with subacute stroke (median age, 69.5 years [1st–3rd interquartile range, 58.0–73.8 years]; 13 males) were enrolled in the study. A Spearman’s rank correlation coefficient was calculated for step regularity, stride regularity, the harmonic ratio at admission, and the walking speed at discharge. We also calculated the partial rank order correlation, controlling for balance ability. [Results] The vertical step regularity, harmonic ratio, and anterior-posterior harmonic ratio were all positively correlated with the walking speed at discharge. Positive correlations with vertical step regularity and harmonic ratio were found in partial rank order correlations when controlled for balance ability. [Conclusion] Vertical step regularity and gait harmony had predictive validity for discharge gait speed in patients with subacute stroke.     

Correlation of knee extensor muscle torque and spasticity with gait speed in patients with stroke

The purpose of this investigation was to determine in 17 stroke patients the correlation between two independent variables (knee extensor muscle torque [KET] and spasticity on the paretic side) and one dependent variable (gait speed). The patients had a mean age of 59 years; time since onset of first stroke was 51 days. Each variable was measured twice on each of two consecutive days. Both KET and spasticity were measured on a Cybex II dynamometer. Peak torque was measured during five-second maximal voluntary isometric knee extension efforts. Spasticity was defined by the relative angle of reversal (RAR) of the Cybex electrogoniometer curve obtained during pendulum tests. Gait speed was measured as patients walked 8.0 meters at their most comfortable speed while using their usual devices. The average of each day's KETs, RARs, and gait speeds was used in the calculation of Pearson product moment correlations. The correlations between KET and gait speed were significant (p less than .05) and were .574 (day 1) and .571 (day 2). The correlations between the RAR and gait speed were not significant (-.204 day 1 and -.262 day 2). All measurements had intraday and/or interday reliability coefficients (ICC 3,1) exceeding .930. The results of this study confirm that gait performance is correlated with measures of KET but not spasticity in stroke patients. Thus, at the knee, extensor muscle torque, unlike spasticity, appears to be justified as a practical and objective clinical measure.     

Changes in muscle group work associated with changes in gait speed of persons with stroke

BACKGROUND: Knowledge of associations between changes in muscle work with changes in gait speed could assist gait training in persons with stroke. The purpose of the study was to determine changes in the work of major muscle groups during gait that were associated with increases in walking speed of persons with stroke following training. METHODS: The gait of 28 subjects (14 males, 14 females) with mean age of 64.2 (SD 11.7) years, at 4.8 (SD 6.9) years post stroke was studied using two-dimensional motion analysis before and after a strength training program. Outcome variables were changes in gait speed and changes in work associated with the hip flexors and extensors, knee flexors and extensors and ankle plantar flexors bilaterally. A stepwise linear regression analysis determined best positive work predictors of changes in gait speed. FINDINGS: Hip extension work in early stance and ankle plantarflexion work in late stance of the affected side accounted for 74.9% of the variance in change of gait speed; a second model showed that hip extension work in early stance of the affected and less-affected sides accounted for 74.3%, a similar amount of variance. INTERPRETATION: This work is the first to explore the changes in muscle work during gait that are associated with speed increases in persons with stroke. Augmenting hip extensor work in early stance on both sides, as well as ankle plantarflexion thrust on the affected side may be particularly beneficial in increasing the speed of walking of persons with stroke.     

Relationship between gait speed and trunk muscles in frail elderly individuals

[Purpose] The external and internal abdominal muscles may be related to gait speed; however, this has not yet been elucidated. In this study, we aimed to clarify the relationship between gait speed and trunk muscle thickness in elderly individuals. [Participants and Methods] The participants were 12 elderly individuals (4 males and 8 females, mean age 83.4 years old, SD ± 0.5) that attend a day service center. We measured the 5 m free gait speed, the 5 m fastest gait speed, and the thickness of five trunk muscles (the rectus abdominis [divided into three parts: upper, central, and lower], external oblique, internal oblique, transverse abdominis, and iliopsoas muscles). [Results] There were positive correlations between the free gait speed and the thickness of the lower rectus abdominis, internal oblique, and transverse abdominis muscles. There were also positive correlations between the fastest gait speed and the thickness of the lower rectus abdominis, internal oblique, and transverse abdominis muscles. [Conclusion] Incorporating muscle strength training of the lower rectus abdominis, internal oblique, and transverse abdominis muscles into existing lower limb muscle training protocols is important to effectively maintain the gait speed of elderly individuals.Key words: Gait speed, Trunk muscles, Frail elderly individuals     

Relationship between ankle frontal muscle powers and three-d gait patterns

OBJECTIVE: This study was undertaken to demonstrate that the ankle frontal muscle power absorption and generation at push-off are related to the foot's initial position at heel-strike with respect to the body center of mass. DESIGN: Nineteen able-bodied male subjects participated in this study and were divided into two groups according to ankle frontal plane power generation or absorption at push-off. RESULTS: At heel-strike, the group that absorbed had a center of pressure that was located on average 25% more anteriorly and 36% more laterally to the body center of mass. Moreover, at push-off, the center of pressure was closer (26%) to the center of mass than in the generating group. The absorbing group compensated by increasing their sagittal plane hip energy by 30% to pull the lower limb forward and their knee power absorption by 47% to slow down the leg before the subsequent heel-strike. CONCLUSIONS: The foot's initial position at heel-strike explains in part the ankle frontal power generation or absorption at push-off. Increasing hip and knee sagittal joint powers and mechanical energies were the main contributors in compensating and providing a broader base of support and frontal plane ankle power absorption.     

肌力训练对偏瘫步态的影响及下肢功能评定与步态分析间的相关性

目的　本文探讨了偏瘫患者在恢复期行患肢膝关节屈伸肌群肌力训练的效果 ,以及下肢功能评定与步态分析之间的相关性。方法　 5 0例脑卒中患者随机分为观察组 ( 30例 )和对照组 ( 2 0例 ) ,二组患者康复训练相同 ,观察组患者在恢复期增加患肢股四头肌、绳肌肌力训练。治疗前后分别采用Fugl Meyer法、Barthel指数法及足印法对二组患者下肢功能及步态进行分析。结果　观察组患者步态较对照组明显改善 (P<0 .0 1)、运动功能与活动能力显著提高 (P <0 .0 1)。步态的对称性与下肢运动功能、平衡功能显著相关 (r =-0 .79,-0 .71、P <0 .0 1) ,与活动能力无关 (r =-0 .2 1,P >0 .0 5 ) ;步速与下肢运动功能、平衡功能、活动能力均显著相关 (r =0 .80、0 .78、0 .76 ,P <0 .0 1)。结论　偏瘫患者在恢复期行患肢膝屈伸肌群肌力训练有助于运动功能提高、步态改善 ;通过足印法步态分析可初步了解下肢步行能力。     

Association between height-corrected appendicular and regional skeletal muscle mass and insulin resistance in patients with type 2 diabetes

[Purpose] The effect of height-corrected skeletal muscle masses on insulin resistance has not been fully investigated in patients with type 2 diabetes. In this study, we aimed to investigate the association between height-corrected appendicular and regional skeletal muscle masses and insulin resistance in patients with type 2 diabetes. [Participants and Methods] We included 136 male and 100 female patients with type 2 diabetes (average age, male 55.7 ± 12.3 years old, female 60.7 ± 11.3 years old, and average height, male 1.67 ± 0.06 m, female 1.54 ± 0.06 m) in this study. Bioelectrical impedance analysis was used to evaluate skeletal muscle mass. We calculated the appendicular skeletal muscle mass index by dividing the appendicular skeletal muscle mass by the square of the patient’s height. The upper limb muscle mass, lower limb muscle mass, and trunk muscle mass figures were also divided by the square of the patient’s height. We used the homeostasis model assessment of insulin resistance as a marker of insulin resistance. [Results] In multiple regression analysis, the homeostasis model assessment of insulin resistance was inversely associated with appendicular skeletal muscle mass index and lower limb muscle mass/height² in male patients with type 2 diabetes when adjusted for age and body mass index. Similarly, the homeostasis model assessment of insulin resistance was inversely associated with appendicular skeletal muscle mass index and lower limb muscle mass/height² in non-obese female patients with type 2 diabetes. [Conclusion] We have confirmed that there is an association between appendicular skeletal muscle mass index and lower limb muscle mass/height² with insulin resistance in male and female patients with type 2 diabetes, except in females with obesity.     

Relationships between muscle mass,intramuscular adipose and fibrous tissues of the quadriceps,and gait independence in chronic stroke survivors: a cross-sectional study

Objective

To examine the relationships between muscle mass, intramuscular adipose and fibrous tissues of the quadriceps, and gait independence in chronic stroke survivors.

The association between external-ground-reaction force and knee-joint kinetics during partial- and full-weight-bearing gait

BackgroundProgressive weight-bearing is recommended following autologous chondrocyte implantation. This weight-bearing program assumes that increasing external loads experienced at the foot during gait are closely related to external-knee-joint moments. We investigated this relationship, and examined other variables that may contribute to knee-joint kinetics of which the clinician can modify using practical instruction within a clinical setting.MethodsGait analysis was performed in 51 patients following autologous chondrocyte implantation, during various partial- and full-weight-bearing conditions. The contribution of ground-reaction force, kinematic and spatio-temporal gait parameters to external-knee moments was investigated within weight-bearing levels less than 60%, between 60% and 90% and more than 90% of individual body weight.FindingsThere was no association between peak-ground-reaction force and the knee-adduction moment within the 60–90% and more than 90% weight-bearing conditions, nor the peak-knee-flexion moment at less than 60% weight-bearing. Peak-ground-reaction force accounted for no more than 21.4% and 18.6% of the variance in the knee-adduction and flexion moments, respectively, within any weight-bearing condition, while the combination of peak-ground-reaction force, kinematic and spatio-temporal parameters investigated accounted for no more than 39.7% and 52.2%, respectively. Foot-progression angle and knee-flexion during weight acceptance accounted for a significant (P < 0.05) portion of the variance in external-knee moments, particularly at higher levels of weight-bearing.InterpretationA large amount of variance in knee moments may be attributed to variables other than external loads, some of which can be modified by the clinician. Clinically, this is important for any therapist implementing progressive weight-bearing protocols.     

Adipocytokines attenuate the association between visceral adiposity and diabetes in older adults

OBJECTIVE: To examine whether adiponectin is independently associated with diabetes and whether adiponectin and other adipocytokines account for the relationship between fat and diabetes. RESEARCH DESIGN AND METHODS: A nested case-control study from the Health, Aging, and Body Composition (Health ABC) study. We measured four adipocytokines: adiponectin, interleukin (IL)-6, tumor necrosis factor-alpha, and plasminogen activator inhibitor 1 (PAI-1). Regional fat area was determined by computed tomography scan. The 519 case subjects had diabetes defined by fasting plasma glucose level > or =126 mg/dl or by use of diabetes medications. The 519 control subjects had normal glucose tolerance and were matched by sex, race, and study site. Sex-specific logistic models were adjusted for age, race, site, total adiposity, smoking, and physical activity. RESULTS: Higher adiponectin levels were associated with lower risk of diabetes (P < 0.001). Visceral fat was the only adiposity measure associated with diabetes after adjusting for BMI (odds ratio 3.0 [2.1-4.3] in women and 1.3 [1.0-1.6] in men, P < 0.001 between-sex comparison). Adipocytokines attenuated the association between visceral fat and diabetes for both sexes but more strongly in men (women 2.3 [1.5-3.3], men 1.1 [0.9-1.4]). In men, adiponectin, IL-6, and PAI-1 remained independently associated with diabetes after adjusting for fat depots; in women, adiponectin was the only independently associated adipocytokine. Controlling for insulin, HDL, triglycerides, and blood pressure did not change these results. CONCLUSIONS: Adiponectin is associated with lower odds of diabetes in older men and women. Whereas several adipocytokines explained the relationship between visceral adiposity and diabetes in men, only adiponectin partially mediated this association among women.     

Effects of lower leg muscle quality on gait variability in community-dwelling older and healthy young adults

[Purpose] We aimed to determine whether lower leg muscle echo intensity, an indicator of muscle quality, is a useful predictor of gait variability after examining the relationship between physical activity and gait variability in community-dwelling older and healthy young adults. [Participants and Methods] This study comprised two tasks. In the first task, 18 older and 25 young adults were included as participants. We examined the relationship between the amount of physical activity and gait variability in both groups. In the second task, muscle echo intensity related to gait variability in each group was measured using ultrasound echoes after identifying common factors related to gait variability in 19 older and 19 younger adults, and trends were compared. [Results] In the first task, gait variability was significantly higher in the younger group than in the older group. A significant negative correlation was found between the amount of physical activity and gait variability in both groups. In the second task, multiple regression analysis was performed for gait variability, and lower leg muscle echo intensity was identified as a significant factor. There was no difference in the correlation coefficient between gait variability and lower leg muscle echo intensity between the two groups. [Conclusion] Lower leg muscle quality was one of the causes of gait variability, suggesting that it is a useful predictor of gait sway status.     

The association between diabetes and cognitive changes during aging

Abstract

Background

Worldwide, we are observing a rising prevalence of dementia and mild cognitive impairments that often co-occur with the heightened incidence of non-communicable diseases in the elderly. It is suggested that type 2 diabetes and defects in glucose metabolism might predispose to poorer cognitive performances and more rapid decline in old age.     

Parental history of diabetes modifies the association between abdominal adiposity and hyperglycemia

OBJECTIVE: To examine whether the association between abdominal obesity and hyperglycemia differs according to the presence of a parental history of diabetes. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional study of 3,068 men and women, aged 20-65 years, without known diabetes who were fasting participants of a population-based study in three Dutch towns. Hyperglycemia was defined as a fasting plasma glucose concentration of 6.1 mmol/l (American Diabetes Association criterion). Waist circumference was categorized according to previously defined waist action levels. All estimates were adjusted for age and town. RESULTS: The regression coefficients for the association between waist circumference and fasting plasma glucose were larger in participants who had a parental history of diabetes than in those who did not (men beta = 0.31 vs. 0.16 mmol/SD, P [for interaction] = 0.003; women beta = 0.24 vs. 0.11 mmol/SD, P = 0.002). Furthermore, larger waist circumference (men > or = 94 vs. < 94 cm, women > or = 88 vs. < 80 cm) was associated with a greater excess prevalence of hyperglycemia in participants who had a parental history of diabetes than in those who did not (men 12.4 vs. 2.0%, P = 0.03; women 13.6 vs. 5.9%, P = 0.05). Adjustment for physical activity, alcohol intake, smoking, and educational level did not materially change the results. CONCLUSIONS: These findings indicate that the association between abdominal obesity and hyperglycemia is stronger in the presence of a parental history of diabetes. Blood glucose screening may be warranted at lower levels of waist circumference in individuals with a parental history of diabetes.     

The relationship between bilateral knee muscle strength and gait performance after stroke: the predictive value for gait performance

[Purpose] The purpose of this study was to assess the relationships between bilateral knee extension strengths and gait performance in subjects with poststroke hemiparesis and to predict gait performance by the paretic and nonparetic knee extension strength. [Subjects and Methods] This was a correlational study in which 238 consecutive inpatients with poststroke hemiparesis were enrolled. Knee extensor muscle strengths in paretic and nonparetic lower limbs were measured with a handheld dynamometer, and the presence or absence of impaired gait was also determined. [Results] The mean strength in the paretic lower limb was 0.90 Nm/kg, and that in the nonparetic lower limb was 1.24 Nm/kg. Discriminant analysis classified the difference between the possibility and impossibility of gait by knee extensor muscle strength (standardized discriminant coefficient: paretic, 1.32; nonparetic, 0.55). Thus, paretic and nonparetic knee extension strengths were integrated in the strength index. A threshold level of 2.0 provided the best balance between positive and negative predictive values for the strength index. [Conclusion] The results indicated that both paretic and nonparetic knee extension strengths were related to gait performance. The strength index deduced from bilateral knee extension strengths may serve as a clinically meaningful index for rehabilitation assessment and training.Key words: Stroke, Handheld dynamometer, Gait     

The association between muscle EMG and perfusion in knee extensor muscles

The relationships between electromyographic (EMG) activity and force as well as muscle blood flow and work have been well established. However, the association between muscle blood flow and EMG activity remains unsolved. Thus, to test the hypothesis that muscle EMG activity relates to muscle perfusion in different compartments of the quadriceps femoris (QF) muscle, 12 healthy male subjects were studied. During two very submaximal exercise bouts, at different exercise intensities, oxygen labelled radiowater and positron emission tomography were used to measure muscle perfusion. In addition, produced force of knee extensors and muscle EMG activity in the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles were recorded during both exercise bouts. Although the exercise intensity and average force production was higher during the second exercise bout (38 +/- 15 versus 51 +/- 17 N; P = 0.007), the mean EMG activity was lower (RF; P<0.001) or unchanged (VL; P = 0.722 and VM; P = 0.640). During the second exercise period, perfusion also remained unchanged in the entire QF muscle (P = 0.223) and in its separate muscles (VL, P = 0.703; VM, P = 0.141; RF, P = 0.113) in a group level. However, the individual changes in muscle perfusion were tightly related to changes in muscle EMG activity in VL (r = 0.84; P = 0.002) and VM (r = 0.68; P = 0.015) but poorly in the RF muscle (r = 0.40; P = 0.257). In conclusion, the different associations between muscle perfusion and EMG activity in different QF muscles suggests specific functional role of the vasti muscles and the RF muscle.