Arm Muscle Strength Research Articles

Trunk Strength Effect on Track Wheelchair Start

The T54 wheelchair racing class comprises athletes with normal arm muscle strength and trunk strength ranging from partial to normal. Paralympic sports classes should comprise athletes who have impairments that cause a comparable degree of activity limitation. On the basis of this criterion, the purpose of this study was to determine whether the T54 class is valid by assessing the strength of association between trunk strength and wheelchair acceleration. Participants were 10 male and 3 female international wheelchair track athletes with normal arm strength. Six were clinically assessed as having normal trunk strength, and seven had impaired trunk strength. Measures included isometric arm and trunk strength and distance covered at 1, 2, and 3 s in an explosive start from standstill on a regulation track, as well as on a custom-built ergometer with four times normal rolling resistance. No significant differences were observed between male athletes with and without full trunk strength in distance covered after 1, 2, and 3 s. Correlations between isometric trunk strength and wheelchair track acceleration were nonsignificant and low (0.27-0.32), accounting for only 7%-10% of variance in performance. Correlations between trunk strength and distance pushed under high resistance were also nonsignificant, although values were almost double (r = 0.41-0.54), accounting for 18%-28% of the variance in performance. These results provide evidence that impairment of trunk strength has minimal effect on wheelchair acceleration and indicate the T54 class is valid. Results do not infer that athletes with no trunk strength should compete with those who have partial or full trunk strength.

Comparison of the Effects of Ice and 3.5% Menthol Gel on Blood Flow and Muscle Strength of the Lower Arm

Soft-tissue injuries are commonly treated with ice or menthol gels. Few studies have compared the effects of these treatments on blood flow and muscle strength. To compare blood flow and muscle strength in the forearm after an application of ice or menthol gel or no treatment. Repeated measures design in which blood-flow and muscle-strength data were collected from subjects under 3 treatment conditions. Exercise physiology laboratory. 17 healthy adults with no impediment to the blood flow or strength in their right arm, recruited through word of mouth. Three separate treatment conditions were randomly applied topically to the right forearm: no treatment, 0.5 kg of ice, or 3.5 mL of 3.5% menthol gel. To avoid injury ice was only applied for 20 min. At each data-collection session blood flow (mL/min) of the right radial artery was determined at baseline before any treatment and then at 5, 10, 15, and 20 min after treatment using Doppler ultrasound. Muscle strength was assessed as maximum isokinetic flexion and extension of the wrist at 30°/s 20, 25, and 30 min after treatment. The menthol gel reduced (-42%, P < .05) blood flow in the radial artery 5 min after application but not at 10, 15, or 20 min after application. Ice reduced (-48%, P < .05) blood flow in the radial artery only after 20 min of application. After 15 min of the control condition blood flow increased (83%, P < .05) from baseline measures. After the removal of ice, wrist-extension strength did not increase per repeated strength assessment as it did during the control condition (9-11%, P < .05) and menthol-gel intervention (8%, P < .05). Menthol has a fast-acting, short-lived effect of reducing blood flow. Ice reduces blood flow after a prolonged duration. Muscle strength appears to be inhibited after ice application.

Resistance Arm Training in Patients With COPD: A Randomized Controlled Trial

The study aimed to evaluate the effect of upper extremity resistance training for patients with COPD on dyspnea during activity of daily living (ADL), arm function, arm exercise capacity, muscle strength, and health-related quality of life (HRQL).Patients were randomly assigned to an intervention or control group. The intervention group underwent arm resistance training. The control group performed a sham. Both groups exercised three times a week for 6 weeks. Dyspnea during ADL and HRQL were measured using the Chronic Respiratory Disease Questionnaire (CRDQ). Arm function and exercise capacity were measured using the 6-min pegboard and ring test (6PBRT) and the unsupported upper limb exercise test (UULEX), respectively. Muscle strength for the biceps, triceps, and anterior and middle deltoids was obtained using an isometric dynamometer.Thirty-six patients with COPD (66 ± 9 years) participated in the study. Compared with the control group, the magnitude of change in the intervention group was greater for the 6PBRT (P = .03), UULEX (P = .01), elbow flexion force (P = .01), elbow extension force (P = .02), shoulder flexion force (P = .029), and shoulder abduction force (P = .01). There was no between-group difference in dyspnea during ADL, HRQL, or symptoms during the 6PBRT or UULEX (all P values > .08).Resistance-based arm training improved arm function, arm exercise capacity, and muscle strength in patients with COPD. No improvement in dyspnea during ADL, HRQL, or symptoms was demonstrated.

Pre-Exercise Hypohydration Effects On Jumping Ability And Muscle Strength, Endurance And Anaerobic Capacity: A Meta-Analysis

A recent systematic review reported that pre-exercise hypohydration (PEH) impairs skeletal muscle performance. The extent to which PEH influences muscular performance-related outcomes remains to be quantified using standard meta-analytic procedures. PURPOSE: To determine the magnitude of the effects of PEH on leg and arm muscle strength, leg muscle endurance and anaerobic capacity, and jumping ability using a meta-analytic approach. METHODS: Studies were located via database searches and cross-referencing. Inclusion criteria: standard measures of muscular performance; hydration level in the euhydrated control group < 0.5% ≥ -1% bodyweight (BW); hypohydration level in the experimental group > 1% BW and > 0.5% than control BW. Exclusion criteria: diuretics- and caloric restriction-induced BW loss. Results were analyzed using a random-effect model for mean weighted summary effects and a random-effect analog to the ANOVA for subgroup analyses. RESULTS: Thirty-five research articles were retrieved, among which 11, 4, 7 and 4 met the inclusion criteria for muscle strength, muscle endurance, anaerobic capacity and jumping ability, respectively, providing 27, 7, 11 and 11 effect estimates. Mean BW decrease in experimental groups was 3.0 ± 1.4%, 3.2 ± 0.5%, 3.2 ± 1.2% and 2.5 ± 1.3% for muscle strength, muscle endurance, anaerobic capacity and jumping ability, respectively (range: 1.3 to 5.7%). Mean muscle strength fell by 4.6% (95% CI: 2.9 to 6.3%) with PEH relative to control, with leg (3.8%, 95% CI: 0.4 to 7.2%) and arm (4.8%, 95% CI: 2.9 to 6.8%) strength declining similarly. PEH resulted in a mean decrease in muscle endurance of 11.7% (95% CI: 0.002 to 23.4%) and a decline in anaerobic capacity by 5.7% (95% CI: 1.5 to 9.9%). When pooled together, results of studies indicated that the decline in muscular performance is not significantly different between studies with BW losses ≤ or > 3%. PEH did not alter jumping ability compared with control. CONCLUSIONS: PEH of 1.5 to 5.5% BW does not affect jumping ability, but decreases leg (-4%) and arm (-5%) muscle strength, as well as leg muscle endurance (-12%) and anaerobic capacity (-6%) in a significant and practical manner. The opinions or assertions contained herein should not to be construed as official or reflecting the views of the Army or the DoD.

Rehabilitation System Using Teleoperation with Force-Feedback-Based Impedance Adjustment and EMG-Moment Model for Arm Muscle Strength Assessment

In this paper, at first, a teleoperation robot systemwith haptic feedback for rehabilitation is presented. A teleoperation mechanism capable of providing force feedback by means of adjusting the system’s impedance is proposed. The stability of the teleoperation with haptic feedback via a time-delay communication environment is mathematically proved. The proposal operates theoretically with both passive and active assisted movement using teleoperation to rehabilitate of upper limb function. An EMG-moment arm model is proposed for assessing muscle strength. The performance of a two-joint link model using six muscles and a nonlinear relationship between EMG signals and muscle force is confirmed feasible in experiments with five subjects.

Predictors of partial weight-bearing performance after total hip arthroplasty

To determine which patient characteristics, postoperative characteristics, and walking features influence patients' partial weight-bearing performance after total hip arthroplasty. A descriptive prospective study. Fifty patients with total hip arthroplasty were included; partial weight-bearing was performed at a 10% body weight target load (n=33) and at a 50% body weight target load (n=17). Patient (age, gender, body weight, upper arm muscle strength) and postoperative (pain, fatigue, anxiety) characteristics, and walking features (step frequency, total walking time, total number of steps, walking aid) were measured postoperatively on day 7 (with and without a physical therapist) and on day 21 (at home). Multilevel regression analyses were conducted to identify determinants that influence partial weight-bearing. Gender (female) (regression coefficient B=8.18, p=0.03) and total walking time (B=0.58, p<0.001) were positively, and pain during walking was negatively (B=-2.43, p=0.02), associated with the mean peak load. For partial weight-bearing at 10% body weight, postoperative overall anxiety (B=6.40, p=0.002) and total steps (B=0.05, p=0.02) were positively associated with the percentage of steps above the target load. For partial weight-bearing at home, postoperative overall anxiety was negatively associated with the percentage of steps above the target load (B=-5.32, p=0.001). Gender, pain during walking, walking time, postoperative anxiety and total number of steps influence the patient's partial weight-bearing performance.

Physical training combined with dietary measures in the treatment of adult obesity. A comparison of two protocols

Objective Our objective was to study the effects of physical training combined with dietary measures in obese adults. In a second step, we sought to compare two training protocols and establish the additional contribution of strength training. Methods We performed a randomized, prospective survey from July 2004 to November 2007. Included patients were randomized into three groups: a control group (G1), a group (G2) performing dietary measures and a programme of treadmill training at 60% of each individual's maximum heart rate (HR max) and a group (G3) who followed the G2 programme supplemented with strength training. All patients underwent an initial and final assessment of anthropometric & cardiovascular parameters, muscle strength, dyspnoea during activities of daily living, metabolic disorders, psychological status and quality of life. Results The greatest weight loss (7.24%) was observed in G3. Reduction in waistline measurement (WL) of 4.3% and 10.26% were noted in G2 and G3, respectively ( p < 0.001). The percentage fat body mass fell by 10.4% in G3 ( p < 0.001) and 8.6% in G2 ( p = 0.03). We particularly noted an improvement in physical condition in groups 2 and 3, with lower HR and blood pressure values at rest and at maximum effort. The overall improvement in both arm and leg muscle strength was greater for G3 than for G2. Likewise, we noted an improvement in the metabolic parameters and depression & anxiety scores for the trained groups (G2, G3), relative to the control group (G1). We also noted improvements in the total impact of weight on quality of life (IWQOL) lite score of 15.2% in G2 and 18% in G3. Conclusion Our survey demonstrated the beneficial effect of combining dietary measures and physical training in obese patients. In addition to weight loss, the programme enabled a reduction in the patients’ body fat mass and abdominal obesity, a correction of metabolic disorders and an improvement in aerobic capacity. The improvement in all these parameters also enhanced the patients’ psychological status and quality of life. The addition of strength training produced notable improvements in weight loss, arm muscle strength and abdominal obesity.

Central core disease and susceptibility to malignant hyperthermia in a single family

Sirs: Central core disease (CCD) is a rare congenital myopathy whose phenotype ranges from asymptomatic to severe muscle weakness. Histologically, type I skeletal muscle fibres predominate and show amorphous myofibrillar cores lacking mitochondria and oxidative enzyme activity. Clinical manifestations include hypotonia, delayed motor milestones, proximal muscle weakness, and skeletal anomalies [3, 5]. CCD is usually autosomal dominant with variable penetrance, but can be autosomal recessive [4]. CCD is usually associated with mutations in the ryanodine receptor gene (RYR1), which encodes a homotetrameric Ca-release channel (RyR1) of the sarcoplasmic reticulum crucially involved in excitationcontraction coupling [1, 9]. RYR1 mutations are also associated with malignant hyperthermia susceptibility (MH) and certain forms of the usually recessive multiminicore disease (MmD). About 41% of known RYR1 mutations produce MH, are located in the N-terminal (cytoplasmic) or central region (transmembrane) of the homotetramer, and recur sporadically. CCD-producing mutations are mainly confined to a few families and localize in the C-terminal (also cytoplasmic) domain [5, 7, 8, 10]. We describe two sisters with CCD and their asymptomatic consanguineous parents. The daughters were homozygous and the parents heterozygous for an RYR1 mutation. A 36-year-old woman and her 31-year-old sister were referred to us in 2007 for genetic counselling. We had seen them during childhood for early onset hypotonia and muscle weakness, with delayed motor milestones, and mild deterioration of motor abilities as childhood progressed. There was no family history of neuromuscular disease, but the parents were first cousins (Fig. 1a). Quadriceps needle biopsies from each sister had shown variable fibre size and central nuclei. Oxidative enzyme staining had shown one or more large cores in most fibres (Fig. 2) and type I fibre predominance. CCD was diagnosed. In 2007 the sisters had closely similar phenotypes: elongated face, congenital hip dislocation, foot deformities (repaired surgically during childhood), and thoraco-lumbar scoliosis. There was mild facial muscle weakness, scapular winging, normal arm muscle strength, but evident weakness of lower limb muscles; external ophthalmoplegia was absent. Neither sister could run; they could rise from the floor with difficulty using Gower’s manoeuvre, and climb stairs using a handrail. Serum creatine kinase and respiratory function were normal. Electromyography showed myopathic findings. The parents were asymptomatic with normal neurological examination; they refused muscle biopsy. After receiving written informed consent from each family member, genomic DNA from peripheral blood was screened for RYR1 mutations by PCR and sequencing. The sisters (II1 and II2) were homozygous for c.11708G[A mutation in exon 85 resulting in R3903Q substitution (arginine to glutamine); the parents (I1 and I2) were heterozygous for the same mutation (Fig. 1b). Galli et al. [2] described the same heterozygous mutation associated with MH. Our data suggest that this mutation causes classic CCD only when inherited homozygously, as in our sisters, since the heterozygous parents L. Colleoni G. Melli L. Morandi P. Cudia S. Romaggi R. Mantegazza P. Bernasconi (&) Neurology IV, Neuromuscular Diseases and Neuroimmunology, Neurological Institute Foundation ‘‘Carlo Besta’’, Via Celoria 11, 20133 Milan, Italy e-mail: pbernasconi@istituto-besta.it

Relação entre ciclo menstrual e planejamento dos treinos: um estudo de caso

This case study had as objective to verify the relation between tennis training and the menstrual cycle of a 17-year-old athlete. The training period lasted 16 weeks. Performance tests were carried out in two instances during the ovulation period of the menstrual cycle of the investigated athlete. Motor skills specific to tennis were analyzed: speed, arm muscle strength, leg muscle strength and agility. The results demonstrated a considerable improvement in all variables. Therefore, it is suggested that a guided plan, based of the principle of individuality, will be able to guide training loads and seek better results. However, monitoring is necessary in the different periods of the menstrual cycle, using a larger population sample, in the search for answers to other factors related to menstruation and exercise.

TNF promoter polymorphisms associated with muscle phenotypes in humans

Tumor necrosis factor-alpha (TNF-alpha) is a potent catabolic factor to skeletal muscle. Single-nucleotide polymorphisms (SNPs) in the promoter region of the TNF-alpha coding gene, TNF, have been implicated in the interindividual variation in TNF-alpha production via transcriptional regulation. The present study investigated the association of muscle phenotypes with five TNF promoter SNPs, which potentially have biological significance. Female and male volunteers (n = 1,050) from the Baltimore Longitudinal Study of Aging were genotyped, and their regional and total body muscle mass, and arm and leg muscle strength were measured. Results indicated that putative high-expression alleles at positions -1031 and -863, individually or in combination in the haplotype 1031C-863A-857C-308G-238G, were associated with lower muscle mass in men. Specifically, carriers of -1031C, compared with noncarriers, exhibited lower arm muscle mass (6.4 +/- 0.1 vs. 6.8 +/- 0.1 kg, P = 0.01) and appendicular skeletal muscle mass (ASM) (24.3 +/- 0.4 vs. 25.4 +/- 0.2 kg, P = 0.02), with leg muscle mass and the ASM index (ASMI; kg/m(2)) also tending to be lower (P = 0.06 and 0.07). Similarly, -863A allele carriers (linked with -1031), compared with noncarriers, exhibited lower arm muscle mass (6.4 +/- 0.1 vs. 6.8 +/- 0.1 kg, P = 0.04). Carriers of the haplotype 1031C-863A-857C-308G-238G, compared with noncarriers, exhibited lower arm muscle mass (6.3 +/- 0.2 vs. 6.8 +/- 0.1 kg, P < 0.01), trunk muscle mass (25.7 +/- 0.5 vs. 26.9 +/- 0.3 kg, P < 0.05), and ASM (24.1 +/- 0.5 vs. 25.3 +/- 0.2 kg, P < 0.025), with tendencies for lower leg muscle mass and ASMI (P = 0.07 and 0.08). Results indicate that genetic variation in the TNF locus may contribute to the interindividual variation in muscle phenotypes in men.

Neurobrucellosis mimicking demyelinizating disorders

imagesNeurobrucellosis mimicking demyelinizating disorders Ilkay Karaoglan, Aylin Akcali, Ayhan Ozkur, and Mustafa Namýduru Ilkay Karaoglan Department of Infectious Disease, Gaziantep University, Medical Faculty, Gaziantep, Turkey Search for more papers by this author , Aylin Akcali Department of Neurology, Gaziantep University, Medical Faculty, Gaziantep, Turkey Search for more papers by this author , Ayhan Ozkur Department of Radiology, Gaziantep University, Medical Faculty, Gaziantep, Turkey Search for more papers by this author , and Mustafa Namýduru Department of Infectious Disease, Gaziantep University, Medical Faculty, Gaziantep, Turkey Search for more papers by this author Published Online:3 Apr 2008https://doi.org/10.5144/0256-4947.2008.148SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutIntroductionA 25-year-old female was admitted because of fever, backache, headache, confusion, convulsion, left hemiparesis, nausea and urinary incontinance. She was diagnosed as having multiple sclerosis and received intravenous pulse corticosteroids (1000 mg/day) for 5 days. Three weeks later, she did not improve and was transfered to our hospital. She had no history of contact with unpasteurized milk or milk products. On the physical exam, her temperature was 38°C, she was alert and cooperative, her left leg and arm muscle strength was 3/5, she had features of neck stiffness, and Kernig and Brudzinski signs. Her white blood cell count was 11.95 ×109/L, hemoglobin was 101 g/L, erythrocyte sedimentation rate was 40 mm/h, lactate dehydrogenase was 607 U/L, and C-reactive protein was 19.9 mg/L. The serum Brucella agglutination test was positive at 1:640 titers. A lumbar puncture was performed; for the opening pressure was 280 mm Hg, 136 lymphocytes per mm3, 34 polymorphs per mm3, with 129 mg/dL protein, 33 mg/dL glucose (serum glucose was 95 mg/dL). The CSF oligoclonal band was negative. Brucella agglutination in CSF was 1:80 titers (positive). Brucella species grew in the CSF culture. In several blood cultures collected from the patient, Brucella species were obtained in one. The TORCH panel On the CSF was negative. Cranial MRI revealed a heterogeneous well-demarcated lesion, a right crus cerebri lesion and multiple hyperintense lesions. After contrast material administration, the lesion (crus cerebri) showed ring-type enhancement (Figure 1), and peripherally to the central enhancing spot, a faint ill-defined parenchymal enhancement was present. The patient had a repeat MRI of the brain 1 month after treatment and these images showed a marked improvement in the suprasellar granulomatous formation (Figure 2).Figure 1 (A) Axial FLAIR image shows the edematous changes of the right crus cerebri lesion, (B) post-contrast T1- weighted axial image showing ringlike enhancement of the lesion and pathologic enhancement within parenchyma.Download FigureFigure 2 Gadolinium-enhanced T1-weighted brain MR images obtained 1 month after treatment showing resolution of the granuloma.Download FigureThe patient was treated with doxycycline, rifampicin and trimethoprim-sulfamethoxazle. After 2 weeks, urinary incontinance, and hemiparesis on the left leg and arm improved. After 8 weeks, there was 1/5 motor dysfunction on the left arm and leg. A follow-up lumbar puncture was performed and the opening pressure, protein, and glucose were within normal limits. The lymphocyte count was 60 cells/mm3. Brucella agglutination in CSF was 1:20 titer (positive). After two months a repeat cranial MRI showed a marked reduction in the size of the lesions. The patient recovered from neurobrucellosis with minimal sequelae. Previous article Next article FiguresReferencesRelatedDetails Volume 28, Issue 2March-April 2008 Metrics History Accepted1 December 2007Published online3 April 2008 InformationCopyright © 2008, Annals of Saudi MedicineThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.PDF download

Functional independence and health-related functional status following spinal cord injury: A prospective study of the association with physical capacity

To determine changes in functional independence following spinal cord injury and to evaluate the association between functional independence and physical capacity. Multi-centre prospective cohort study. Patients with spinal cord injury admitted for initial rehabilitation. The motor Functional Independence Measure (FIMmotor) was determined at the start of rehabilitation (n = 176), 3 months later (n = 124), at discharge (n = 160) and one year after discharge from inpatient rehabilitation (n = 133). One year after discharge, physical and social dimensions of health-related functional status (Sickness Impact Profile 68; SIP68) were determined. On each occasion, physical capacity was established by measuring arm muscle strength, peak power output and peak oxygen uptake. Multi-level random coefficient analyses revealed that FIMmotor improved during inpatient rehabilitation, but stabilized thereafter. Changes in FIMmotor were associated with peak power output. Multiple regression models showed that FIMmotor and peak power output at discharge were associated with FIMmotor one year after discharge (R2 = 0.85), and that peak power output at discharge was associated with the social dimension of the SIP68 (R2 = 0.18) one year after discharge. Functional independence improves during inpatient rehabilitation, and functional independence is positively associated with peak power output.

Prognostic Models for Physical Capacity at Discharge and 1 Year Postdischarge From Rehabilitation in Persons With Spinal Cord Injury

Haisma JA, van der Woude LH, Stam HJ, Bergen MP, Sluis TA, de Groot S, Dallmeijer AJ, Bussmann JB. Prognostic models for physical capacity at discharge and 1 year postdischarge from rehabilitation in persons with spinal cord injury. Objective To develop prognostic models for physical capacity at discharge and 1 year after discharge from inpatient rehabilitation in persons with spinal cord injury (SCI). Design Inception cohort; data collected at start of rehabilitation (n=104), at discharge (n=81), and 1 year later (n=74). Setting Eight Dutch rehabilitation centers. Participants Patients with SCI at initial rehabilitation. Interventions Not applicable. Main Outcome Measures Physical capacity determined by endurance capacity (peak oxygen uptake [V o 2peak, in L/min] and power output [POpeak, in watts]) during a maximal exercise test, arm muscle strength, and respiratory function. Multiple regression models, either with or without prior outcome, evaluated subject, lifestyle, and lesion-related predictors. Results Only start V o 2peak contributed to the prediction of discharge V o 2peak ( R 2=.51). Discharge V o 2peak contributed to its prediction 1 year later ( R 2=.75). Start POpeak, sex, age, and level of lesion contributed to discharge POpeak ( R 2=.73). Discharge POpeak, hours of employment before injury, and level of lesion contributed to POpeak 1 year later ( R 2=.81). Models without prior outcome explained less variance. Education, employment, body mass index, not smoking, and conservative stabilization of the spine positively contributed to endurance capacity. Muscle strength was well predicted ( R 2 range, .68−.84). Without prior outcome, respiratory function was poorly predicted. Conclusions Because prior outcome contributed to an accurate prediction, the early assessment of physical capacity is important in establishing prognoses. Although their accuracy warrants caution in their application, models could complement clinical expertise when informing patients about expected physical outcome and identifying those at risk of low physical capacity.

Accelerated Loss of Skeletal Muscle Strength in Older Adults With Type 2 Diabetes

It has been shown that adults with either long-standing type 1 or type 2 diabetes had lower skeletal muscle strength than nondiabetic adults in cross-sectional studies. The aim of the study was to investigate longitudinal changes of muscle mass and strength in community-dwelling older adults with and without type 2 diabetes. We examined leg and arm muscle mass and strength at baseline and 3 years later in 1,840 older adults aged 70-79 years in the Health, Aging, and Body Composition Study. Regional muscle mass was measured by dual energy X-ray absorptiometry, and muscle strength was measured using isokinetic and isometric dynamometers. Older adults with type 2 diabetes (n = 305) showed greater declines in the leg muscle mass (-0.29 +/- 0.03 vs. -0.23 +/- 0.01 kg, P < 0.05) and strength (-16.5 +/- 1.2 vs. -12.4 +/- 0.5 Nm, P = 0.001) compared with older adults without diabetes. Leg muscle quality, expressed as maximal strength per unit of muscle mass (Newton meters per kilogram), also declined more rapidly in older adults with diabetes (-1.6 +/- 0.2 vs. -1.2 +/- 0.1 Nm/kg, P < 0.05). Changes in arm muscle strength and quality were not different between those with and without diabetes. Rapid declines in leg muscle strength and quality were attenuated but remained significant after controlling for demographics, body composition, physical activity, combined chronic diseases, interleukin-6, and tumor necrosis factor-alpha. In older adults, type 2 diabetes is associated with accelerated loss of leg muscle strength and quality.

Isometric Muscle Torque in Children 5 to 15 Years of Age: Normative Data

Nyström Eek M, Kroksmark A-K, Beckung E. Isometric muscle torque in children 5 to 15 years of age: normative data. Objective To establish reference values of arm and leg muscle strength as measured by isometric torque production in healthy children. Design Measurement of isometric muscle strength in healthy children. Setting Public school. Participants Healthy children (N=149; 76 boys, 73 girls) ages 5 to 15 years. Interventions Not applicable. Main Outcome Measures Isometric torque values of 12 arm and leg muscle groups of healthy children as measured by a handheld dynamometer. Results Normative data were obtained for children 5 to 15 years of age. There was an increase in torque with age and weight and a strong correlation with both age and weight. There were few differences between boys and girls. Equations for predicted torque taking into account age, weight, and sex were calculated. The agreement between examiners was excellent. Conclusions Studies on growing children require comparison to healthy (normal) children to assess the amount of deviation from normal and to be able to draw conclusions of change over time. The reference values for torque in combination with a predicted value based on the child’s age, weight, and sex make it possible to compare over time and between subjects and provide a tool for evaluation of physical status and efficacy of therapy.

Effects of Aerobic and Resistive Exercise Training on Glucose Disposal and Skeletal Muscle Metabolism in Older Men

Aging is associated with insulin resistance, primarily as a result of physical inactivity and increased abdominal obesity. We hypothesized that aerobic (AEX) or resistive (RT) exercise training would result in comparable improvements in glucose disposal in older men, but that there would be different metabolic adaptations in skeletal muscle. Thirty-nine older (63+/-1 years, mean+/-standard error of the mean), overweight and obese (body mass index=30.3+/-0.4 kg/m2) men were assigned to AEX (treadmill walking and/or jogging, n=19) or RT (upper and lower body, n=20) programs 3 d/wk for 6 months, with 9 completing AEX and 13 completing RT. Testing before and after the exercise programs included body composition, euglycemic-hyperinsulinemic clamps, and vastus lateralis muscle biopsies. Maximal oxygen consumption (VO2max) increased by 16% after AEX (p<.01), while leg and arm muscle strength increased by 45+/-5% and 27+/-5% after RT (p<.0001). Although participants were monitored to maintain their body weight during the exercise program, body weight decreased by 2% after AEX (p<.05), and increased by 2% after RT (p<.05). Whole-body glucose disposal, determined during the last 30 minutes of a 2-hour 480 pmol/m2/min euglycemic-hyperinsulinemic clamp, increased comparably by 20%-25% after AEX (51+/-5 to 61+/-5 microM/kgfat-free mass/min, p<.05) and RT (49+/-3 to 58+/-3 microM/kgfat-free mass/min, p<.05). The increase in vastus lateralis muscle glycogen synthase fractional activity in response to insulin stimulation was significantly higher after AEX compared to after RT (279+/-59% compared to 100+/-28% change, p<.05). Neither AEX nor RT altered muscle glycogen synthase total activity, glycogen content, or levels of phosphotidylinositol 3-kinase. These results suggest that AEX and RT result in comparable improvements in glucose metabolism in older men, whereas an increase in insulin activation of glycogen synthase occurred only with AEX. These improvements in insulin sensitivity could reduce the risk of metabolic syndrome and type 2 diabetes and attenuate the development of cardiovascular disease.

Fall risk factors and the nature of falls in inpatient oncology and palliative care settings

Using a prospective design, this study examined falls risk factors and the nature of patient falls in oncology and palliative care settings. Two hundred and twenty seven patients admitted to the oncology and palliative care units at a private hospital participated in this study. Of these, 34 patients had a fall and 193 patients did not have a fall.Twenty–four nurses who attended to patients who fell were interviewed. Findings revealed that, when compared to patients who did not fall, fallers had a significantly higher mean age; were assessed as more physically dependent using the Eastern Cooperative Oncology Group scale; were less alert and more confused; were more likely to have responded incorrectly to orientation to person, time and place; were weaker pre-fall in arm muscle strength; and were more fatigued. These factors are worthy of further exploration to determine whether they are more sensitive than the currently used falls risk factors used in oncology and palliative care settings.

Anaerobic muscle performance of children after long-term recovery from Guillain-Barré syndrome.

The aim of this study was to evaluate anaerobic muscle performance in children after long-term recovery from Guillain-Barré syndrome (GBS). Participants were recruited from all children and adolescents with GBS admitted to The Hospital for Sick Children, University of Toronto, Canada, between 1988 and 1995. We assessed 17 children (nine males, eight females; mean age at GBS diagnosis 7 years 11 months, SD 4 years 2 months; mean age at testing 14 years 1 month) more than two years after acute GBS. Participants completed the Wingate anaerobic test to evaluate mean and peak muscle power. For mean arm muscle power (mean 47.5% [SD 17.4%] of normal), only two participants were in the normal range. For mean leg muscle power (mean 83% [SD 28.3%] of normal), 15 participants were in the normal range. For arm peak power (mean 92.6% [SD 20.7%] of normal), 12 participants were in the normal range. For leg peak power (mean 116.3% of normal, SD 15.8%), all participants were in the normal range. Detailed manual muscle testing with the modified Medical Research Council scale was done on 34 muscle groups. Data were pooled to give a mean arm and leg muscle strength score (9.7, SD 0.30 and 9.4, SD 0.50 respectively). Pearson's correlations of muscle endurance with arm and leg strength were not significant. Children with GBS have excellent long-term recovery of peak muscle power. Muscle endurance, measured by mean muscle power, was normal in the legs but markedly low in the arms. Pediatric rehabilitation programs after GBS should specifically target endurance of arm muscles.

The ER22/23EK polymorphism in the glucocorticoid receptor gene is associated with a beneficial body composition and muscle strength in young adults.

Glucocorticoids play an important role in determining body composition. A polymorphism of the glucocorticoid receptor gene (in codons 22 and 23) has previously been found to be associated with relative glucocorticoid resistance, low cholesterol levels, and increased insulin sensitivity. In this study, we investigated whether this ER22/23EK polymorphism is associated with differences in body composition and muscle strength. We studied a cohort of 350 subjects who were followed from age 13 until 36 yr. We compared noncarriers and carriers of the ER22/23EK variant in anthropometric parameters, body composition, and muscle strength, as measured by arm pull tests and high jump from standing. We identified 27 (8.0%) heterozygous ER22/23EK carriers. In males at 36 yr of age, we found that ER22/23EK carriers were taller, had more lean body mass, greater thigh circumference, and more muscle strength in arms and legs. We observed no differences in body mass index or fat mass. In females, waist and hip circumferences tended to be smaller in ER22/23EK carriers at the age of 36 yr, but no differences in body mass index were found. Thus, the ER22/23EK polymorphism is associated with a sex-specific, beneficial body composition at young-adult age, as well as greater muscle strength in males.

Biomechanical simulations of forward fall arrests: effects of upper extremity arrest strategy, gender and aging-related declines in muscle strength

Computer simulation was used to predict the extent to which age-related muscle atrophy may adversely affect the safe arrest of a forward fall onto the arms. The biomechanical factors affecting the separate risks for wrist fracture or head impact were examined using a two-dimensional, 5-link, forward dynamic model. The hypothesis was tested in older females that age-related loss in muscular strength renders the use of the arms ineffective in arresting a forward fall without either a torso impact exceeding 0.5 m/s or distal forearm loads sufficient to fracture the wrist. The results demonstrate that typical age-related decline in arm muscle strength substantially reduces the ability to arrest a forward fall without the elbows buckling and, therefore, a risk of torso and/or head impact. The model predicted that older women with below-average bone strength risk a Colles fracture when arresting typical falls, particularly with an extended arm.