Diagnostic accuracy, validity, and reliability of Tensiomyography to assess muscle function and exercise-induced fatigue in healthy participants. A systematic review with meta-analysis.

Tensiomyography™ (TMG) is a non-invasive method to monitor skeletal muscle mechanical characteristics. This systematic review and meta-analysis reports on diagnostic accuracy, validity, and reliability of TMG (maximal radial displacement [Dm], contraction time [Tc], delay time [Td], and velocity of contraction [Vc]) to assess exercise-induced fatigue in healthy volunteers, with the specific aim to determine the current level of supporting evidence. Systematic literature searches within Medline, Embase and Sportdiscus databases were conducted from January 1990 through November 2018. Methodological quality was evaluated by the Assessment of Diagnostic Accuracy Studies (QUADAS) tool or the Validity and Reliability Critical Appraisal Tool (CAT) or the Quality Appraisal of Diagnostic Reliability checklist (QAREL). Meta-analytical methods were utilised to summarize relative reliabilities of Dm, Tc, Td (95%, CI). The methodological quality of the 19 included studies (n = 373; female = 13.0%) ranged from low to high quality. The analysis revealed insufficient diagnostic accuracy and validity, mixed results regarding absolute reliability, and high to excellent relative reliability for the assessed measures. To conclude, robust evidence for diagnostic accuracy/validity of TMG has yet to be determined, whereas there is substantial evidence for its reliability. Higher methodological standards need to be established, including the avoidance of gender bias.

Improving Running Economy by Transitioning to Minimalist Footwear: A Randomised Controlled Trial.

OBJECTIVES: Ongoing debates about benefits and risks of barefoot- and minimally-shod running have, to date, revealed no conclusive findings for long-term effects on physical performance. The purpose of this study was to examine the effects of an 8-week transition to minimalist footwear (MFW) on running economy (RE). DESIGN: Randomised controlled trial. METHODS: Thirty-two male, habitually-shod runners were assigned randomly to an 8-week training intervention either in minimalist (=intervention group) or conventional running shoes (=control group). The intervention consisted of a gradual increase in use of the new footwear by 5% of the individual weekly distance. Before and after the intervention, a VO2max test was followed by a submaximal RE test at 70% and 80% of vVO2max in both shoe conditions 7days later. RE was measured at the submaximal tests and expressed as caloric unit cost (kcalkg-1km-1) and oxygen consumption (mlkg-1km-1). RESULTS: RE improved in the intervention group over time compared to the control group with small to moderate effect sizes (ES) in both shoe conditions: Effects on RE (kcalkg-1km-1) in conventional running shoes: ES vVO270%: 0.68 (95% CI: -0.14 to 1.51), ES vVO280%: 0.78 (95% CI: 0-1.56). In minimalist footwear: ES vVO270%: 0.3 (95% CI: -0.54 to 1.14), ES vVO280%: 0.42 (95% CI: -0.41 to 1.25). These effects were not statistically significant (p>0.05). The repeated-measures ANOVA also showed no group by time interactions for all submaximal RE testing conditions (p>0.05). CONCLUSIONS: Although not reaching statistical significance, training in MFW compared to CRS resulted in small to moderate improvements in RE.

[Physician Counseling about Physical and Sports Activity in Neurological Practices in Germany: Results of a Survey Among Members of the German Neurological Society]. / Beratung zu körperlicher und sportlicher Aktivität in neurologischen Praxen in Deutschland. Ergebnisse einer Umfrage unter den Mitgliedern der Deutschen Gesellschaft für Neurologie e.V.

Physical inactivity is a major but modifiable risk factor for morbidity and mortality. Regular physical activity has preventive and therapeutic effects on numerous diseases including neurological disorders. Therefore, it is desirable that physicians motivate their patients to increase their physical and sports activities and that they help them to overcome barriers to exercising. The present study is a survey of neurologists who are members of the German Neurological Society with their own practices; they were asked whether they advised their patients on the benefits of physical activity. Details on physician counseling on physical activity were obtained, such as the frequency of counseling, the neurological disorders considered by the practitioners to be worth the effort of counseling, and the barriers to exercise on the part of patients. More than 80 % of the participants who responded to the survey stated that they frequently provide their patients with advice on the preventive and therapeutic aspects of physical activity. Almost all of them recommended endurance sports; this was followed by Far Eastern types of sport such as tai chi or yoga (70 % of all physicians who advice sports activities). The frequency of counseling about physical activity significantly correlated to the physician's own sports activity. Frequency of counseling was reduced if the physician assessed the patients to be incapable of adopting and maintaining a lifestyle of habitual physical activity. Lack of time as well as an insufficient reimbursement of the counseling, however, did not significantly influence the frequency of counseling. The physician's own sports activity matched that of individuals with similar social status. Thus, a selection bias does not seem to be of importance regarding the results of the survey. However, since only 169 of the 784 invited neurologists (21.6 %) responded to the questionnaire, the representativeness of the survey may be limited. Counseling about physical activity seems to be an essential part of consultations in neurological practices.

Video raster stereography back shape reconstruction: a reliability study for sagittal, frontal, and transversal plane parameters.

PURPOSE: As reliability of raster stereography was proved only for sagittal plane parameters with repeated measures on the same day, the present study was aiming at investigating variability and reliability of back shape reconstruction for all dimensions (sagittal, frontal, transversal) and for different intervals. METHODS: For a sample of 20 healthy volunteers, intra-individual variability (SEM and CV%) and reliability (ICC ± 95% CI) were proved for sagittal (thoracic kyphosis, lumbar lordosis, pelvis tilt angle, and trunk inclination), frontal (pelvis torsion, pelvis and trunk imbalance, vertebral side deviation, and scoliosis angle), transversal (vertebral rotation), and functional (hyperextension) spine shape reconstruction parameters for different test-retest intervals (on the same day, between-day, between-week) by means of video raster stereography. RESULTS: Reliability was high for the sagittal plane (pelvis tilt, kyphosis and lordosis angle, and trunk inclination: ICC > 0.90), and good to high for lumbar mobility (0.86 < ICC < 0.97). Apart from sagittal plane spinal alignment, there was a lack of certainty for a high reproducibility indicated by wider ICC confidence intervals. So, reliability was fair to high for vertebral side deviation and the scoliosis angle (0.71 < ICC < 0.95), and poor to good for vertebral rotation values as well as for frontal plane upper body and pelvis position parameters (0.65 < ICC < 0.92). Coefficients for the between-day and between-week interval were a little lower than for repeated measures on the same day. Variability (SEM) was less than 1.5° or 1.5 mm, except for trunk inclination. Relative variability (CV) was greater in global trunk position and pelvis parameters (35-98%) than in scoliosis (14-20%) or sagittal sway parameters (4-8 %). CONCLUSIONS: Although we found a lower reproducibility for the frontal plane, raster stereography is considered to be a reliable method for the non-invasive, three-dimensional assessment of spinal alignment in normal non-scoliotic individuals in the sagittal plane and partly for scoliosis parameters, which fulfils scientific as well as practical recommendations for spine shape screening and monitoring, but cross-sectional or follow-up effect analyses should take into account the degree of reliability differing in various spine shape parameters. Further investigations should be conducted to analyse reliability in scoliosis patients with differing spinal deformities.

[Spinal form and function profile: reference values for clinical use in low back pain]. / Wirbelsäulenform- und Funktionsprofile: Referenzwerte für die klinische Nutzung bei Rückenschmerzsyndromen.

BACKGROUND: Functional diagnostic approaches are helpful in the treatment of low back pain (LBP) patients. Reference data of asymptomatic individuals might be helpful to understand individual case profiles of LBP patients, to derive movement therapy goals and issues and to improve quality management in therapy monitoring. METHODS: Spinal form and mobility in the dorsal flexion (static and dynamic rasterstereography), as well as isometric peak forces (back extension/trunk flexion) were analyzed in a cross-sectional study of 103 pain-free volunteers (52 females, 51 males) aged 18-40 years. RESULTS: Reference data could be demonstrated based on percentiles (5-95 %). There were significant differences between males and females for strength values and spinal form parameters describing the lumbosacral transition (p < 0.001), but not for the strength extension/flexion ratio (Ex/Flex), lumbar mobility (dorsiflexion) or any other spine shape parameter. CONCLUSION: Despite the problem of a normal spinal alignment it is proposed to use reference data percentiles of asymptomatic persons to construct a musculoskeletal functional profile for individual LBP patients, which might emphasize the character of different LBP disorders and could be useful in screening, therapy planning and monitoring.

Do responses to exercise training in cystic fibrosis depend on initial fitness level?

The aim of our study was to evaluate the responses to an exercise programme with respect to initial fitness in subjects with cystic fibrosis (CF). 72 subjects (42 female) aged 10-43 yrs (forced expiratory volume in 1 s of 62.0 ± 26.7% predicted) were included. Participants were divided into three groups based on peak oxygen uptake expressed as % predicted. Subjects participated in a multifaceted rehabilitation programme, including five-times-a-week exercise training, for 6 weeks. Exercise and ventilatory capacity were determined by a maximal incremental cycling test. Oxygen uptake, workload and peak cardiac frequency at peak and submaximal workload were used as parameters for exercise capacity and responsiveness to training. Lung function values were significantly different between groups (p < 0.05), and increased after training (p < 0.05) only in groups with a lower initial fitness level. Responsiveness to training showed differences between groups (p < 0.05) at peak and ventilatory anaerobic threshold (VAT; p < 0.05), with higher improvements in subjects with lower initial fitness level. The improvements in exercise parameters in CF at peak and VAT depended on the fitness level at baseline, independent of lung function. These improvements seen after training were comparable with those seen in healthy subjects, suggesting that responsiveness to exercise is similar in CF and in healthy untrained persons.

[Heart rate measurement for determination of training intensity in outpatient pulmonary sport groups]. / Herzfrequenzmessung zur Bestimmung der Trainingsintensität in Lungensportgruppen.

BACKGROUND: Exercise training is an integral component of the management of patients with asthma and COPD. A training intensity of 60-80% of maximum oxygen uptake (VO(2)max) has been recommended. Instead of ergospirometry measurement of heart rate can be used for training guidance. It is unknown whether the given target can be reached in outpatient training groups with substantial heterogeneity concerning diagnosis, disease severity, and age. METHODS AND PATIENTS: 61 adult patients (m = 15, w = 46; 63 +/- 9 years) with asthma (n = 50) or COPD (n = 11) exercised in groups of ambulant lung sports. An individualized target heart rate was calculated corresponding to an intensity of 60% to 80% of calculated VO(2)max which was equivalent to a heart rate from 97 to 137 beats per minute in the population studied. Heart rate, as a measure of the intensity of charge, was measured continuously with pulse frequency meters. RESULTS: All but one asthma patient exercised in the targeted heart rate range. Patients reached 81 +/- 9% of the training goal of calculated 80% VO(2)max (asthma patients: 79 +/- 9% vs. COPD patients: 88 +/- 9%, p < 0.005) No significant differences regarding training intensities were observed in relation to severity of illness or age. CONCLUSIONS: In outpatient lung sport groups of considerable heterogeneity regarding diagnosis, severity of illness and age, participants reach their individualized heart rate target range. COPD patients were training at a significantly higher relative training intensity. Heart rate is an easy to use parameter for training guidance.

Health-related fitness and trainability in children with cystic fibrosis.

The objective of this study was to examine the effects of a supervised exercise training program performed during an in patient rehabilitation course on various attributes of health-related fitness, e.g., flexibility, balance and coordination. 286 patients with CF, age range 6-18 years (11.8 +/- 3.4 years), mean forced expiratory volume in 1 sec (FEV1 82.7 +/- 22.3% predicted) were included. Patients performed the modified Munich fitness test (mMFT) to assess flexibility, balance, strength and coordination. To assess aerobic capacity a 6-min walk-test (6MWT) was performed. In addition, some of the patients performed an incremental exercise test on a bicycle ergometer using the Godfrey protocol before and after the exercise training program. The supervised training program consisted of 4-6 weeks of different sports activities 5 times per week. After training, pulmonary function showed a significant (P < 0.05) increase. All test items of the mMFT improved significantly (P < 0.05). Compared to healthy children test scores achieved from children with CF in the mMFT were lower but within a normal range. Our children with CF had a lower walk distance in 6MWT (P < 0.05) compared to healthy. Our findings clearly demonstrated benefits of a systematic exercise training program on components of physical fitness in patients with CF, with improvements of test-tasks to predicted normal in some cases. The results from our study suggested that an exercise training program in CF should be focused on several aspects of physical fitness including all components of physical fitness, e.g. aerobic endurance, flexibility, balance and motor skills.

Reliability of verbal descriptors of dyspnea and their relationship with perceived intensity and unpleasantness.

Verbal descriptors of dyspnea have been suggested as being useful in providing information on the underlying pathophysiology. However, little is known about the reliability of these descriptors. The present study examined the reliability of a German language list of respiratory symptom descriptors and studied the association of these descriptors with the intensity and unpleasantness of perceived dyspnea. Fourteen healthy volunteers performed cycle-ergometer exercise and voluntary breath-holding during which they rated the perceived intensity (VAS-I) and unpleasantness (VAS-U) of dyspnea on visual analog scales. Following this, they judged their sensations of dyspnea using the list of symptom descriptors. Both conditions were repeated in reverse order on a subsequent occasion 10 days apart. Ventilatory measures, heart rate, blood lactate, VAS-I and VAS-U during cycle-exercise as well as breath-holding time, VAS-I and VAS-U during breath-holding showed no differences between both occasions. Separate hierarchical cluster analyses identified four clusters of verbal descriptors of dyspnea which were widely comparable between both occasions: effort, speed, obstruction and suffocation. Separate multidimensional scaling analyses (MDS) confirmed these four clusters for each occasion. On both days, perceived unpleasantness of dyspnea was correlated with all four clusters during cycle-exercise, while perceived intensity showed only correlations with effort or speed, respectively. No such correlations were obtained for breath-holding. The results suggest that separable clusters of German language descriptors of dyspnea are reliably used by healthy volunteers. The obtained clusters are widely comparable to previously described clusters in other languages and are differently related to the intensity and unpleasantness of perceived dyspnea.

[Exercise therapy as a therapeutic concept]. / Bewegungstherapie als therapeutisches Prinzip.

Lack of exercise is a primary cause for today's level of morbidity and mortality in the Western world. Thus, exercise as a therapeutic modality has an important role. Beneficial effects of exercise have been extensively documented, specifically in primary and secondary prevention of coronary heart disease (CHD), diabetes mellitus, hypertension, disorders of fat metabolism, heart insufficiency, cancer, etc. A regular (at least 3 x per week) endurance training program of 30-40 min duration at an intensity of 65-70% of VO(2)max involving large muscle groups is recommended. The specific exercise activity can also positively affect individuals with orthopedic disease patterns, i.e., osteoporosis, back pain, postoperative rehabilitation, etc. Endurance strength training in the form of sequential training involving approx. 8-10 different exercises for the most important muscle groups 2 x per week is a suitable exercise therapy. One to three sets with 8-12 repetitions per exercise should be performed until volitional exhaustion of the trained muscle groups among healthy adults and 15-20 repetitions among older and cardiac patients. Apart from a positive effect on the locomotor system, this type of strength training has positive effects on CHD, diabetes mellitus, and cancer.

[Sports injuries and overuse syndromes]. / Verletzungen und Fehlbelastungsfolgen im Sport.

The benefit of regularly performed physical activity as a fundamental component of a healthy lifestyle is uncontradicted. The number of persons who participate in sports in Germany is approximately more than 40 million people, whereof 27.5 million are organised in sport associations. Every year 1.5-2 million sports injuries occur in Germany, which represent 25-30% of all accidents. The costs for treatment amount to a total of 1.5 billion euros. It is estimated that 80% of all sports injuries could be prevented if training and competition were performed correctly. The patterns and risk of injuries differ between particular sport disciplines and are therefore difficult to estimate. Knowledge of specific injury risks is indispensable for prevention of sports injuries. Furthermore this knowledge facilitates both sports physicians' diagnosis and therapy and guidance of the patient. In this review epidemiological data of sport traumatology are surveyed, patterns of injuries of particular sports are described in detail and prevention strategies are given. In a separate section specifics of sports injuries in children are discussed.

[The role of jogging in the prevention and treatment of cardiovascular disease]. / Joggen--Schwimmen--Treppensteigen: So schützt regelmässiges Training Herz und Kreislauf.

Lack of exercise and poor eating habits are considered to be major causes of most diseases of civilization. In consequence, endurance sports, but also an integration of physical activity in everyday life, are gaining in importance. Positive effects of regular physical exercise have been described for CAD, arterial hypertension, lipid metabolic disorders, type 2 diabetes mellitus and the metabolic syndrome. In order to achieve an optimal training effect, exercise intensity should be oriented to the individual anaerobic threshold. As a rule of thumb, 30 minutes of endurance training--ideallyevery day--is considered necessary. Prior testing of a person's ability to undertake such activities should include ECG and blood pressure measurements, spirometry and lactate determination, and contraindications must be taken into account.

[Participation of asthmatic children in gymnastic lessons at school]. / Teilnahme von asthmakranken Kindern am Schulsport - Eine Erhebung an Hamburger Schulen -

INTRODUCTION: Exercise is a predominant stimulus leading to bronchial obstruction in asthmatic children. Therefore physicians, teachers and parents still have a negative attitude towards physical exercise of asthmatic children in school. We investigated the attendance of girls and boys with asthma during sport-lessons at school. METHODS: 254 teachers who give lessons in sports in 46 different schools (high school, primary and secondary school) in Hamburg were asked about their knowledge of the disease and how often and in which manner asthmatic children participated their sport-lessons. RESULTS: Teachers estimated that in each class (average: 25 - 30 children) approximately 1 asthmatic is present. 60 % of these asthmatics take part likewise their healthy peers. 40 % either take part only sometimes (12,6 %) or specific elements (25,2 %) or not at all (12,2 %). Most of the teachers assessed their knowledge about the disease as medium good. In contrast, only 4,7 % of them had a specific plan that allows asthmatics to participate sport-lessons without getting obstructive. CONCLUSION: Asthmatic children are underestimated in school and participate in only 60 % equally to their healthy peers at sport-lessons. The knowledge about this most frequent chronic disease in children could be increased. Better training of teacher-students and teachers is recommended.

[The application of external knee stabilizers - Influence on mechanical stabilization and physical performance]. / Die Anwendung äusserer Kniegelenkstabilisatoren - Einflussnahme auf mechanische Stabilisierung und körperliche Leistungsfähigkeit.

The aim of the study was, to assess the influence of a knee brace on the development of anterior instability after anterior cruciate ligament rupture and to test aptitude for physical strain. 46 subjects with arthroscopically proven anterior cruciate ligament rupture were divided equally in a randomised order into two groups. Both groups carried out a standardized physical therapy program, while one group (0) received additional stabilization by means of a functional knee brace (SofTec, Bauerfeind). In addition, important features of the brace (stabilization capacity, safety perception and physical performance) were tested and compared to the non-braced contralateral leg among 23 healthy physical education students by means of a standardized scaled questionnaire (observational study). 0 showed lower (p < 0.05) development of the anterior instability by 46 % and lower (p < 0.05) reduction in circumference of the femur muscles by 25 %. Increasing the time interval between accident and beginning of the brace treatment, increased the difference of the therapeutical effect of the brace. In the observational study, the brace received a better evaluation regarding all test parameters. The reduction of developing anterior instability by means of a brace should facilitate - apart from an individual operation-time-arrangement - especially a conservative approach within the framework of anterior instability and physical activity. Aside from the improvement of the mechanical stabilization, indications for suitability in strain situations could be detected for the tested brace.

Estimation of an individual equilibrium between lactate production and catabolism during exercise.

During an incremental exercise test after a preceding bout of maximum exercise, blood lactate initially decreases to an individual minimum and then increases again. To determine whether this minimum represents an individual equilibrium between lactate production and catabolism during constant load exercise, the following field tests were performed: in 25 runners and five basketball players (series 1) the speed corresponding to the individual lactate minimum (LM) was measured in test 1 (incremental test after exercise induced lactic acidosis). On two occasions, two constant speed runs over 8 km were performed, one using the LM speed (LMS) (test 2), and another at a running speed of 0.2 m.s-1 above the LMS (test 3). Results of runners/basketball players: blood lactate concentration ([Lac-]B) in test 2 changed from 3.6/4.9 mmol.l-1 to 4.0/4.9 mmol.l-1 during the last 4.8 km, in test 3 from 4.6/4.6 mmol.l-1 to 6.5/6.9 mmol.l-1. These results indicate: 1) the LM speed in test 1 corresponds to a maximum lactate steady state speed during constant load exercise; 2) only a slight speed increase above the LM speed results in continuous marked [Lac-]B increase and earlier exhaustion. Variation of the increment duration in 13 males (series 2) shows no change of the LMS using 800-m and 1200-m increments (4.49 and 4.44 m.s-1) but a marked shift to higher speed using 400-m increments (4.96 m.s-1). Effects of low muscle glycogen stores on the LMS were determined in 10 males (series 3).(ABSTRACT TRUNCATED AT 250 WORDS)

Improved physical performance after treatment of renal anemia with recombinant human erythropoietin.

The physical performance of 12 anemic patients on renal dialysis was investigated following treatment of renal anemia with recombinant human erythropoietin (rhEPO; 40-120 U/kg, 3 times a week). Exercise intensity at a heart rate of 130 beats/min (PWC130) on a bicycle ergometer was assessed before rhEPO treatment, after reaching the target hematocrit (73 +/- 18 days), and in the maintenance phase (211 +/- 53 days). Hemoglobin concentrations measured at these time points were 7.3 +/- 1.2, 11.9 +/- 1.5, and 12.1 +/- 1.4 g/dl, respectively. PWC130 rose from 77 +/- 27 to 104 +/- 37 and 104 +/- 51 W, respectively. Aerobic threshold (i.e. blood lactic acid concentration of 2 mmol/l) shifted to higher workloads indicating improved muscle oxygen supply.

Changes in plasma volume and red cell formation after a marathon competition.

The purpose of this study was to investigate middle-term influences of a marathon race on plasma volume (PV) and red cell production. We performed the following measurements in the blood of 15 male athletes: haemoglobin ([Hb]), haematocrit (Hct), plasma protein concentration ([Prot]), plasma osmolality, sodium concentration ([Na+]), potassium concentration ([K+]), aldosterone concentration ([Aldo]), haptoglobin concentration ([Hpto]), and the reticulocyte count, as well as the calculation of relative changes in PV, 3 days before and on 3-consecutive days after a marathon race. By the 2nd day of recovery PV had increased by 16%. Plasma osmolality and [K+] remained constant, whereas [Na+] had decreased slightly 2 days after the competition and [Aldo] tended to be elevated 1 day after the competition. [Hpto] was low before and 1 day after the competition and increased on the following days. Reticulocyte count was unaffected 1 day after the race, but increased by 106% on the 2nd day and was still elevated after 3 days. The causes for higher post-marathon plasma volumes and reticulocyte counts could be in the complex variations in hormonal regulation, which have not yet been sufficiently investigated.

Hemoglobin oxygen affinity in patients suffering from arterial occlusive disease of the legs.

Parameters characterizing the hemoglobin oxygen affinity were determined in blood of 12 male patients suffering from arterial occlusive disease (AOD) of the legs and compared with data obtained earlier from healthy human subjects (controls). Due to a COHb content of 4.8% +/- 2.2% in the cigarette-smoking AOD patients, the standard oxygen dissociation curve (ODC) was left-shifted, the half-saturation pressure (P50) amounted to 24.8 +/- 1.7 mmHg (3.30 +/- 0.23 kPa), although the 2,3-diphosphoglycerate concentration was increased to 15.3 +/- 1.7 mumol/g Hb. Correcting the effects of elevated COHb shifts the P50 to 26.3 mmHg (3.5 kPa) and increases the steepness of the ODC (Hill's "n") from 2.79 +/- 0.27 to about 2.99, which is significantly different from controls. The Bohr coefficients after acidification of blood with lactic acid (BCLac) show high values at low oxygen saturations of hemoglobin (-0.50 +/- 0.04 in AOD patients, -0.32 +/- 0.04 in controls; P less than 0.05 at 10% SO2). The cause of the alterations in hemoglobin oxygen affinity may be a reduced mean erythrocyte age, but also the influence of unknown factors generated, e.g., from anaerobic muscle metabolism in AOD.