Biomedical subjects

T Horstmann

Publications and source records attributed to T Horstmann.

At least 19 recordsLinked to original sources

PubMed2005

Determining anaerobic capacity using treadmill ergometry.

The determination of anaerobic capacity (AC) using treadmill ergometry is problematic from a methodological, as well as a technical standpoint. In this study, a procedure from Monod and Scherrer was modified to examine whether realistic magnitudes of AC could be determined using three subject groups with different levels of anaerobic training. The subject groups consisted of 10 untrained (UT), 10 aerobic-trained runners (AeT), and 10 anaerobic-trained 400-meter sprinters (AnT). In two separate test series, first the VO2max was determined and second the so-called individual anaerobic threshold (IAT) was used to determine the aerobic power for all subjects. Then all subjects completed a series of sprints with increasing speeds above the VO2max, from which the work output from each test was calculated. Through linear regression, the point of intersection of the regression line with the y-axis was defined as global AC. The results show typically higher VO2max and IAT for AeT (62.2 ml x kg(-1) x min(-1), 14.7 km x h(-1)) compared to UT (53.2 ml x kg(-1) x min(-1); 11.2 km x h(-1)) and AnT (56.7 ml x kg(-1) x min(-1); 11.8 km x h(-1)). AC was significantly higher in AnT (4.1 +/- 0.58 kJ) compared to AeT (1.8 +/- 0.65 kJ) and UT (3.2 +/- 0.68 kJ). The determined absolute values of AC are considerably lower than of comparable examinations using bicycle ergometry. One reason for such an underestimation of AC could be that the horizontal work done during exercise on a treadmill was not taken into enough consideration. Another explanation is that the magnitude of the calculated AC values shows a dependency on the duration of each sprint test. In addition, the critical velocity for all subjects was found to be higher than for IAT, which consequently leads to an underestimation of AC. Moreover, the absolute level of the AC values appears to depend on the endurance of the comparison groups. It can then be concluded that the applied procedure allows for a differentiation amongst a variously trained collective, but does not allow a correct absolute determination of the AC.

Adult↗

PubMed2005

[Sport climbing with adolescents: effect on spine stabilising muscle strength].

Indoor climbing and boulder facilities gain importance in therapy for patients with back pain or with psychic disorders. The effect of climbing on strength of the spine musculature has hardly been investigated in young men and women. To address this question 17 high school students agreed to enrol into a 10-week climbing course twice a week and 9 to serve as controls. All participants were measured before and after training on special devices for measuring the isometric strength of cervical extensors and lateral flexors as well as for thoracic/lumbal spine, the flexors, extensors, the right and left rotators and lateral flexors. The mobility was measured for the transversal and frontal plane. After the climbing course, a gain in strength was measured in all but two muscle groups, the thoracic/lumbal extensors and left lateral flexors, in the control group only for the thoracic/lumbal flexors and left lateral flexors. The gain in strength was higher in the climbing group. The ratio of maximal strength of the right to left rotators was smaller after climbing. Sport climbing in adolescence leads to increased muscle strength of the spine muscles and to an increased muscular balance; thus, for prevention of back pain climbing courses may be introduced in high schools.

Adolescent↗

PubMed2005

[Discomforts and injuries of the spine and medical examinations in young talented female gymnasts].

The distribution of pain and injuries in gymnasts is dependent on the quality of training, but also on sport-medical supervision. In a retrospective analysis 41 female gymnasts aged 11 +/- 2.8 years training 14 h/week filled in a questionnaire on pain and injuries as well as on frequency of sports medical and spine specific examinations. 14 reported partly recurring pain mainly in the lumbar spine and 10 injuries mainly in the cervical spine. Medical treatment needed 6 after recurring pain and 6 after the injuries. Except 3 gymnasts all had been investigated medically at least once, in the mean 1.5 years, after beginning with intensive training. The clinical investigation included an investigation of the spine in 64 % out of which (2/3) received additional x-ray diagnostics. Only among the older participants scoliosis and spondylolisthesis where found twice each. Though no connection between pain or injury was found in relation to previous medical investigation, a thorough clinical and in case of doubt additional radiological investigation of the spine should be performed before intensive training.

Adolescent↗

PubMed2005

Contaminated nutritional supplements--legal protection for elite athletes who tested positive: a case report from Germany.

A significant proportion of nutritional supplements manufactured worldwide contain non-listed contaminations with anabolic-androgenic steroids (AAS), whose ingestion may lead to positive doping test results. This will lead to the suspension of, and sanctions against, the athlete, since this group of active substances is prohibited by the anti-doping code of the World Anti-Doping Agency as well as by sports associations not connected with this agency. Considerable financial losses are often the consequence for a banned athlete. Based on an amendment to the law governing the manufacture and prescription of drugs (AMG) in Germany in 1997 and an increasingly extensive interpretation of the term "drug" by the Federal Supreme Court, preparations containing anabolic steroids or their precursors are to be classified as drugs and, therefore, are subject to compulsory declaration as stated by the AMG. If this obligation is not adhered to, the result may be a claim for damages by the athlete against the manufacturer of a preparation, if the athlete took the preparation thinking it was harmless as judged by the Anti-Doping regulations, but was then found to be positive in doping tests. The judges in the first case before the county court in Stuttgart decided in favour of the claim for damages with respect to lost bonuses, loss of earnings and accrued legal costs by a soccer player who tested positive and was therefore suspended. Based on the evidence presented, the court came to the decision that the soccer player's positive test result was due to the ingestion of nutritional supplements containing non-listed AAS. This procedure could set a precedent for other states to demonstrate that athletes who had tested positive due to contaminated nutritional supplements are not without legal protection.

Anabolic Agents↗

PubMed2002

Exercise-induced, persistent and generalized muscle cramps. A case report.

We are reporting on a 46-year-old man who has suffered of muscle cramps for 4 years, occurring immediately after jogging and playing tennis and lasting for 7-8 hours. Repeated neurological, orthopedic, internal medical and endocrinological examinations showed no pathological findings. Physiotherapy, supplementation of fluids and electrolytes had no effect, nor did medication therapy with muscle relaxants. During spiroergometry without medication, there was an overproportional increase of heart rate and respiratory rate with delayed pCO2 increase after exercise with otherwise normal blood gas levels. This reaction was considerably reduced during spiroergometry under beta-blockade (metoprolol 100 mg); at the same time, the muscle cramps could no longer be induced. Both excessive respiratory regulation and direct hyperadrenergic stimulation should be discussed as the primary cause of the muscle cramps. According to recent findings, b-blockers with intrinsic sympathocomimetic activity should be avoided in therapy.

Adrenergic beta-Antagonists↗

PubMed2001

Gain in strength and muscular balance after balance training.

The isolated effect of balance training on muscle strength of the flexors and extensors of the knee, without accompanying strength training, has not been addressed in the past. Effects of a balance training program alone were compared to a strength training program. Balance and strength training were performed by 15 persons each for 6 weeks including 12 training units of 25 min. Balance training was performed on instability training devices such as rolling board, mini trampoline and large rubber ball. The 15 persons of the strength training group trained on machines for leg curls and on leg presses for 25 min per unit. Measurements for balance were performed with one-leg balance on a narrow edge and a tilting stabilometer for 30 s; maximum isometric strength was measured using an isokinetic device for each leg separately. The muscular balance between dominant and non-dominant leg was calculated. Strength gain was similar for the flexors and extensors in both groups. One-leg balance improved after balance training (P< 0.01) with a 100% increase over the strength training group (P < 0.05) and the stabilometer test for each person in the balance (P < 0.01), but not in the strength training group. In the balance group the initial difference between right and left diminished. The results indicate balance training to be effective for gain in muscular strength, and secondly, in contrast to strength training, equalisation of muscular imbalances may be achieved after balance training.

Adult↗

PubMed2001

Metabolic reaction after concentric and eccentric endurance-exercise of the knee and ankle.

PURPOSE: Power training plays an essential part in many sport disciplines. The importance of eccentric power training remains a matter of controversial discussion. The objective of this study was therefore to investigate the difference in metabolic reaction between eccentric and concentric stress in comparable work. METHODS: Sixty-four men between 22 and 60 yr of age performed maximum isokinetic 1-min endurance tests of the knee and ankle each in concentric (180 degrees.s-1) and eccentric (60 degrees.s-1) modes with comparable total area of contraction-time curve (NS). Higher strength values (mean peak torque, P < 0.01), lower fatigue (fatigue index, P < 0.001), lower increase in lactate (P < 0.01), and lower ammonia production (P < 0.01) were found in eccentric than in concentric exercise, independent of the joint. The eccentric form of stress showed lower decrease and thus age-dependence in maximum strength and in fatigue than the concentric form. RESULTS: The results permit the conclusion that eccentric exercise leads to less fatigue and lower lactate and ammonia reaction than concentric exercise in comparable work levels. Variable visco-elastic properties of the muscle fibers themselves with additive passive strength in eccentric mode is considered as the cause. CONCLUSIONS: It remains uncertain whether the lower metabolic stress might be useful during the training process. A greater scope of training and increased number of training stimuli might be applied in primarily eccentric forms of exercise.

Adaptation, Physiological↗

PubMed2001

Reciprocal strength ratio in shoulder abduction/adduction in sports and daily living.

PURPOSE: Functionally, the shoulder is considered a ball joint, whereby high mobility is attended by low stability. Therefore, muscular balance is decisive for stability. Altered strength ratios are frequently described as "muscular dysbalances" and considered one of the causes of shoulder pathologies, whereby objective quantification is difficult. METHODS: In order to quantify physiological muscle balance, the strength ratio of shoulder abduction/adduction (AB/AD) was determined in 166 untrained men (UM) concentrically at 60 degrees.s-1 (LIDO-Active). The influence on this norm of one-sided (25 high-performance (TPH), 18 leisure tennis players (TPL)) and two-sided athletic exercise (32 gymnasts (GY)), altered daily exercise (11 paraplegics with paralysis time < 4 months (PP), 11 paraplegics with paralysis time > 2 yr (PU)), and a combination of altered daily exercise and athletic activity (16 trained paraplegics (PT)) was examined (ANOVA, alpha = 0.05). RESULTS: Determination of the AB/AD quotient in UM was 0.82. Shoulder stress in sports led to a decrease in quotients compared with UM because of a relatively increased torque in AD (P < 0.01). At the beginning of a paraplegia, the quotient of AB/AD is elevated (P < 0.05). This altered ratio decreases with duration of paralysis (PU) and athletic activity (PT). CONCLUSION: With increased shoulder stress, the altered strength ratios reflect specific requirements of the performance attained. However, the importance of muscular dysbalances for the onset of shoulder complaints must be considered more important than their influence on athletic performance capacity.

Activities of Daily Living↗

PubMed2000

[Individual isokinetic strength training in patients with gonarthrosis].

PROBLEM: To date, therapy of osteoarthritis of the knee is aimed at relieving pain and changing behavior patterns, which usually leads to reduced activity. The weakening of the quadricep's musculature leads to an increase in both joint instability and arthritis. Walking time is prolonged and the pain-induced reaction of knee angle velocity is onset by increased stress on other joints. The progressive muscle atrophy correlates to the degree of pain. The aim of this study was to demonstrate an improvement in strength and pain based on 4-week isokinetic strength training in gonarthritis patients. METHOD: During a conservative hospitalization period, isokinetic strength training was performed by 19 randomized patients with gonarthritis in addition to regular physiotherapy. Another 19 patients functioned as a control group. The work was examined at 60 degrees/s and 180 degrees/s and rated using a pain questionnaire at the start and end of the investigation. RESULTS: In addition to the expected increase of strength and strength endurance in the test group, the degree of pain could also be statistically significantly decreased compared to the control group. Activities of daily living, such as climbing stairs and standing-up, were also performed more easily. CONCLUSIONS: The therapeutic strategy for patients with osteoarthritis of the knee should be reconsidered to include less expensive therapeutic sport measures. Anglo-american and Scandinavian studies support this statement. Overuse and pain can be avoided by precise and low-dose strength training. Objective and reproducible measurements in the patients are essential to make individual training possible.

Adult↗

PubMed2000

In-line skating: injuries and prevention.

BACKGROUND: Most reports on in-line skating injuries describe severe injuries admitted to injury clinics. Little is known about the overall rate of injury and the contribution of the different disciplines. METHODS: In a retrospective inquiry data on injuries were obtained of 105 in-line skaters of whose 69% were active in fitness skating, 59% in jumping/grinding and 51% in the halfpipe. Beside the nature, location and degree of the injury, information was given on where the injury happened and whether protectors were worn at the time of injury. RESULTS: Of 197 injuries 145 healed without medical treatment, 28 needed medical advice once, 22 several times and 2 needed hospitalisation. Injury location were 38% in the upper, 31% in the lower extremities, 21% in the hip/pelvis region and 10% on the head. The most frequent injuries pertained to concussions and skin lesions, 35% each, followed by ligament injuries with 10% and fractures with 5%. Simple injuries were 83% in fitness skating, 70% in jumping/grinding and 60% in the halfpipe. Several visits were necessary for 4% of fitness skaters, 10% of jumpers/grinders and 23% in halfpipe injured persons. All four protectors were worn at the time of injury by 5% in fitness skating, 18% in jumping/grinding and 55% in the halfpipe. No protectors were worn in 26% of the fitness injuries, in 9% jumping/grinding and in 6% in the halfpipe. CONCLUSIONS: The results reveal an apparent discipline specific degree of danger and that fitness in-line skating is less dangerous than the resulting benefits for preventive medicine.

Accidental Falls↗

PubMed1999

Muscular fatigue, maximum strength an stress reactions of the shoulder musculature in paraplegics.

In paraplegic patients, shoulder complaints attributable to muscle dysbalances arising from the particular daily form of exercise are often observed. The goal of therapy is to correct these imbalances through muscular training, whereby eccentric exercise might offer advantages due to lower fatigue with concurrent higher maximum strength. This study therefore examines muscle fatigue, maximum strength, and suitability for paraplegics of eccentric exercise of the shoulder. Muscle fatigue, isokinetic peak torque, and EMG activity were determined eccentric (Ecc) and concentric (Con) in 41 paraplegic subjects (13 early rehabilitants; 16 trained in wheelchair sports; 12 untrained). Serum CK, myoglobin, and subjective pain were collected for one week after exercise. In eccentric exercise, there was less muscle fatigue in all groups. Highest Ecc/Con peak torque ratio was found in trained subjects in all movements, followed by the untrained and the early rehabilitants. EMG-activity was lower in eccentric compared to concentric exercise (Ecc/Con ratio <1). CK and myoglobin concentrations, like pain symptoms, showed a marked increase after exercise. It is concluded that the Ecc/Con strength patterns among paraplegics are altered. Eccentric exercise offers advantages on the basis of lower muscular fatigue independent of training status and lesion time and higher maximum strength with increasing duration of paraplegia and additional athletic training. However, due to structural damage and subjective pain eccentric exercise can only be recommended with reservations in therapy and training.

Adult↗

PubMed1999

Metabolic and cardiocirculatory reactions after concentric and eccentric exercise of the shoulder.

Lower metabolic and cardiocirculatory reactions to eccentric compared to concentric exercise are known for large muscle groups. The extent of exercise reaction depends on the muscle mass involved and moreover differs between the various muscle groups, while it is unclear to which extent cardiovascular and metabolic reactions and differences between the types of work exist in the shoulder, also it is not known whether these reactions differ according to training status. Lactate production (LA), heart rate (HR), and blood pressure (BP) were examined following eccentric and concentric shoulder movements in 16 male gymnasts (GN) and 15 male untrained subjects (US). Differentiation was made according to the types of work for peak torque (PT) and local muscle endurance (LME). Following eccentric exercise, the increase of LA and HR was clearly lower than following concentric exercise (p<0.05). No difference was observed between the groups. Diastolic BP showed no changes, whereas systolic BP was higher following concentric exercise. Eccentric PT was higher than concentric PT in GN within a test-retest variability of 15%. LME showed a lower degree of fatigue under eccentric conditions, independent of the group. It is concluded that eccentric exercise of the shoulder leads to lower metabolic and cardiocirculatory reactions than concentric exercise, in spite of higher peak torque and less fatigue. Exercises consisting of a high proportion of eccentric movement may thus be beneficial in the therapy of shoulder complaints, especially in patients with cardiovascular disease.

Adult↗

PubMed1999

Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility.

Anaerobic threshold as a basic criterion of training recommendation can be estimated by various parameters. The purpose of this study was to investigate the relationship and the reproducibility of ventilatory, lactate-derived and catecholamine thresholds of an incremental treadmill exercise. Therefore, 11 male subjects underwent two incremental treadmill tests within 7 days. The lactate threshold (LT) was determined at the lowest value of the lactate-equivalent (ratio lactate/performance). The individual anaerobic threshold (IAT) was calculated at LT+1.5 mmol/L lactate. The ventilatory thresholds, using mass-spectrometry, were defined by the V-slope method (AT) and at the deflection point of end-tidal CO2 (ET-CO2) concentration (RCP). The thresholds of epinephrine (TE) and norepinephrine (TNE) were calculated in the manner of LT. The running velocities were highly reproducible at LT (test-retest correlation coefficient r=0.90), IAT (r=0.97), AT (r=0.88) and RCP (r=0.95). By contrast TE (r=0.49) and TNE (r=0.46) showed a poor reproducibility. TE and TNE occurred 5-11% below LT and AT with a low correlation to LT and AT. LT was found 4% below AT, both were correlated with r=0.70 (p<0.01, test 1) and r=0.95 (p<0.01, test 2). IAT occurred 7-8% above RCP, in both tests a close correlation was found between IAT and RCP of r=0.97 (p<0.01). In summary, the ventilatory and lactate-derived thresholds show a high and similar reproducibility, but the catecholamine threshold does not. In the present exercise protocol, there are systematic differences between the lactate-derived and ventilatory thresholds, in spite of a close relationship, and these must be taken into account in recommendations derived for training.

Adult↗

PubMed1999

The influence of age on isokinetic torque of the upper and lower leg musculature in sedentary men.

While strength patterns in aging for the knee joint have been well investigated in the concentric mode, few data are available about the behaviour in the eccentric mode and for either modus in the ankle. The purpose of this study was to compile reference data for the lower extremities in untrained men between 20 and 60 years of age to determine the influence of age, especially in the eccentric work mode. Sixty-four male subjects between 20 and 60 years were divided into four age groups. Using a LIDO ACTIVE dynamometer, maximum torque was tested for the knee between 90 degrees to 0 degrees and for the ankle between 30 degrees to -10 degrees at velocities 60, 180, 240, 300 degrees/s concentric, 60 and 120 degrees/s eccentric and isometric with angles 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees for the knee and 30 degrees, 20 degrees, 10 degrees, 0 degrees , -10 degrees for the ankle. Individual parameters for age-dependence were checked using linear correlation calculation with p < 0.01 set as significant. The peak torque (PT) of the knee extensors and flexors showed a typical course with the highest values in the eccentric and isometric mode and a decrease in the concentric mode with increasing angular velocity. In the concentric mode there was a significant negative correlation between PT and age at all angular velocities, but none for isometric and eccentric mode. The greatest maximum torque in the ankle was attained in the eccentric mode at 60 degrees/s. The difference to the knee was smallest in this mode compared to isometric and concentric. The plantar flexion showed age-dependence at all concentric velocities, less in eccentric and none in isometric mode. There was no correlation in dorsiflexion. The influence of loss of muscle fiber and degeneration in the course of aging has thus less influence in eccentric measurements than in the concentric mode. On the contrary, it must be assumed that the high eccentric tensions which are possible due to the quasi-elastic structures in the muscle, are maintained by the increase in stiffness of the connective tissue.

Adult↗

PubMed1999

Bilateral segmental dystonia in a professional tennis player.

Dystonias occur frequently as repetitive movements, persistent elevations of muscle tone, or tonic contortions, whereby the cause is assumed to be an impairment of basal ganglia function. Focal dystonias are especially known in musicians, although little is reported on focal dystonias in athletic stress. The present case report describes the case of a 34-yr-old professional tennis player with bilateral segmental dystonia. The symptoms were expressed in involuntary movements when he intended to hit the ball and in a progredient tremor, initially in one hand, later in both, making him unable to write. The altered mobility during athletic stress was confirmed by video analysis, the altered innervation with excessive, uncoordinated impulse influx by means of electromyography during sport-type specific stress, and writing incapacity during a writing test. The symptoms abated under therapy with trihexyphenidyl-HCL, so that the patient has been able to work as a tennis coach with improved athletic performance for the past 3 yr. It is concluded that the various forms of dystonia should be included in the differential diagnosis of impaired coordinative movements under athletic exercise, especially of the upper extremities.

Adult↗

PubMed1998

[Riding injuries and injuries due to handling horses in experienced riders].

A group of experienced riders who qualified for the German riding badge 9.5 years ago answered a questionnaire pertaining to injuries during jumping, dressage and cross-country riding, as well as handling the horse. During riding 69% of the persons had had 187 injuries and while handling the horse 52% had had 124 injuries. Fractures and contusions were the most-frequent injuries; most riding injuries were located in the upper extremities and shoulder while handling mainly in the hands and feet. The number of injuries was comparable in jumping, dressage or cross-country riding. The time engaged in jumping was about one-third of the other types of riding, but the injuries were more severe. While handling the horse the number of injuries relative to the time spent during the activity were higher but less complicated. No change in safety precautions had been implemented by 67% of the persons injured. The injury rate for equestrians is relatively low both in handling the horse and during riding. The frequent fractures and contusions may be reduced by following the required safety regulations.

Adult↗

PubMed1998

[Traumatology and sports injuries in equestrian acrobatics in the adolescent].

The objective of this study was to compile knowledge of athletic injuries and complaint patterns related specifically to equestrian acrobatics (e.a.). A 20-page standardized questionnaire was sent to 114 e.a. participants. The mean age of the participants in e.a. groups was 15 +/- 3 years, that of independent participants 21 +/- 3 years. A total of 489 injuries was reported, mainly to muscles and tendons (35%), skin (33%) and joints and ligaments (25%). Bone injuries (6%) and head injuries (2%) were infrequent. Analysis of the localization showed that the head-face-neck region was involved in the injury in 3.9%, the torso in 5.5%, the upper extremities in 28%, pelvis and hip region in 3.9%, and the lower extremities in 52%. More than half the injuries were categorized in severity grade I (55%) (not requiring medical attention), 25% were grade II (single medical treatment), 15% grade III (several outpatient medical treatments) and 5% grade IV (requiring hospitalization). Nearly half of the injuries to the lower extremities resulted from jumping exercises, while the cause in upper-extremity injuries was mostly falling (37%). The importance of fall training and limitation of difficulty as well as the number and height of the jumps is discussed. Regular medical examination and improved education of the trainers are demanded.

Accidental Falls↗

PubMed1998

[Quantification of shoulder power in trained and untrained paraplegic wheelchair athletes].

Shoulder complaints are frequently observed to result from the increased stress to the upper extremities of wheelchair users. The cause may be muscle dysbalances of the stressed musculature, whereby the changed situation in the wheelchair during everyday and athletic exercise is important. To demonstrate the different importance of altered shoulder stress in the wheelchair situation and in additional athletic stress, maximum strength in the dominant shoulder was recorded in 14 trained and 13 untrained paraplegics. The goal was to examine the differences between the groups during concentric (60 degrees/s) and eccentric (60 degrees/s) shoulder exercise. Based on the strength/velocity curve, differentiation was also made between the shoulder movements in dependence on various movement velocities. Finally, a comparison was to be made with the test results of untrained and trained, non-paralyzed subjects examined by the same test methods in earlier studies. The results show higher maximum torques in both groups under eccentric stress (p < 0.001), more expressed in trained paraplegics (p < 0.001). In group comparison, there are only slight differences in concentric exercise. The comparison between untrained paraplegics and untrained normal persons (non-paralyzed) show hardly any differences. Trained paraplegics attain values comparable to those of non-paralyzed athletes in eccentric and isometric shoulder exercise. It is concluded, that objective data for determination of the strength situation in the shoulder musculature can be obtained by isokinetic strength measurements in paraplegics. Obviously, eccentric forms of exercise are particularly important. Valuable information can be obtained by determining shoulder strength in dependence on work mode and comparison with non-paralyzed subjects; the information must be interpreted according to the movement.

Adult↗