Biomedical subjects

L Thorwesten

Publications and source records attributed to L Thorwesten.

At least 19 recordsLinked to original sources

PubMed2004

Muscle strength in patients with unicompartmental arthroplasty.

OBJECTIVE: The aim of the current study was to evaluate the isokinetic strength of the knee in patients with unicondylar prostheses, to compare these results with healthy control subjects of the same age, and to correlate these results with clinical scores. DESIGN: Seventeen patients were examined an average of 21.5 mos after surgery. Clinical examination was done using the Hospital for Special Surgery, Knee Society, and patellar scores and a visual analog scale for pain. Quality of life was assessed by the Short Form 36 Health Questionnaire. Isokinetic evaluation of knee extensor and flexor muscles was done using a Cybex 6000 dynamometer at angular velocities of 60 and 180 degrees/sec. Eleven healthy subjects of comparable age served as a control group. RESULTS: Clinical results differed significantly in all categories. Quality of life differed only in the items of physical functioning, role limitation because of physical problems, and bodily pain. Isokinetic strength in patients showed a loss of torque of approximately 30% in extension and flexion at 60 and 180 degrees/sec compared with the control group. The flexion and extension ratio and the angles of maximum torque did not differ between the groups. CONCLUSION: In comparison with healthy control subjects, persons with an implanted unilateral sledge prosthesis have strength deficits in extension and flexion. A deficit of the extensor muscles, as it has been described previously for patients with a total knee arthroplasty, could not be found.

Aged↗

PubMed2001

Creatine loading and resting skeletal muscle phosphocreatine flux: a saturation-transfer NMR study.

31P saturation-transfer nuclear magnetic resonance spectroscopy was used to study skeletal muscle phosphocreatine (PCr) flux in healthy male volunteers. Data analysis included consideration of effects from incomplete saturation and radiofrequency spillover. Spectra were recorded from the resting gastrocnemius muscle before and after 6 days of creatine monohydrate (Cr-H2O) intake (20 g/day). Parallel to an improved muscle performance during maximal intermittent exercise following Cr-H2O supplementation, the concentration of PCr increased (P=0.01) by 23% (34.9+/-2.8 mmol/l vs. 28.6+/-2.7 mmol/l), whereas other metabolites were unaffected (inorganic phosphate: 4.3+/-1.4 mmol/l, free intracellular Mg(2+): 1.1+/-0.7 mmol/l, cytosolic pH: 7.04+/-0.02). Forward and reverse fluxes through the creatine kinase (CK) reaction did not change significantly from their baseline levels (v(for): 11.8+/-5.4 mmol/l per second vs. 15.3+/-6.8 mmol/l per second, (v(rev): 9.5+/-3.4 mmol/l per second vs. 10.9+/-3.7 mmol/l per second). The rate of PCr resynthesis in resting muscle is not limited by the CK reaction, which is near equilibrium. Consequently, the post-load increase in total creatine has no effect on the unidirectional CK reaction rates.

Adult↗

PubMed2001

[Effect of external stabilization aids of the upper ankle joint on sports-specific performance with reference to isokinetic strength measurements].

Two questions were investigated: Do ankle devices have any influence on sports performance? Are there any differences between the devices? 31 participants could be included. The average age was 24.5 (+/- 4.1). The participants exercised 5.8 hours/week. We tested 41 ankles without any previous injury. With the Cybex 6000 four parameters were evaluated. Torque maximum for the plantarflexion, range of motion, work in Joule. The ankles were tested with three different ortheses, ankle taping and without any device. The Friedman Test was used to evaluate differences between the five test conditions. All measurements showed significant worse results for the devices and taping. The protective effect of ankle devices is well known. In this investigation we could show a restriction of the performance. Thus it should be decided individually, if an ankle device is useful.

Adult↗

PubMed2001

Decoupling of intracellular calcium signaling in granulocytes after exhaustive exercise.

There is growing evidence that exhaustive exercise can induce a suppression of the innate immune functions. Most studies so far describe exercise induced changes in cell counts or functional responses while information regarding intracellular signal transduction parameters is lacking. Therefore in the present study we investigated in granulocytes the regulation of intracellular calcium ([Ca2+]i) which is an important intracellular second messenger. Healthy volunteers underwent a treadmill exercise test at 80% of their maximal oxygen uptake until exhaustion. Granulocytes were separated before and 1 hour after the test. [Ca2+]i was analyzed spectrophotometrically using the Ca2+ sensitive fluorescent dye Fura-2, while the oxidative burst and phagocytosis were measured by flow cytometry. While resting [Ca2+]i levels were unchanged, the Ca2+ transient induced N-formyl-methionyl-leucyl phenylalanine (fMLP) and platelet activating factor (PAF) were enhanced 1 hour after the test compared to pre-exercise values although fMLP receptor density did not change. In contrast, oxidative burst and phagocytosis evoked by fMLP and phorbol-myristate-acetate (PMA) were decreased after exercise. Together, our data support the view that exhaustive exercise affects regulation of Ca2+ signaling in granulocytes. The potentiation of Ca2+ signals is not accompanied by an enhancement of cellular functional parameters suggesting a blockade in intracellular signalling pathways.

Adult↗

PubMed2001

Alterations in intracellular calcium signaling of lymphocytes after exhaustive exercise.

PURPOSE: Exhaustive exercise is accompanied by pronounced quantitative changes in leukocytes. Whereas most studies on lymphocytes have concentrated on their proliferative responses or cytokine secretion, not much is known about exercise-induced changes in intracellular signal transduction processes. In lymphocytes, the concentration of intracellular free calcium ([Ca(2+)](i)) is an important intracellular second messenger linking extracellular stimuli to cellular responses. The aim of the present study was to examine the effect of exhaustive exercise on the calcium homeostasis of lymphocytes. METHODS: Healthy volunteers underwent treadmill exercise at 80% of their maximal oxygen uptake until exhaustion. Blood samples were taken before, immediately after, 1 h after, and 1 d after the test. Lymphocyte subsets were analyzed by flow cytometry; isolation of lymphocytes was performed by density gradient centrifugation. [Ca(2+)](i) was measured using the calcium-sensitive fluorescent dye Fura-2. RESULTS: Compared with preexercise conditions, basal [Ca(2+)](i) was increased immediately after exercise, whereas there was no change after 1 h or 1 d. The anti-CD3- and phytohemagglutinin-induced Ca(2+) responses demonstrated a bivalent pattern. Immediately after exercise, Ca(2+) transients were impaired, whereas 1 h after and 1 d after the test, the Ca(2+) responses were increased. In contrast, the Ca(2+) responses induced by thapsigargin were not different at any time interval. Lymphocyte subsets increased immediately after exercise, especially natural killer cells and CD8+ T cells, and decreased below preexercise levels after 1 h. One day after exercise, cell counts were not different from preexercise levels. CONCLUSIONS: Taken together, this novel approach demonstrates that exhaustive exercise has a profound influence on intracellular calcium signaling of lymphocytes. These effects may explain changes in lymphocyte function that have previously been reported.

Adult↗

PubMed2000

Interdependence of clinical and isokinetic results after bicondylar knee prostheses with special emphasis on quality of life results.

Nineteen patients were examined at an average follow-up of 2 years after total knee joint replacement without patella resurfacing. They were compared with 22 healthy subjects of the same age. Using the Hospital for Special Surgery (HSS) score the operated knee joints scored an average of 77 points, the contralateral side scored 87 points and the control group 97 points. In the SF-36 health questionnaire the patients showed highly significant deviations. Isokinetic measurements revealed a clear loss of isokinetic strength of more than 50% on average in flexion as in extension when compared to the control group and there were considerable asymmetries between the operated and the contralateral legs.

Aged↗

PubMed1998

Injury pattern and acceptance of passive and active injury prophylaxis for inline skating.

In a field study the injury pattern as well as the active and passive injury prophylaxis of 1036 inline skaters were evaluated. Of them, 60% had already been injured. Every 124 h an injury occurred during inline skating. While 61% of the injuries affected only soft tissue, 31% were joint distorsions, and 8% were fractures. Altogether 37% of the 626 injured skaters required medical treatment. The upper extremities are especially at risk: 78% of the fractures and 48% of the distorsions affected the fingers, wrist, forearm or elbow. It is obvious that the inline skaters' passive prophylaxis measures are still unsatisfactory. Only 17% of the questioned used complete protection, whereas 16% were wearing no protective gear at all. Of the rest, 49% were skating with wrist guards, 66% were using knee pads, and 31% elbow pads. A high percentage of injuries is due to the lack of basic knowledge and techniques. The survey revealed that only 24% can stop immediately. While 51% had only slight problems with braking, 16% admitted having great difficulties, and 7% were not able to brake at all. These numbers reveal that there are still large deficits regarding braking techniques and education on the risks of injury. Therefore, athletes who use this equipment for the first time should learn the basic techniques of skating, braking and falling with the help of a qualified instructor. Most of all those questioned wanted to have more information, and half would be interested in special educational programmes.

Adolescent↗

PubMed1998

[The influence of knee bandages on sport specific capabilities in healthy volunteers and patients with rupture of the anterior cruciate ligament].

In 15 male healthy volunteers and 10 male patients with ACL-deficiency sports specific capabilities were evaluated with a 9-3-6-3-9-run and a single-leg jumping test. Each subject was tested with and without different knee bandages. We evaluated the Patelladyn-, the Kasseler-, the Super-Genuplus-, and the Genuhit-bandage. Additionally a subjective assessment of each bandage was performed by the volunteers. There were no significant difference performing the 9-3-6-3-9-run between all of the bandages in the control-group. Comparing the injured group with the control there were significant differences. All bandages led to improvement without reaching the running time, which was used by the controls. Performing the single leg jumping test there were also no differences with the different bandages in the healthy control group. However, after applying a bandage in the injured subjects, the time improved significantly. In the subjective assessment the Patelladyn-bandage scored best.

Adolescent↗

PubMed1998

[Joint stress in inline skating--a biomechanical study].

UNLABELLED: In 8 male subjects we undertook acceleration measurements under standardised conditions at the tibia, the hip and the head. The measurements were performed on a normal flat street as well as on a bicycle route with velocities of 15 km/h, 20 km/h and 25 km/h. Additionally we documented the range of motion at the knee joint. Maximal positive acceleration at the head sensor was 10.75 m/s2 at a velocity of 25 km/h on the bicycle route. At the hip the highest measured value was documented with 15.10 m/s2 at 25 km/h also on the bicycle route. Die maximal tibia acceleration was 55.8 m/s2 at 25 km/h again on the bicycle surface. The amplitude averaged signals showed the highest suppression between tibia and hip. CONCLUSION: Compared to other athletic activities acceleration and joint load in in line-skating is only low.

Acceleration↗

PubMed1998

[Incidence of injuries in parachuting].

During the German championships in parachuting 78 paratroopers were asked about acute injuries and chronic pain using a questionnaire. A total amount of 131 injuries was described. These were evaluated in terms of dimension and localisation. Upper and lower parts of the body were injured with a comparable frequency. Bruises (42%), fractures (19%), sprainings (16%) and dislocations (10%) were most often described. The overall injury rate according to the total number of descents (0.09%) was lower than that reported by previous literature. Therefore it can be concluded that parachuting for experienced jumpers is less dangerous than assumed until today.

Adult↗

PubMed1998

[Long-term effects of ankle joint orthoses on sports specific capability in handball].

UNLABELLED: We documented the effect on sports specific capabilities of long lasting wear of ankle braces in 14 handball players. For a period of 4 months half of the team performed all athletic activities with an ankle brace. The other players served as control performing the same athletic activities without wearing a brace. For documentation of the coordinative capabilities a special jump-test with a COMET-system was used. This test was performed after a standardised warm-up at the beginning and at the end of the 4 months observation period with and without an ankle brace. The results showed that wearing the used ankle brace for a period of 4 months did not lead to a negative effect on jumping capabilities. The brace group showed even an increased ability in the used test. This could be documented in short as well as long term effects. CONCLUSION: Long wear of ankle braces do not lead to negative side-effects in sports specific capabilities that are represented by the performed jump-test.

Adult↗

PubMed1998

[Effects of a proprioceptive training program on sensorimotor capacities of the lower extremity in patients with anterior cruciate ligament instability].

Sensomotory function after ACL-reconstruction was tested prior and after a proprioceptive rehabilitation program with the Kinesthetic Ability Trainer (KAT 2000) which documented the static balance index (SBI). A control group consisting of healthy subjects was also tested two times with a time interval of six weeks. The results showed an adaptation effect to the testing device in the control group with an 17.12% increase of the SBI. There were no differences between the dominant and non dominant extremity. The active sensomotory function in the healthy knee of the operated patients showed no difference to the control group. Proprioceptive capabilities of the acl-reconstructed knee joints was significant reduced 6.42 weeks after surgery. A special proprioceptive rehabilitation program for six weeks significantly reduced this deficit. In the patient group sensomotory function of both knee joints could be increased to a level higher than in the control group. In the operated extremity the static balance index increased 27.75% and in the non injured extremity the SBI increased 16.88%.

Adult↗

PubMed1997

[Automobile head supports--adjustment possibilities and utilization. Results of a field study].

An important detail referring to the whiplash syndrome is the relationship between the position of the head restraint and the head, because the head restraint protects the head in case of a rear-end accident. This relationship was evaluated in a representative study in 601 nonselected volunteers. A horizontal distance between the head and head restraint of maximal 9 cm was present in 69.6%. An optimal distance of 0 cm was only found in 7.4%. Just 50% of the adjustment distance was used by the car drivers. Even in completely distracted adjustments in 50% a deficit of more than 8 cm, and in 20.9% a deficit of even more than 12 cm was present. These results show that passive protection, on the one hand, is not guaranteed because of the lack of proper height adjustment. On the other, the volunteers did not use the best adjustment each time.

Accidents, Traffic↗

PubMed1997

Influence of external stabilizing devices of the ankle on sport-specific capabilities.

We compared sport-specific-skills in 23 athletes with functionally unstable ankle joints to those of 18 healthy volunteers by performing a Japan test as well as a specially designed single-leg jumping test. For external stabilization of the ankle, an Aircast brace, a Ligafix Air brace, a Malleoloc brace and a tape bandage were applied. For the Japan test in the group with uninjured ankle joints, the best results were obtained when wearing the Aircast brace, followed by tape bandage, Ligafix brace and no stabilizing device in descending order. The worst results were presented by the group with the Malleoloc brace. However, there were no significant differences among these devices. In the group with functionally unstable ankle joints, the best score was achieved with the tape bandage, followed by the Ligafix brace, Mallcoloc brace and Aircast brace. The unstabilized group showed significantly worse results compared with all other groups. In the single-leg jumping test, the stabilizing devices had no negative influence on the jumping capability in the uninjured ankle joints. Additionally, there was no significant difference among the orthoses. Volunteers with unstable ankle joints experienced a significant improvement of jumping performance with most of the devices. The best results were achieved with the Aircast brace, followed by the Malleoloc brace, Ligafix brace and tape bandage. However, there was no significant difference among these orthoses. While the reaction time of the volunteers was the same for all test situations, the time for dynamically stabilizing the ankle joint appeared to be significantly worse in those ankle joints without a brace. For athletic activities, which are dominated by movement patterns comparable to the Japan test as well as the jumping test used, these stabilizing devices seem to have no negative effect on sport-specific capabilities.

Adult↗

PubMed1997

[Proprioception of the shoulder joint in young tennis players].

In 60 adolescent volunteers aged 8 to 16 years we assessed the proprioceptive capability of the shoulder complex by an angle reproduction test. The purpose of the study was to evaluate the proprioceptive capability of adolescent tennis players. 40 were tennis players, 20 non tennis players served as a control group. Documentation of the reproduced angle was performed by a motion analyzing system with passive markers. Angle reproduction of all volunteers was best in the midrange of motion (100 degrees flexion, 100 degrees abduction, neutral rotation in 90 degrees abduction). The worst results were documented below shoulder level (50 degrees flexion, 50 degrees abduction, internal rotation in 90 degrees abduction). A correlation to sex or dominant extremity could not be found. Subjects older than 12 years showed a tendency for better angle reproduction compared to the younger subjects. Tennis players older than 12 years demonstrated significant better capabilities for angle reproduction in some movements of the shoulder complex.

Adolescent↗

PubMed1997

[Effect of external stabilizing agents of the ankle joint on sports motor capacities in one legged jumping].

UNLABELLED: In order to document sport specific skills, 23 athletes with functionally unstable ankle joints as well as 18 healthy volunteers were evaluated by performing a single leg jumping test. For external stabilization of the ankle an Aircast-Brace, a Ligafix-Air-Brace, a Malleoloc-Brace as well as a tape bandage were applied. There was no negative influence on the jumping performance of the tested stabilizing devices in the uninjured ankle joints. There was also no significant difference between the devices. For functional unstable ankle joints most of the devices showed significant improvement of jumping performance. The best results were achieved by the Aircast-Brace, followed by the Malleoloc-Brace, the Ligafix-Brace and the tape bandage. Again, there was no significant difference between these devices. While the reaction time showed no difference in all test situations, the time for stabilizing the ankle joint was significantly worse in those ankle joints without a brace. CLINICAL RELEVANCE: For athletic activities, which are dominated by movement patterns comparable to the applied jumping test, the tested stabilizing devices seem to have no negative effect on sports specific capabilities.

Adult↗

PubMed1997

[Pronation angle of the rear foot during running in relation to load].

In 20 volunteers the relationship between rear-foot pronation and increasing physical exertion during treadmill ergometry was examined. In order to assess the influence of regularly performed running training a group of 10 endurance trained middle- and long-distance runners (age: 27.4 +/- 4.9 years; weight: 71.0 +/- 8.8 kg; height: 184.2 +/- 8.3 cm) was compared to another group of 10 untrained subjects (age: 24.7 +/- 2.1 years; weight: 73.3 +/- 9.8 kg; height: 179.1 +/- 8.3 cm). The examinations were carried out on a treadmill using a high-frequency motion analyzing system. Heart rate, blood lactate as well as rear-foot pronation were measured. Regarding heart rate and lactate concentration there were significant differences between trained and untrained volunteers. The pronation angle increased with higher speed up to a maximum of 6.54 +/- 4.22 degree for the trained group and 6.84 +/- 4.59 degree for the untrained group. With reference to maximal as well as submaximal stages the pronation angles showed no significant differences between both groups. Following the maximal exercise level the runners performed an additional 3 min run with a velocity reduced by 8 km/h compared to the maximal speed. At this level the total group as well as the untrained group showed significantly greater pronation angles compared to those of the corresponding velocity at the beginning of the test. The extent of the differences, however, was not significantly correlated with the lactate levels. Our results demonstrate that the increase of the pronation angle is a function of the running speed. But there is also an influence of fatigue, which depends neither on the running velocity nor on the lactate levels during exercise. Therefore, further investigations should emphasize the question which factors are responsible for this effect.

Adult↗

PubMed1996

Proprioceptive function of the shoulder girdle in healthy volunteers.

In 27 healthy volunteers (9 females, 18 males) we evaluated the proprioceptive function of the glenohumeral joint. The volunteers were asked to place the arm in different positions with and without visual control. The test was performed for the dominant and for the nondominant extremity. The following joint positions were measured: 50 degrees, 100 degrees, 150 degrees abduction; 50 degrees, 100 degrees, 150 degrees flexion; +45 degrees, 0 degrees, -45 degrees rotation in 90 degrees abduction. Joint position was documented with a motion-analyzing system with passive reflecting markers. The results showed significant differences between the measurements with and without visual control. Proprioception was worse below the shoulder level (50 degrees abduction, flexion). Two volunteers with generally good coordinative capabilities showed better results than the rest of the group. We observed no differences between dominant and nondominant extremities nor between males and females. Our results demonstrated low variance of the proprioceptive function of the glenohumeral joint in healthy volunteers. Our findings serve as a base for further evaluations in different patients' populations.

Adult↗