Biomedical subjects

R Lysens

Publications and source records attributed to R Lysens.

At least 37 records · Page 2Linked to original sources

PubMed1999

Pain-related fear is more disabling than pain itself: evidence on the role of pain-related fear in chronic back pain disability.

There is growing evidence for the idea that in back pain patients, pain-related fear (fear of pain/physical activity/(re)injury) may be more disabling than pain itself. A number of questionnaires have been developed to quantify pain-related fears, including the Fear-Avoidance Beliefs Questionnaire (FABQ), the Tampa Scale for Kinesiophobia (TSK), and the Pain Anxiety Symptoms Scale (PASS). A total of 104 patients, presenting to a rehabilitation center or a comprehensive pain clinic with chronic low back pain were studied in three independent studies aimed at (1) replicating that pain-related fear is more disabling than pain itself (2) investigating the association between pain-related fear and poor behavioral performance and (3) investigating whether pain-related fear measures are better predictors of disability and behavioral performance than measures of general negative affect or general negative pain beliefs (e.g. pain catastrophizing). All three studies showed similar results. Highest correlations were found among the pain-related fear measures and measures of self-reported disability and behavioral performance. Even when controlling for sociodemographics, multiple regression analyses revealed that the subscales of the FABQ and the TSK were superior in predicting self-reported disability and poor behavioral performance. The PASS appeared more strongly associated with pain catastrophizing and negative affect, and was less predictive of pain disability and behavioral performance. Implications for chronic back pain assessment, prevention and treatment are discussed.

Adult↗

PubMed1999

A multidisciplinary approach to the treatment of obesity.

OBJECTIVE: The aim of this paper is: (1) To describe a long-term multidisciplinary group approach to the treatment of morbidly obese persons; and (2) to present, in a preliminary report, results at three months in 30 obese women. DESIGN: Prospective study with evaluation at the start of therapy and after three months of therapy. SUBJECTS: Thirty obese women, initial mean BMI 35.3 kg/m2, age 28-67 y. RESULTS: Body weight decreased significantly (-6 kg) with 74% of weight loss as fat mass. This moderate decrease in body weight resulted in a significant improvement of VO2max/kg body weight. Resting metabolic rate and metabolic parameters remained unchanged. Among psychological variables, participating in the therapy resulted in a more pronounced restrained eating behaviour, an improvement of body image and a higher expression of positive feelings and actions. CONCLUSION: Preliminary results of the program are encouraging. However, continuous evaluation and improvement of the program in the long-term (at least several years) are extremely important.

Adult↗

PubMed1999

Associations between physical activity, nutritional practices and health-related anthropometry in Flemish males: a 5-year follow-up study.

OBJECTIVE: To examine the extent to which extent health-related anthropometric characteristics such as body mass index, waist-hip ratio, waist girth, percentage of body fat and weight gain are associated with physical activity and nutritional habits in a prospective follow-up study. DESIGN: A 5-y prospective follow-up study. SUBJECTS: 132 healthy men from The Leuven Longitudinal Study on Lifestyle, Physical Fitness, and Health. MEASUREMENTS: The main outcome measures in this study were body mass index, waist-hip ratio, waist girth, percentage of body fat and significant weight gain at the ages of 35 and 40y. An unhealthy body composition was defined as a body mass index above 26, a waist-hip ratio above 0.95, a waist girth and body fat percentage above percentile 75 at the end of the 5-y follow-up period and a significant weight gain of 5 kg or more between the two examination periods. Anthropometric characteristics were derived from clinical examination. Physical activity at the age of 35 and 40 and nutritional habits at the age of 40 were determined from questionnaires. RESULTS: Physical activity was the most important predictor for the waist-hip ratio in this sample. In contrast, nutritional habits show a stronger relationship with body mass index. The absolute amount of energy intake is not as important as the dietary factors in predicting subjects with overweight or an unhealthy body composition. The index of occupational activities appears to be the most important physical activity variable. CONCLUSION: The relative contribution of physical activity and nutritional habits in health-related anthropometry varies with the characteristic considered. It is important to include all components of physical activity, and occupational activities in particular, in determining these relationships in a general population sample.

Adipose Tissue↗

PubMed1999

Effects of dilated cardiomyopathy on the diaphragm in the Syrian hamster.

This study aimed to elucidate changes in respiratory muscles and their mechanism in cardiomyopathy. The contractile properties and histology of the diaphragm, as well as serum levels of insulin-like growth factor (IGF)-1, were examined in 10 hamsters with idiopathic dilated cardiomyopathy (CM) and 10 controls. At 28 weeks, body weight in CM was reduced compared with controls (114+/-10 versus 144+/-14 g, p<0.0001). The ratio of diaphragm to body weight was significantly higher in CM than in controls (0.228+/-0.015 versus 0.182+/-0.017, p<0.0001). In vitro, maximal diaphragmatic twitch (303+/-63 versus 455+/-119 g x cm(-2)) and tetanic tensions (1,555+/-369 versus 2,204+/-506 g x cm(-2)) were significantly lower in CM than in controls (p<0.005). The half-relaxation time was significantly shorter in CM (19+/-1 ms) than in controls (24+/-3 ms, p<0.0005). Fatiguability at 25 Hz was significantly less in CM (28%) than in controls (42%, p<0.0001). Diaphragm and gastrocnemius adenosine triphosphatase staining showed type I fibre atrophy in CM, associated with an increase in the number of type I fibres in the diaphragm. Histological examination of both muscles revealed an abnormal muscular pattern. Finally, serum levels of IGF-1 were 47% lower in the CM group than in controls (p<0.0001) and were clearly related to the changes in the contractile properties and histology of the diaphragm. In conclusion, cardiomyopathy in hamsters: 1) depressed the force-generating capacity and shortened the relaxation of the hamster diaphragm; 2) induced type I fibre atrophy in combination with a myopathic pattern; and 3) was associated with a significant reduction in serum levels of insulin-like growth factor-1, related to the diaphragmatic changes. Whether these changes are primary myopathic or secondary to heart failure remains to be elucidated.

Adenosine Triphosphatases↗

PubMed1999

Lumbosacral position sense during pelvic tilting in men and women without low back pain: test development and reliability assessment.

STUDY DESIGN: A single group test-retest design to evaluate the reproducibility of lumbosacral position sense measurements. OBJECTIVES: To develop a measure of position sense in the lumbosacral area and to determine test-retest reliability. BACKGROUND: Proprioception, muscle control, and coordination training could be the key issues in resolving neuromuscular dysfunction in patients with low back pain, but there are no standard ways to assess these parameters. METHODS AND MEASURES: A piezoresistive accelerometer attached to the skin over the sacrum was used to research the repositioning accuracy of active pelvic tilting, between days, of 14 young nonimpaired subjects (20 to 26 years of age) in standing. RESULTS: The mean absolute error for repositioning accuracy (the difference between criterion and matching positions) was 1.81 degrees (+/- 0.85). The intraclass correlation coefficient between measurements obtained on days 1 and 2 was moderate (R = 0.51). The average standard error of measurement associated with the intraclass correlation coefficient was 0.5 degree (95% confidence interval = +/- 0.99 degree). CONCLUSIONS: These findings suggest that the proposed test is sensitive with moderate test-retest reliability to examine lumbosacral position sense in healthy subjects. Further adjustments in the testing protocol are needed to improve the test-retest reliability.

Adult↗

PubMed1998

Incidence of overuse syndromes of the upper limb in young pianists and its correlation with hand size, hypermobility and playing habits.

The incidence of overuse syndromes of the elbow, wrist and hand was evaluated in a series of 66 pianists: 28 presented such a pathology. No significant correlation with starting age, or duration and intensity of practice was revealed. Smaller hands lead to more frequent overuse syndromes, in both males and females. Conditioning, sports activity, playing a second or third instrument, warming-up before playing and stretching afterwards did not influence the incidence of overuse syndromes. Pianists were not more hypermobile than a sex- and age-matched control group, nor was there any significant difference in hypermobility between pianists with and without overuse problems. There was no significant difference in incidence between the left and right side.

Adolescent↗

PubMed1998

Relationship between age-associated endocrine deficiencies and muscle function in elderly women: a cross-sectional study.

OBJECTIVE: Muscle receptors and selected anabolic effects have been identified for both insulin-like growth factor I (IGF-I) and 1,25-dihydroxyvitamin D (1,25(OH)2D3). The aim of the present study was to test the hypothesis that the decreasing concentrations of these endocrine factors might be involved in the decline in muscle function that characterizes normal human ageing. DESIGN: Cross-sectional study. STUDY PARTICIPANTS: A community-based sample of 245 healthy elderly women aged 70-90 years. Exclusion criteria were diseases or medications known to affect muscle function or the somatotrophic axis. MEASUREMENTS: Knee extension strength was evaluated using an isokinetic dynamometer. A standardized questionnaire was used to assess habitual physical activity. IGF-I and 1,25(OH)2D3 were measured by radioimmunoassay. Vitamin D binding protein (DBP) was measured by single radial immunodiffusion and the free 1,25(OH)2D3 concentration calculated as the molar ratio of total 1,25(OH)2D3 to DBP. RESULTS: The differences in isometric and isokinetic strength over the age range were equivalent to losses of 0.9-2.4% per year. However, no relationship was found between the somatotrophic axis or vitamin D status and knee extension strength, despite markedly decreasing concentrations of circulating IGF-I and free 1,25(OH)2D3 with age. CONCLUSION: Levels of circulating IGF-I and free 1,25(OH)2D3 appear not to be involved in the loss of muscle function that characterizes normal human ageing.

Aged↗

PubMed1998

Systolic ventricular dysfunction causes selective diaphragm atrophy in rats.

In order to examine the relative impairment of the diaphragm and other skeletal muscles in systolic ventricular dysfunction (VD), their structure and function were compared between rats with VD induced by left coronary artery ligation (n = 17) and sham-operated rats (Co, n = 10). In addition, in an attempt to unravel the mechanism of the observed impairment, we examined alterations in insulin-like growth factor-I (IGF-I) serum levels and IGF-I expression in the liver, diaphragm, and gastrocnemius. In a second series of rats (VD, n = 5 and Co, n = 5) hemodynamic measurements were performed. All measurements were performed 3 mo after the operation. Infarct size averaged 32 +/- 10 and 44 +/- 20% in the two series, respectively (NS). Hemodynamic measurements revealed a decrease in left ventricular peak systolic pressure of 19% (p < 0. 05). Significant diaphragm atrophy (weight: 622 +/- 52 mg in VD versus 750 +/- 54 mg in Co, p < 0.0005), without alterations in diaphragm contractile properties was present in VD animals. For all animals combined, the reduction in diaphragm weight was related to infarct size (r = -0.74, p < 0.001). No alterations were observed in the other inspiratory and peripheral muscles. ATPase staining of the diaphragm showed atrophy of type I and type IIx/b fibers, their cross-sectional area (CSA) being reduced by 13 and 16%, respectively (p < 0.05). There were no signs of myopathic alterations. IGF-I expression was increased by 55% in the diaphragm of rats with VD (p < 0.05). IGF-I expression in the liver and gastrocnemius and serum IGF-I levels were unaltered. These data suggest the presence of compensatory mechanisms aimed at minimizing diaphragmatic fiber atrophy. We conclude that systolic VD caused: (1) selective diaphragm atrophy, which was related to infarct size; (2) a decrease in diaphragm type I and IIx/b CSA not associated with myopathic changes; (3) an increase in the IGF-I mRNA content of the diaphragm. The selective diaphragm involvement in the present study may be related to the moderate degree of ventricular dysfunction induced.

Adenosine Triphosphatases↗

PubMed1998

Avoidance and confrontation of painful, back-straining movements in chronic back pain patients.

Avoidance of painful activities has been proposed to be an important risk factor for the initiation and maintenance of chronic low back suffering, whereas exposure to these activities has been suggested to be beneficial for recovery. In a cross-sectional study, the differences between chronic patients with avoidant and confrontational styles were investigated using self-report measures and a behavioral test. Participants were first classified as avoiders or confronters. In comparison with confronters, avoiders reported greater frequency and duration of pain, higher fear of pain and injury, more disability in daily living, and more attention to back sensations. Finally, avoiders reported more fear of (re)injury during the behavioral test and had a worse performance than confronters. The results suggest a close link between the fear of pain/(re)injury on one hand and avoidance behavior and physical deconditioning on the other hand.

Activities of Daily Living↗

PubMed1998

Short-term reproducibility of pressure pain thresholds in masticatory muscles measured with a new algometer.

The purpose of this project was to test the within-day and between-days reproducibility of a new and inexpensive algometer. Twelve symptom-free men and nine women participated. Pressure pain thresholds (PPTs) of the bilateral masseter and temporalis muscles were assessed during four sessions (mornings and afternoons of days 1 and 3). During each session, each palpation point of the masticatory muscles was measured four times. There was an interval of only a few seconds between measurements 1 and 2, and between measurements 3 and 4, respectively, while at least 5 minutes of rest were allowed between measurements 2 and 3. The PPT values between the morning and afternoon sessions and between days 1 and 3 were not significantly different. When the within-session reproducibility for all muscles was considered, only the PPT values between measurements 2 and 4 were not significantly different. Analysis of variance showed that the interindividual variability of PPT was 1.4 to 6.8 times higher than the variability observed within or between sessions and days. No gender difference was found.

Adult↗

PubMed1997

Open versus arthroscopic subacromial decompression: analysis of one-year results.

The results of open subacromial decompression (OSD) were compared with arthroscopic subacromial decompression (ASD) after 1 year in 32 subjects (4 bilateral), and the correlation between the two shoulder rating scales for impingement was documented. Patients were evaluated clinically on the modified University of California at Los Angeles (UCLA) shoulder rating scale, and Constant scale. Scapular position and rotation were evaluated as well as a rotation and abduction shoulder strength test using the Cybex II dynamometer. No parameters revealed significant differences between the groups, except for the UCLA score which indicated an advantage for the ASD group (p = 0.046). The OSD group scored 24.5 (5.45) on the UCLA scale and 73.8 (18.9) on the Constant scale, whereas the ASD group scored 28.3 (5.6) and 80.8 (16.4). To study the correlation between both scales, the Pearson correlation product-moment coefficient was calculated and a high correlation (r = 0.81) obtained. Less mobility was found in the operated arm for all parameters, with the exception of glenohumeral abduction in both groups and passive elevation in the OSD group. Only in the OSD group did the scapula in the operated extremity show more abduction of the inferior angle of the scapula. Weaker abduction strength in the operated side was found in the ASD group, whereas in the OSD group there was significantly less adduction and external rotation strength at 180 degrees/s en 240 degrees/s. We conclude that after one year the open group tends to catch up with the arthroscopic patients and that the main benefits after arthroscopic surgery as described in literature are more evident in the shorter period.

Adult↗

PubMed1997

The fate of the oblique abdominal muscles after free TRAM flap surgery.

During recent years, clinical research on the donor site morbidity after free or pedicled transverse rectus abdominis myocutaneous (TRAM) flap surgery has been focusing on the reduced flexion capacity of the abdominal wall. However, the rectus abdominis muscles have close interactions with their synergists and antagonists and collaborate with their neighbouring muscles. The purpose of this study was to examine the consequences of partially resecting the rectus abdominis muscle on the different muscle groups of the abdominal wall. Twenty free TRAM flap patients, 12-61 months (mean 32.1 months) after surgery, were clinically examined, evaluated for curl-up performance and underwent isokinetic dynamometry for flexion, extension and rotation. The patients were compared with 20 non-operated controls. Nineteen patients answered a questionnaire. Abdominal wall abnormalities occurred in 10 patients: umbilical asymmetry (n = 3), abdominal wall asymmetry (n = 4), lower abdominal bulging (n = 2) and hernia (n = 1). Curl-up performance was less in the TRAM flap patients (P = 0.001, Mann-Whitney). Isokinetic flexion, extension and rotation were also less in the TRAM flap patients (Fisher's exact test). This study indicates that what has been believed to be 'limited' surgical damage to the abdominal wall leads to an important reduction in flexion strength but to an even more important reduction of rotation strength due to bilateral displacement and damage of the insertion of the oblique muscles. Partial compensation by synergists is variable and unpredictable on an individual basis. These functional disorders can potentially lead to important changes in activities of daily life.

Abdominal Muscles↗

PubMed1997

The donor site morbidity of free DIEP flaps and free TRAM flaps for breast reconstruction.

This study was undertaken to demonstrate that the deep inferior epigastric perforator (DIEP) flap can provide the well-known advantages of autologous breast reconstruction with lower abdominal tissue while avoiding the abdominal wall complications of the transverse rectus abdominis myocutaneous (TRAM) flap. Eighteen unilateral free DIEP flap breast reconstruction patients were assessed 12-30 months (mean 17.8 months) after surgery. Clinical examination, physical exercises and isokinetic dynamometry were performed preoperatively and two months and one year postoperatively. Intraoperative segmental nerve stimulation, visual evaluation and postoperative CT scans were also used to quantify the damage to the rectus muscle. The 18 patients were then compared with 20 free TRAM flap patients and 20 non-operated controls. Two DIEP flap patients presented with abdominal asymmetry. A limited decrease of trunk flexing strength was noticed but rotatory function was intact. Ten of the TRAM flap patients had umbilical or abdominal asymmetry, bulging or hernias. TRAM flap patients showed a statistically significant reduction in strength to flex and to rotate the upper trunk compared to both the one year postoperative DIEP flap group and the control group. The answers to a questionnaire revealed impairment of activities of daily living for some TRAM flap patients while the activities of all DIEP flap patients were unaffected. Our data demonstrate that the free DIEP flap can limit the surgical damage to the rectus abdominis and oblique muscles to an absolute minimum. We believe it is worthwhile to spend extra operative time, the main disadvantage of this technique, to limit late postoperative weakness of the lower abdominal wall.

Abdominal Muscles↗

PubMed1997

Short-term reproducibility of pressure pain thresholds in masseter and temporalis muscles of symptom-free subjects.

Pressure pain thresholds (PPTs) of the bilateral masseter and temporalis muscles were assessed over a single day and in between 2 days with the aid of an electronic algometer in 11 males and 11 females. Using a mixed model approach, covariance results were controlled for confounding of gender, day, time of the day and the within-session replications of the measurements. For every jaw muscle, the first PPT measurement of a session was markedly higher than the last one of that same session. Except for the right temporalis muscles, no significant systematic PPT differences could be observed between male and female subjects. The differences between morning and afternoon sessions were not significant for any of the muscles tested. Although the PPTs measured on the 1st day were systematically lower than those on the 2nd day for the left masseter and temporalis muscles, no significant difference between the time of the day could be observed when the values of the different muscles were grouped within a subject. Analysis of variance showed that the variability induced by the day or the time of the day was similar to the variability of the measurement itself. The inter-individual variability of PPTs was 2.3 to 9 x higher than the variability observed between trials, sessions or days. The results indicate that the PPT measurement will not be systematically influenced by the time of registration (morning/afternoon) or inbetween consecutive days. In addition, the important inter-individual differences favor the use of longitudinal within-subject studies.

Adult↗

PubMed1996

Measurements of scapular position and rotation: a reliability study.

Smooth motion of the scapula and humerus with respect to the thorax is essential for shoulder function and abnormalities may indicate clinical entities. Recent studies have made an attempt to devise simple, practical means of quantifying scapular position. The aim of this study was to examine the intra-tester and inter-tester reliability of two methods and to determine if significant differences existed between the dominant versus non-dominant extremity. Seventeen healthy volunteers (4 M; 13 F) were examined by two testers. The tape measurements consisted of the classic methods of Kibler and DiVeta in three sitting postures, expanded by the measurement of the linear distance from the medial border to the thoracic mid-line, and the scapular size measure. The SAS software package was used for data analysis. The Intraclass Correlation Coefficient (ICC) intra-tester reliability ranged between 0.96-0.8 for both methods without significant differences, whereas the ICC for inter-tester reliability ranged between 0.42-0.9 with higher values (moderate and good) for the Kibler technique. In the additional tests high values were also obtained for ICC intra-tester, except for the measurements of the linear distance of the medial border of the scapula to the thoracic mid-line and the distance of the inferior process of the acromion to the third vertebra, both in 90 degrees abduction and internal rotation. The ICC for inter-tester was only acceptable for the DiVeta measurement on 45 degrees abduction. Significant differences were noted between both testers on the following measures: Kibler in 45 degrees abduction, DiVeta in 45 degrees abduction and 90 degrees abduction and the scapular size measure. The comparison of dominant versus non-dominant extremity revealed larger but not significantly different means for the dominant extremity in the classic methods. Significant differences occurred for Tester 1 in the measurement of the distance of the medial border to the thoracic mid-line and Tester 2 in DiVita in 45 degrees abduction. The SEM values never exceeded 1 cm. We believe that the Kibler technique holds promise for further studies, has the advantage of measuring in three positions and with some familiarisation can be reliable. Further research is necessary in patients with pathological conditions.

Adult↗

PubMed1996

Inheritance of physical fitness in 10-yr-old twins and their parents.

This study focuses on the quantification of genetic and environmental sources of variation in physical fitness components in 105 10-yr-old twin pairs and their parents. Nine motor tests and six skinfold measures were administered. Motor tests can be divided into those that are performance-related: static strength, explosive strength, running speed, speed of limb movement, and balance; and those that are health-related: trunk strength, functional strength, maximum oxygen uptake, and flexibility. The significance and contribution of genetic and environmental factors to variation in physical fitness were tested with model fitting. Performance-related fitness characteristics were moderately to highly heritable. The heritability estimates were slightly higher for health-related fitness characteristics. For most variables a simple model including genetic and specific environmental factors fitted the observed phenotypic variance well. Common environmental factors explained a significant part of the variation in speed components and flexibility. Assortative mating was significant and positive for speed components, balance, trunk strength, and cardiorespiratory fitness, but negative for adiposity. Static strength, explosive strength, functional strength, and cardiorespiratory fitness showed evidence for reduced genetic transmission or dominance. The hypothesis that performance-related fitness characteristics are more determined by genetic factors than health-related fitness was not supported. At this prepubertal age, genetic factors have the predominant effect on fitness.

Adult↗

PubMed1996

Peripheral and respiratory muscles in chronic heart failure.

It is well-established that in patients with congestive heart failure (CHF), exercise is limited by fatigue and shortness of breath. The poor correlation between the fatigue and indices of central haemodynamic function might indicate that peripheral muscle alterations contribute to impaired exercise capacity. Intrinsic abnormalities of the skeletal muscles have been suggested as a possible explanation. Since the shortness of breath correlates poorly with changes in lung function, changes in the respiratory muscles have been investigated. Studies have demonstrated diaphragmatic myopathy and atrophy similar, in part, to the changes in peripheral skeletal muscles. In CHF, type I (slow twitch) fibre atrophy is seen in respiratory as well as in peripheral muscles. The mechanism of these alterations remains to be elucidated. Studies into the mechanism of muscle dysfunction in congestive heart failure are relevant to the prospect of treatment of the changes in peripheral and respiratory muscles.

Atrophy↗

PubMed1996

Reflex response times of vastus medialis oblique and vastus lateralis in normal subjects and in subjects with patellofemoral pain syndrome.

Various authors have indicated that imbalance of the vastus medialis/vastus lateralis muscles might lead to patellofemoral pain syndrome. However, few reports have been published to substantiate such a hypothesis. The purpose of this study was to attempt to set a scale for the normal reflex response times of the vastus medialis oblique and vastus lateralis muscles after a patellar tendon tap and to determine if patellofemoral pain syndrome patients have an alteration in this firing sequence. A control group of 80 healthy adults was compared with a group of 19 patellofemoral pain syndrome patients. Results indicated that the reflex response time of the vastus medialis oblique was significantly shorter than the reflex response time of the vastus lateralis in the normal subjects (p < or = .01). When comparing these data in the patellofemoral pain syndrome group, a significant earlier firing was obtained from the vastus lateralis in comparison with the vastus medialis oblique (p < or = .01). These findings suggest that a reversal has occurred in the firing pattern of the vastus medialis oblique and vastus lateralis muscles in patellofemoral pain syndrome patients. The results indicate an alteration in the neuromuscular answer of the vastus medialis oblique and vastus lateralis muscles during a patellar tendon tap.

Adolescent↗