Association between bone, body composition and strength in premenarcheal girls and postmenopausal women.

AIM: The study examined whether associations between bone, body composition and strength are age dependent. SUBJECTS AND METHODS: Two age levels (premenarcheal girls and postmenopausal women on HRT) were studied in a 10-month follow-up. Bone, lean and fat mass were measured by dual-energy X-ray absorptiometry (DXA), and strength was measured using an isokinetic dynamometer. RESULTS: In girls, significant correlations were found between mass (lean, fat and body mass), strength and most bone characteristics (r = 0.15-0.93). At the proximal femur changes in bone mineral density (BMD) were moderately related to changes in body composition. In the women, body mass and lean mass were significantly correlated with most bone characteristics (r = 0.34-0.82). Low to moderate correlations were observed between changes in bone and changes in body composition. After controlling for lean mass the relation between strength and bone was no longer significant. CONCLUSIONS: In premenarcheal girls, bone is partly determined by mass, with lean mass the most important predictor at the femoral sites. In postmenopausal women, lean mass is an important determinant of bone mineral content (BMC) and BMD, but changes in BMD are related to changes in fat. The relation between strength and BMD is mainly attributable to the relation between lean mass and BMD. The contributory effects of soft tissue to bone change over different life periods.

Heritability of somatotype components from early adolescence into young adulthood: a multivariate analysis on a longitudinal twin study.

BACKGROUND: Several studies with different designs have attempted to estimate the heritability of somatotype components. However they often ignore the covariation between the three components as well as possible sex and age effects. Shared environmental factors are not always controlled for. AIM: This study explores the pattern of genetic and environmental determination of the variation in Heath-Carter somatotype components from early adolescence into young adulthood. SUBJECTS AND METHODS: Data from the Leuven Longitudinal Twin Study, a longitudinal sample of Belgian same-aged twins followed from 10 to 18 years (n = 105 pairs, equally divided over five zygosity groups), is entered into a multivariate path analysis. Thus the covariation between the somatotype components is taken into account, gender heterogeneity can be tested, common environmental influences can be distinguished from genetic effects and age effects are controlled for. RESULTS: Heritability estimates from 10 to 18 years range from 0.21 to 0.88, 0.46 to 0.76 and 0.16 to 0.73 for endomorphy, mesomorphy and ectomorphy in boys. In girls, heritability estimates range from 0.76 to 0.89, 0.36 to 0.57 and 0.57 to 0.76 for the respective somatotype components. Sex differences are significant from 14 years onwards. More than half of the variance in all somatotype components for both sexes at all time points is explained by factors the three components have in common. CONCLUSIONS: The finding of substantial genetic influence on the variability of somatotype components is further supported. The need to consider somatotype as a whole is stressed as well as the need for sex- and perhaps age-specific analyses. Further multivariate analyses are needed to confirm the present findings.

Predictors of 6-minute walk test results in lean, obese and morbidly obese women.

The aim of this study was first, to assess the presence of medical conditions that might interfere with walking; second, to assess the differences in walking capacity, perceived exertion and physical complaints between lean, obese and morbidly obese women; and third, to identify anthropometric, physical fitness and physical activity variables that contribute to the variability in the distance achieved during a 6-minute walk test in lean and obese women. A total of 85 overweight and obese females (18-65 years, body mass index (BMI) > or = 27.5 kg m(-2)), 133 morbidly obese females (BMI > or = 35 kg m-2) and 82 age-matched sedentary lean female volunteers (BMI < or = 26 kg m(-2)) were recruited. Patients suffering from severe musculoskeletal and cardiopulmonary disease were excluded from the study. Prior to the test, conditions that might interfere with walking and hours of TV watching were asked for. Physical activity pattern was assessed using the Baecke questionnaire. Weight, height, body composition (bioelectrical impedance method), isokinetic concentric quadriceps strength (Cybex) and peak oxygen uptake (peakVO2_bicycle ergometer) were measured. A 6-minute walk test was performed and heart rate, walking distance, Borg rating scale of perceived exertion (RPE) and physical complaints at the end of the test were recorded. In obese and particularly in morbidly obese women suffering from skin friction, urinary stress incontinence, varicose veins, foot static problems and pain, wearing insoles, suffering from knee pain, low back pain or hip arthritis were significantly more prevalent than in lean women (P < 0.05). Morbidly obese women (BMI > 35 kg m(-2)N = 133) walked significantly slower (5.4 km h(-1)) than obese (5.9 km h(-1)) and lean women (7.2 km h(-1), P < 0.05), were more exerted (RPE 13.3, 12.8 and 12.4, respectively, P < 0.05) and complained more frequently of dyspnea (9.1%, 4.7% and 0% resp., P < 0.05) and musculoskeletal pain (34.9%, 17.7% and 11.4% resp., P < 0.05) at the end of the walk. In a multiple regression analysis, 75% of the variance in walking distance could be explained by BMI, peakVO2, quadriceps muscle strength age, and hours TV watching or sports participation. These data suggest that in contrast with lean women, walking ability of obese women is hampered not only by overweight, reduced aerobic capacity and a sedentary life style, but also by perceived discomfort and pain. Advice or programs aimed at increasing walking for exercise also need to address the conditions that interfere with walking, as well as perceived symptoms and walking difficulties in order to improve participation and compliance.

Health-related quality of life in physically active and sedentary obese women.

The aim was to assess dimensions of health-related quality of life (HRQL) in women attending an obesity clinic, and to rate differences in HRQL in those with the highest and lowest levels of physical activity (PA). The sample included 113 sedentary and 101 physically active subjects from a total sample of 375 overweight women 16-65 years, with a body mass index (BMI) > or =27.5 kg/m(2) consulting at an outpatient Endocrinology Clinic, and 82 lean female volunteers who served as a reference. Weight, height, body composition, PA, physical medical conditions, depression, body image, cognitive-behavioral conceptualization of obesity, eating behavior, functional status, walking ability, exercise capacity, social functioning, and general health and perceived quality of life were assessed cross-sectionally. The prevalence of medical conditions and depression was not statistically different (P < 0.05) in sedentary and active women. In sedentary obese women, body attitude, walking ability, and aerobic fitness were poorer; the number of people to turn to for social support was smaller; physical attributions about the basis of the subjects obesity were less pronounced; and eating was more the consequence of external triggers or diffuse emotions than in physically active obese women (P < 0.05). The findings indicate that a higher level of PA in an obese female clinical population was positively associated with diverse dimensions of HRQL. However, it was not possible to determine if these favorable aspects of HRQL are the cause or the consequence of a higher PA level.

Orthotic devices for treating patellofemoral pain syndrome.

BACKGROUND: Patellofemoral pain syndrome is a frequently reported condition in active adults. A wide variety of conservative treatment strategies have been described. As yet, no optimal strategy has been identified. Application of orthotic devices e.g. knee braces, knee straps, forms of taping of the knee, active training devices, knee sleeves and in-shoe orthotics to support the foot have been advocated to treat this condition. OBJECTIVES: To assess the effectiveness of foot and knee orthotics for treatment of patellofemoral pain syndrome. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group specialised register (December 2001), the Cochrane Controlled Trials register (Issue 2, 2000), MEDLINE (January 1966 to March 2000; EMBASE (January 1988 to March 2000); CINAHL (January 1982 to March 2000) and PEDro (up to March 2000). Relevant orthotic companies were contacted. SELECTION CRITERIA: All randomised and quasi-randomised trials comparing the effectiveness of knee or foot orthotics for treatment of patellofemoral pain syndrome were selected. Trials describing the use of orthotic devices in conjunction with operative treatment were excluded. DATA COLLECTION AND ANALYSIS: Three reviewers independently assessed methodological quality of the identified trials by use of a modified version of the Cochrane Musculoskeletal Injuries Group assessment tool, consisting 11 items. Two reviewers extracted data without blinding. Trialists were contacted to obtain missing data. MAIN RESULTS: Five trials involving 362 participants were included in this review. Five other trials await possible inclusion if further information can be obtained and one awaits further assessment. Due to clinical heterogeneity, we refrained from statistical pooling and conducted analysis by grading the strength of scientific evidence. The level of obtained research-based evidence was graded as limited as all trials were of low methodological quality. This limited research-based evidence showed the Protonics orthosis at six week follow-up was significantly more effective for decrease in pain (weighted mean difference (WMD) between groups 3.2; 95% confidence interval (CI) 2.8 to 3.6), functional improvement on the Kujala score (WMD 45.6; 95% CI 43.4 to 47.7) and change in patellofemoral congruence angle (WMD 17.2; 95% CI 14.1 to 20.3) when compared to no treatment. A comprehensive programme including tape application was significantly superior to a monitored exercise programme without tape application for decrease in worst pain (WMD 1.6; 95% CI 0.4 to 2.8) and usual pain (WMD 1.2; 95% CI 0.2 to 2.1), and clinical change and functional improvement questionnaire scores (WMD 10, 95% CI 2.07 to 17.93) at four weeks follow-up. The trials reported statistically significant differences in patient satisfaction after applied therapy (WMD 3.3; 95% CI 0.5 to 6.1) in favour of the McConnell regimen compared with the Coumans bandage at six weeks follow-up. REVIEWER'S CONCLUSIONS: The evidence from randomised controlled trials is currently too limited to draw definitive conclusions about the use of knee and foot orthotics for the treatment of patellofemoral pain. Future high quality trials in this field are warranted.

Which factors predict outcome in the treatment program of anterior knee pain?

The goal of this prospective study was to determine the outcome-predictive role of various parameters in the nonoperative treatment of chronic anterior knee pain patients. Thirty patients followed a five-week treatment program, which consisted out of only closed kinetic chain exercises. Prior to this treatment all subjects were evaluated on muscular characteristics, subjective symptoms, weight, sex, duration of symptoms and functional performance. A multiple stepwise regression analysis revealed that the reflex response time of m. vastus medialis obliquus (VMO) (P=0.041; 0.026), and the duration of symptoms (P=0.019; 0.045) were the only two parameters which were significantly associated with the outcome (evaluated by the Kujala score) at five weeks, and at three months. The shorter the duration of symptoms, or the faster the reflex response time of VMO prior to the treatment, the better the outcome after a closed kinetic chain exercise program. The statistical significance of these parameters in this study may be seen as an indication of the importance of these variables as predictors of the outcome of a closed kinetic chain strengthening program. Using this information, it seems clinically important to begin the treatment program before the anterior knee pain becomes more chronic and treatment results become less good.

Relation between cardiovascular risk factors at adult age, and physical activity during youth and adulthood: the Leuven Longitudinal Study on Lifestyle, Fitness and Health.

This study investigated the relationship between sports participation/physical activity during youth (13 - 18 years of age) and adulthood (30 - 40 years of age), and cardiovascular risk factors (body fat and fat distribution, blood pressure, lipoprotein levels and cardiorespiratory fitness) at 40 years of age. Subjects were 166 Flemish males from "The Leuven Longitudinal Study on Lifestyle, Fitness and Health". Physical activity was assessed by means of a sports participation inventory and the Tecumseh community Health Study Questionnaire. In addition to correlation and multiple stepwise regression analyses, different groups (at risk, not at risk) were contrasted on sports participation/physical activity parameters using ANOVA. Long-term exposure during adulthood to daily physical activity was slightly related to a low/high risk profile for waist circumference, percent body fatness, triglycerides and peak VO(2). Sports participation during adolescence was not related to levels of cardiovascular risk factors at 40 years of age.

Exercise capacity in lean versus obese women.

The aim of this study was to assess the nature and magnitude of the differences in submaximal and maximal exercise capacity parameters between lean and obese women. A total of 225 healthy obese women 18-65 years (BMI> or=30 kg/m(2)) and 81 non-athletic lean women (BMI< or=26 kg/m(2)) were selected. Anthropometric measurements (weight and height), body composition assessment (bioelectrical impedance method) and a maximal exercise capacity test on a bicycle ergometer were performed. Oxygen uptake (VO(2)), carbon dioxide production (VCO(2)), expired ventilation (VE), respiratory quotient (RQ), breathing efficiency (VE/VO(2)), mechanical efficiency (ME) and anaerobic threshold (AT) were calculated. At a submaximal intensity load of 70 W, VO(2) (l/min) was larger in the obese women and was already 78% of their peak VO(2), whereas in the non-obese it was only 69% (P=0.0001). VE (l/min) was larger, VE/VO(2) did not differ and ME was lower in obese compared to the lean women. AT occurred at the same percentage of peak VO(2) in both lean and obese women. At peak effort, achieved load, terminal VO(2) (l min(-1) kg(-1)), VE, heart rate, RQ respiratory exchange ratio and perceived exertion were lower in obese subjects compared to the non-obese. Obese subjects mentioned significantly more musculoskeletal pain as a reason to end the test, whereas in lean subjects it was leg fatigue. Lean women recovered better as after 2 min they were already at 35% of the peak VO(2), whereas in the obese women it was 47% (P=0.0001). Our results confirm that exercise capacity is decreased in obesity, both at submaximal and peak intensity, and during recovery. Moreover, at peak effort musculoskeletal pain was an important reason to end the test and not true leg fatigue. These findings are important when designing exercise programs for obese subjects.

Bone mass and lifetime physical activity in Flemish males: a 27-year follow-up study.

PURPOSE: The present population study is conducted to examine the extent to which lifetime physical activity and lifestyle parameters contribute to bone mass. METHODS: The design of the project is a 27-yr prospective follow-up study. Subjects are 126 males gathered from the Leuven Longitudinal Study on Lifestyle, Physical Fitness and Health, and aged 13 yr at the onset of the study and 40 at the end of the follow-up. Physical activity and lifestyle parameters are obtained with questionnaires. Bone mass is measured by means of dual-energy x-ray absorptiometry (DXA). RESULTS: Results from correlation and regression analyses show that the body mass index (BMI) is the most important parameter in relation to cortical and trabecular bone mass at every examination period. Longitudinally, static arm strength, running speed, and upper muscular endurance contribute significantly to the prediction of adult bone mass. The parameter "change in motor fitness" between 18 and 13 yr old was used to control for hereditary influences. The score for static arm strength and trunk muscle strength demonstrates a significant correlation with adult total bone mineral content (BMC) and lumbar bone mineral density (BMD), respectively. At the age of 40, the Baecke sports index is almost equally important as BMI in explaining the variance in BMD, and static arm strength is the most important parameter (after BMI) for BMC. CONCLUSION: Lifetime physical activity, physical fitness, and BMI all contribute to adult bone mass. The clinical relevance of these findings is emphasized by the fact that the observed patterns of physical activity and motor fitness pertain to customary lifestyle and are thus feasible targets.

Premorbid "overactive" lifestyle in chronic fatigue syndrome and fibromyalgia. An etiological factor or proof of good citizenship?

OBJECTIVE: In a former study, we have shown that patients suffering from chronic fatigue syndrome (CFS) or chronic pain, when questioned about their premorbid lifestyle, reported a high level of "action-proneness" as compared to control groups. The aim of the present study was to control for the patients' possible idealisation of their previous attitude towards action. METHODS: A validated Dutch self-report questionnaire measuring "action-proneness" (the HAB) was completed by 62 randomly selected tertiary care CFS and fibromyalgia (FM) patients, as well as by their significant others (SOs). RESULTS: HAB scores of the patients and those of the SOs were very similar and significantly higher than the norm values. Whether or not the SO showed sympathy for the patient's illness did not influence the results to a great extent. SOs with a negative attitude towards the illness even characterized the patients as more "action-prone." CONCLUSIONS: These results provide further support for the hypothesis that a high level of "action-proneness" may play a predisposing, initiating and/or perpetuating role in CFS and FM.

Adolescent physical performance and adult physical activity in Flemish males.

Limited information is available about the associations between adolescent fitness levels and adult physical activity. In the present study, these associations are investigated using different indicators of physical activity. It is hypothesized that both health- and performance-related fitness characteristics, observed during the adolescent period, contribute equally to the explained variance in adult physical activity levels. Subjects were 109 Flemish males followed over a period of 27 years from 13 to 40 years of age in the Leuven Longitudinal Study on Lifestyle Fitness and Health. Performance and health-related fitness characteristics were observed during the growth period and at 40 years of age. The Work Index, Leisure Time Index, and Sport Index of the Baecke questionnaire were used as indicators of physical activity together with triaxial accelerometry. Multiple regression and discriminant analyses contrasting extreme quintiles of activity groupings were used to analyse the associations. Only the Baecke Sport Index showed consistent significant associations (R2 = 0.03 to R2 = 0.23) with adolescent fitness levels observed at 13, 15, and 18 years. When upper and lower quintiles were contrasted, fitness characteristics observed at the three age levels during adolescence were significantly different for each of the three indices of the Baecke questionnaire at 40 years of age. Lowest associations (R2 = 0.09 to R2 = 0.17) were found for the Work Index, followed by the Leisure Time Index (R2 = 0.12 to R2 = 0.28) and Sport Index (R2 = 0.25 to R2 = 0.43). Highest associations were evident for the 18- to 40-year interval. Performance- and health-related fitness characteristics explain equally well the variance in physical activity indicators.

Long-term fluctuations of pressure pain thresholds in healthy men, normally menstruating women and oral contraceptive users.

The aim of this investigation was to evaluate whether the pressure pain threshold (PPT) in masticatory muscles of symptom-free subjects was influenced by fluctuations of the sex hormones. The PPT was measured with an electronic algometer for at least 10 consecutive menstrual cycles in 10 women using oral contraceptives and 10 women not using oral contraceptives, with a regular menstrual cycle (26-31 days). In addition, 10 men were measured in a regular pattern over a period of 1 year. All subjects were symptom-free with an age range between 18 and 39 years. Measurement sessions were held during three different cycle phases (follicular, luteal, perimenstrual) and each session consisted of four consecutive PPT measurements. By means of a linear mixed model (SAS), the PPTs of the masster, temporalis and thumb muscles were compared between: (1) groups, (2) sex-hormonal phases, (3) the four consecutive measurements of each muscle per session and (4) time. The PPTs of the masseter (p = 0.8419) and temporalis muscles (p = 0.2786) did not change significantly over time. There was no significant difference in variance for the masseter (p = 0.6250), temporalis (p = 0.9705) and thumb (p = 0.7446) between the three groups. The PPTs of all muscles were significantly lower during the perimenstrual phases in the two female groups. The present data showed similar patterns of PPTs for the three muscle groups. Moreover, the results have shown a very good consistency of the PPTs over a long time period, both in males and females.

Lumbosacral pain in an athlete.

This report presents a case of a stress fracture in the sacrum. The diagnosis of a stress fracture in the sacrum is an uncommon localization and has been reported infrequently in the English literature. Association of this type of stress fracture with a pneumatocyst has not previously been reported.

Study of differences in peripheral muscle strength of lean versus obese women: an allometric approach.

OBJECTIVE: To investigate whether peripheral muscle strength is significantly different between lean and obese women controlled for age and physical activity, using an allometric approach. DESIGN: Cross-sectional study of isometric handgrip and isokinetic leg and trunk muscle strength. SUBJECTS: 173 obese (age 39.9+/-11.4 y, body mass index (BMI) 37.8+/-5.3 kg/m(2)) and 80 lean (age 39.7+/-12.2 y, BMI 22.0+/-2.2 kg/m(2)) women. MEASUREMENTS: Anthropometric measures (weight, height) and body composition (bioelectrical impedance method), isometric handgrip (maximal voluntary contraction on the Jamar dynamometer), isokinetic trunk flexion-extension, trunk rotation, and knee flexion-extension (Cybex dynamometers). RESULTS: Absolute isokinetic strength output (that is, strength uncorrected for fat-free mass) was larger in obese compared to lean women, except for knee flexion and isometric handgrip, which were not significantly different (P>0.05). Pearson correlation coefficients between strength measures and fat-free mass (kg) were low to moderate both in lean (r=0.28-0.53, P<0.05) and in obese (r=0.29-0.49, P<0.001) women. There was no correlation with fat mass (kg) in the lean, whereas in the obese women a weak positive relation could be observed for most isokinetic data (r=0.21-0.39, P<0.01). When correcting for fat-free mass (raised to the optimal exponent determined by allometric scaling), all strength measurements were at least 6% lower in obese when compared to the lean women, except for trunk flexion, which was at least 8% stronger in obese women. DISCUSSION: The higher absolute knee extension strength measures of leg and the similar extension strength of the trunk in the obese sample compared to the lean might be explained by the training effect of weight bearing and support of a larger body mass. However when the independent effect of fat-free mass is removed, these strength measures, as well as oblique abdominal muscle and handgrip strength, turned out to be lower in obese women. These observations could be the reflection of the overall impairment of physical fitness as a consequence of obesity and its metabolic complications.

Intrinsic risk factors for the development of patellar tendinitis in an athletic population. A two-year prospective study.

Retrospective studies have suggested various factors that might cause a disposition to develop patellar tendinitis, but no prospective data exist to determine any relationships. The purpose of this study was to determine the intrinsic risk factors for the development of patellar tendinitis in an athletic population. Before the study, 138 male and female students of physical education were evaluated for anthropometric variables, leg alignment characteristics, and muscle tightness and strength parameters. During the 2-year study, 19 of the 138 students developed patellar tendinitis. In all cases the diagnosis was confirmed by the presence of a hypoechogenic nodular lesion in the proximal region of the patellar tendon. Univariate and stepwise discriminant function analyses were performed comparing the various measurements. These analyses revealed that the only significant determining factor was muscular flexibility, with the patellar tendinitis patients being less flexible in the quadriceps and hamstring muscles (P < 0.05). The results of this study demonstrate that lower flexibility of the quadriceps and hamstring muscles may contribute to the development of patellar tendinitis in an athletic population. Therefore, the prevention of this condition in athletes should be focused on screening for and treating poor quadriceps and hamstring muscle flexibility.

Trends in BMI among Belgian children, adolescents and adults from 1969 to 1996.

OBJECTIVE: To document secular data on changes in the distribution of body mass index (BMI), to determine the probability of overweight at 40 y of age in Belgian males in relation to the presence or absence of overweight at different ages in adolescence, and to estimate tracking of BMI in Belgian males in Belgium aged 12-40 y. DESIGN: Cross-sectional and mixed longitudinal surveys in nationally representative samples of Belgian males and females. SUBJECTS: Cross-sectional-more than 21 000 boys and 9698 girls; to examine secular trends-3164 boys and 5140 girls; to examine tracking-161 males. MEASURES: Body mass and height to determine BMI. RESULTS: In Belgian children the degree of overweight has increased between 1969 and 1993. Tracking of BMI is high in adolescence (r=0.77) and adulthood (r=0.69-0.91) and moderate from adolescence to adulthood (r=0.49). In Belgian males, the probability of overweight at 40 y of age in the presence of overweight at different ages in adolescence is important (odds ratios 5.0-6.9). CONCLUSIONS: Cross-sectional and longitudinal data, trends and tracking of BMI from 1969 until 1996 in Belgium indicate an increase in the degree of childhood overweight and obesity. Moreover, the risk of an overweight male adolescent becoming an overweight adult is substantial. Measures to restrict the Belgian overweight and obesity epidemic should be taken.

Victimization in chronic fatigue syndrome and fibromyalgia in tertiary care: a controlled study on prevalence and characteristics.

The authors studied the prevalence and characteristics of different forms of victimization in 95 patients suffering from chronic fatigue syndrome (CFS) or fibromyalgia (FM) compared with a chronic disease group, including rheumatoid arthritis (RA) and multiple sclerosis (MS) patients, and a matched healthy control group. The authors assessed prevalence rates, nature of victimization (emotional, physical, sexual), life period of occurrence, emotional impact, and relationship with the perpetrator by a self-report questionnaire on burdening experiences. CFS and FM patients showed significantly higher prevalences of emotional neglect and abuse and of physical abuse, with a considerable subgroup experiencing lifelong victimization. The family of origin and the partner were the most frequent perpetrators. With the exception of sexual abuse, victimization was more severely experienced by the CFS/FM group. No differences were found between healthy control subjects or RA/MS patients, and between CFS and FM patients. These findings support etiological hypotheses suggesting a pivotal role for chronic stress in CFS and FM and may have important therapeutic implications.

Open versus closed kinetic chain exercises for patellofemoral pain. A prospective, randomized study.

The goal of this prospective study was to evaluate the efficacy of open versus closed kinetic chain exercises in the nonoperative management of patellofemoral pain. Sixty patients were randomized into a 5-week program that consisted of only closed kinetic chain exercises or only open kinetic chain exercises. Muscle characteristics, subjective symptoms, and functional performance were evaluated in this study at the time of the initial physical examination, at the end of the treatment period, and 3 months later. Both groups experienced a statistically significant decrease in pain and an increase in functional performance. This study shows that both open and closed kinetic chain exercise programs lead to an improved subjective and clinical outcome in patients with anterior knee pain. The few significantly better functional results for some of the tested parameters in the closed kinetic chain group suggest that this type of treatment is a little more effective than the open kinetic chain program in the treatment of these patients.

Intrinsic risk factors for the development of anterior knee pain in an athletic population. A two-year prospective study.

Many variables have retrospectively been associated with the presence of anterior knee pain. Very few prospective data exist, however, to determine which of these variables will lead to the development of anterior knee pain. It was our purpose in this study to determine the intrinsic risk factors for the development of anterior knee pain in an athletic population over a 2-year period. Before the start of training, 282 male and female students enrolled in physical education classes were evaluated for anthropometric variables, motor performance, general joint laxity, lower leg alignment characteristics, muscle length and strength, static and dynamic patellofemoral characteristics, and psychological parameters. During this 2-year follow-up study, 24 of the 282 students developed patellofemoral pain. Statistical analyses revealed a significant difference between those subjects who developed patellofemoral pain and those who did not concerning quadriceps and gastrocnemius muscle flexibility, explosive strength, thumb-forearm mobility, reflex response time of the vastus medialis obliquus and vastus lateralis muscles, and the psychological parameter of seeking social support. However, only a shortened quadriceps muscle, an altered vastus medialis obliquus muscle reflex response time, a decreased explosive strength, and a hypermobile patella had a significant correlation with the incidence of patellofemoral pain. We concluded that the latter four parameters play a dominant role in the genesis of anterior knee pain and we therefore deem them to be risk factors for this syndrome.

Suprascapular neuropathy in volleyball players.

BACKGROUND: Suprascapular nerve entrapment with isolated paralysis of the infraspinatus muscle is uncommon. However, this pathology has been reported in volleyball players. Despite a lack of scientific evidence, excessive strain on the nerve is often cited as a possible cause of this syndrome. Previous research has shown a close association between shoulder range of motion and strain on the suprascapular nerve. No clinical studies have so far been designed to examine the association between excessive shoulder mobility and the presence of this pathology. AIM: To study the possible association between the range of motion of the shoulder joint and the presence of suprascapular neuropathy by clinically examining the Belgian male volleyball team with respect to several parameters. METHODS: An electromyographic investigation, a clinical shoulder examination, shoulder range of motion measurements, and an isokinetic concentric peak torque shoulder internal/external rotation strength test were performed in 16 professional players. RESULTS: The electrodiagnostic study showed a severe suprascapular neuropathy in four players which affected only the infraspinatus muscle. In each of these four players, suprascapular nerve entrapment was present on the dominant side. Except for the hypotrophy of the infraspinatus muscle, no significant differences between the affected and non-affected players were observed on clinical examination. Significant differences between the affected and non-affected players were found for range of motion measurements of external rotation, horizontal flexion and forward flexion, and for flexion of the shoulder girdle (protraction); all were found to be higher in the affected players than the non-affected players. CONCLUSIONS: This study suggests an association between increased range of motion of the shoulder joint and the presence of isolated paralysis of the infraspinatus muscle in volleyball players. However, the small number of patients in this study prevents definite conclusions from being drawn.