摘要:

Etiology, diagnosis and treatment of tendonitis: an analysis of the literature.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1183-1190, 1998. Tendonitis is a common diagnosis in sports medicine. The traditional view of tendonitis is a tendon injury resulting from repetitive mechanical load with a subsequent inflammatory response. The English literature from 1966 to the present on the etiology, diagnosis, and treatment of tendonitis was evaluated. There is some scientific support in the literature for the diagnosis of tenosynovitis and tendinosis as a pathologic entity. Actual inflammation of tendon tissue consistent with tendonitis has not been seen clearly in patho-anatomic studies. Conclusive evidence confirming that repetitive mechanical load is a major etiologic factor could not be found. Similarly, strength deficits, inflexibility, and improper equipment have not been studied in a controlled prospective manner. Other factors such as age and tendon vascularity have been consistently correlated with these injuries although their overall importance remains difficult to assess. There are no controlled studies on treatment through physical therapy aimed at flexibility and/or strengthening. Treatment with anti-inflammatory drugs has been studied extensively. However, only nine of 32 studies are prospective and placebo controlled. Some pain relief was found in five of the nine controlled studies, but healing of the tendon problem was not studied in these short follow-up studies. Twenty-three studies on steroid injections were found. Eight were prospective and placebo controlled studies, with three showing beneficial effects of the injection at follow-up. It was concluded that much of the pathology and etiology of tendonitis remains unclear. The possibility must be considered that current treatment methods may not significantly affect the natural history.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Assessment of energy expenditure in overweight women.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1191-1197, 1998.Purpose:To compare field measures of average daily energy expenditure (ADEE) against criterion data by the doubly labeled water method (DLW) in overweight women.Methods:The subjects were 20 overweight (BMI 29.2 ± 3.0 kg·m−2) premenopausal women. Energy expenditure was measured by DLW and by the factorial method (activity diary, two techniques differing by method to obtain resting energy expenditure, REE), heart-rate monitoring (HR, two techniques differing by the FLEX-point to discriminate sedentary and activity HR), accelerometer, and pedometer.Results:The ADEEDLWwas 10.26 ± 1.1 MJ·d−1. The mean bias (ADEE by the alternative minus ADEEDLW) was smallest for the accelerometer (+0.08± 1.63 MJ) and HR-FLEX10(+0.11 ± 1.67 MJ). The HR-FLEX0technique (lower FLEX-point) overestimated ADEE by +1.18 (± 1.97 MJ). However, the random error (SD of bias) was smallest for both factorial techniques (REE measured:−0.48 ± 0.81 MJ; REE calculated from the WHO equation: −0.22 ± 0.88 MJ).Conclusions:The results show that simple factorial methods may assess ADEE with small random errors in populations with a rather narrow range of physical activity. The accelerometer and HR with the higher FLEX-point gave comparable results with smaller bias but larger random error compared with the factorial techniques.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Effects of the level of dietary fat intake and endurance exercise on plasma cytokines in runners.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1198-1204, 1998.Purpose:Chronic exercise and high fat diets have been associated with immune suppression. We have reported the effects of level of dietary fat and exercise on lymphocyte subsets, proliferative response, andin vitroproduction of cytokines by peripheral blood mononuclear cells of runners. The present study was planned to further investigate whether the mechanisms of action of dietary fats is through their modulation of plasma cytokines in runners.Methods:This study compared plasma cytokines at rest and after endurance exercise at 80% of V˙O2maxin female(N= 8-10) and male (N= 8-10) runners after eating diets comprised of 17% (LF), 32% (MF), and 41% (HF) fats (4 wk each).Results:The level of interleukin-1β (IL-1β) was independent of gender, exercise, and level of dietary fat. Tumor necrosis factor (TNF-α) level was higher in the plasma of men compared with that in women runners, and the level of these two cytokines increased with increasing level of dietary fat. Plasma interleukin-2 (IL-2) level(a cytokine involved in enhancingTcell functions for host defense) was significantly higher in men compared with that in women runners and decreased in men with increased dietary fat. Plasma interleukin-6 (IL-6) level was significantly lower after the endurance run, and IL-6 levels decreased with increase in dietary fat.Conclusions:Data from the present study suggest that dietary fat has differential effects on plasma cytokine levels in runners. Increasing the level of dietary fat significantly increased endurance run time and had no adverse effects on the level of plasma IL-2 and pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) in runners.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Exercise training reduces myocardial lipid peroxidation following short-term ischemia-reperfusion.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1211-1216, 1998.Purpose:The purpose of these experiments was to test the hypothesis that endurance exercise training will reduce myocardial lipid peroxidation following short-term ischemia and reperfusion(I-R).Methods:Female Sprague-Dawley rats (4 months old) were randomly assigned to either a sedentary control group (N= 13) or to an exercise training group (N= 13). The exercise trained animals ran 4 d·wk−1(90 min·d−1) at ∼75% of V˙O2max. Following a 10-wk training program, animals were anesthetized, mechanically ventilated, and the chest was opened by thoracotomy. Coronary occlusion was achieved by a ligature around the left coronary artery; occlusion was maintained for 5 min followed by a 10-min period of reperfusion.Results:Although training did not alter (P> 0.05) myocardial activities of antioxidant enzymes (superoxide dismutase and glutathione peroxidase), training was associated with significant increases (P< 0.05) in heat shock protein (HSP72) in the left ventricle. Compared with controls, trained animals exhibited significantly lower levels (P< 0.05) of myocardial lipid peroxidation following I-R.Conclusions:These data support the hypothesis that exercise training provides protection against myocardial lipid peroxidation induced by short-term I-Rin vivo.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Correlation between contractile strength and myosin heavy chain isoform composition in human skeletal muscle.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1217-1222, 1998.Purpose:The purpose of this study was to investigate the relationship between myosin heavy chain (MHC) composition and maximal contraction strength of the human quadriceps femoris muscle.Methods:Muscle biopsies were obtained from m. vastus lateralis in young highly physical active males(N= 7). The MHC composition of muscle homogenates was determined by electrophoresis techniques (SDS-PAGE). Isokinetic peak torque and constant-angle torque (50° knee flexion) were obtained during slow (30°·s−1), medium (120°·s−1), and fast (240°·s−1) maximal concentric and eccentric quadriceps contractions and expressed relative to muscle volume.Results:The percentage of MHC II in the quadriceps muscle was positively correlated (rs= 0.61-0.93;P< 0.05-0.01) to maximal concentric quadriceps strength obtained at medium to high knee angular velocity. In contrast, no consistent pattern of correlation was observed for maximal eccentric quadriceps strength.Conclusions:The relationship observed between muscular MHC composition and maximal contractile strength is suggested to appear as a consequence of MHC-related differences in contractile force-velocity characteristics and/or contractile Rate of Force Development (RFD).

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Is there a threshold between peak oxygen uptake and self-reported physical functioning in older adults?Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1223-1229, 1998.Purpose:Few studies have examined the relationship between directly measured oxygen uptake (V˙O2) and self-reported physical function (PF). The purpose of this study was: 1) to examine the relationship between peak V˙O2and PF and 2) to determine whether a threshold or cut point exists that distinguishes between individuals reporting required assistance in the performance of functional tasks (low PF) and those who report ability to perform tasks independently (high PF).Methods:Participants were 161 community-dwelling adults, ages 65-90, who had a baseline evaluation for a clinical trial that included measurement of peak V˙O2and PF. PF consisted of a summary score combining scores from the Older Americans Resources and Services Multidimensional Functional Assessment Questionnaire, Nagi Disability Study, Rosow-Breslau Scale, Physical Function Scale of the Medical Outcomes Study, and the Falls Efficacy Scale. Decision tree, cubic spline, and logistic regression analyses explored these relationships with age, gender, education, race, body mass index, depression, and total number of chronic diseases included as important covariates.Results:Among all covariates examined, peak V˙O2was most strongly associated with (P= 0.004) with PF. There was no threshold effect. Decision tree analyses indicated that 18.3 mL·kg−1·min−1was the optimal cut point distinguishing between low PF and high PF (P< 0.0001). Between-gender differences in PF (P= 0.002) were no longer significant when peak V˙O2was included in the PF model (P= 0.17).Conclusions:These data indicate that individuals with a peak V˙O2< 18 mL·kg−1·min−1report significant difficulty in the performance of daily tasks and that differences in peak V˙O2may explain, in part, why women report more impairment in PF.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Effect of heart failure on muscle capillary geometry: implications for O2exchange.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1230-1237, 1998. There is strong evidence that chronic heart failure (CHF) impairs skeletal muscle function independent of blood flow and bulk O2delivery.Purpose:This investigation sought to determine whether alterations in muscle capillary geometry and surface area that are thought to be primary determinants of the efficacy for blood-tissue O2exchange might be altered in CHF and contribute to these changes.Methods:Plantaris(fast twitch) and soleus (slow twitch) muscles from control (C) and 6- to 7-wk post myocardial infarcted (CHF) rats were perfusion-fixed in situ. These muscles were analyzed using morphometric techniques that facilitated determination of muscle sarcomere length, fiber cross-sectional area, capillary tortuosity and branching coefficient(c(K,0)), capillary length, volume, and surface area.Results:Normalized to a sarcomere length of 2.1 μm, plantaris fiber cross-sectional area decreased by 21% (P< 0.05), and capillary-to-fiber ratio decreased from 2.05± 0.07 in C to 1.79 ± 0.04 (P< 0.05) in CHF, but these variables were unchanged in soleus. There was no change in c(K,0) or capillary diameter in either muscle, and thus capillary length and surface area per fiber volume remained unchanged. From the measured fiber atrophy and capillary involution in plantaris reductions of total muscle capillary length, volume, and surface area of 11%, 9% and 17%, respectively, are estimated.Conclusion:These changes, coupled with reduced blood flow may impair the effective matching of muscle fiber O2delivery to O2requirement during repeated muscle contractions(i.e., exercise). This scenario is expected to reduce intramyocyte O2partial pressure and thereby contribute to the greater fatigability characteristic of the CHF condition.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Comparison of a computerized physical activity recall with a triaxial motion sensor in middle-school youth.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1238-1245, 1998.Purpose:To develop and test a computerized activity recall (CAR) for capturing activity and energy expenditure (EE) in youth and to further our understanding of the use of the three-dimensional accelerometer (Tritrac®) for studying activity and EE.Methods:Forty-five students (25 girls and 20 boys) in grades 6-8, completed 5 consecutive days of the CAR and were randomly assigned to wear the Tritrac during 1 day in which they also completed the CAR. Twenty-two subjects also repeated 5 d of the CAR and 1 d of Tritrac monitoring 1-2 wk later.Results:The correlation between the CAR and Tritrac for total EE was significant (r = 0.510,P= 0.0003). However, the total EE computed from the Tritrac was significantly greater than the CAR (1941 ± 273 kcal vs 1576 ± 343 kcal (8.14 ± 1.14 vs 6.60± 1.44 MJ);P< 0.001). The EE of activities was similar for the Tritrac and CAR, ∼670 kcal (2.80 MJ), suggesting that the difference between the two methods was their estimates of resting EE. Comparison of the CAR and Tritrac for classifying active and inactive subjects indicated that both methods similarly classified 35 of the 45 subjects or 78% (P= 0.0038). Although significant, the Kappa statistic (κ = 0.398) indicated a low-level of agreement between methods. The Tritrac indicated 50.4 ± 29.2 min·d−1of activities of ⩾3 METs, whereas the CAR indicated 76.7 ± 71.9 min·d−1(P= 0.02). The week 1 vs 2 test-retest correlation was 0.485 (P= 0.022) for the Tritrac and 0.820 (P= 0.0001) for the CAR.Conclusions:It appears that both methods have acceptable reliability. However, the validity of each method to measure total and activity EE remains unclear, as the Tritrac appears to overestimate resting energy expenditure, whereas the CAR overestimates total minutes of activity.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Injury rates from walking, gardening, weightlifting, outdoor bicycling, and aerobics.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1246-1249, 1998.Purpose:The objective of this survey was to estimate the frequency of injuries associated with five commonly performed moderately intense activities: walking for exercise, gardening and yard work, weightlifting, aerobic dance, and outdoor bicycling.Methods:National estimates were derived from weighted responses of over 5,000 individuals contacted between April 28 and September 18, 1994, via random-digit dialing of U.S. residential telephone numbers. Self-reported participation in these five activities in the late spring and summer of 1994 was common, ranging from an estimated 14.5 ± 1.2% of the population for aerobics (nearly 30 million people) to 73.0 ± 1.5% for walking (about 138 million people).Results:Among participants, the activity-specific 30-d prevalence of injury ranged from 0.9 ± 0.5% for outdoor bicycle riding to 2.4 ± 1.3% for weightlifting. The estimated number of people injured in the 30 d before their interview ranged from 330,000 for outdoor bicycle riding to 2.1 million for gardening or yard work. Incidence rates for injuries causing reduced participation in activity were 1.1 ± 0.5·100 participants·30 d for walking, 1.1 ± 0.4 for gardening, and 3.3 ± 1.9 for weightlifting. During walking and gardening, men and women were equally likely to be injured, but younger people (18-44 yr) were more likely to be injured than older people (45+ yr). Injury rates were low, yet large numbers of people were injured because participation rates were high. Most injuries were minor, but injuries may reduce participation in these otherwise beneficial activities.Conclusions:Additional studies to confirm the magnitude of the problem, to identify modifiable risk factors, and to recommend methods to reduce the frequency of such injuries are needed.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Improved running economy following intensified training correlates with reduced ventilatory demands.Med. Sci. Sports Exerc.,Vol. 30, No. 8, pp. 1250-1256, 1998.Purpose:To compare the effects of three types of intensive run training on running economy (RE) during exhaustive running and to establish possible relationships with changes in ventilatory function and/or muscle fiber type distribution.Methods:Thirty-six male recreational runners were divided into three groups and assigned to either exhaustive distance training (DT), long-interval training (LIT), or short-interval training(SIT) three times 20-30 min·wk−1for 6 wk. V˙O2maxand RE were measured during treadmill running before and after training. Muscle fiber type distribution of the vastus lateralis muscle was established from biopsy material.Results:V˙O2max(L·min−1) increased by 5.9% (P< 0.0001), 6.0%(P< 0.0001), and 3.6% (P< 0.01) in DT, LIT, and SIT, respectively, and running speed at V˙O2maxby 9% (P< 0.0001), 10% (P< 0.0001), and 4% (P< 0.05), respectively. Time-to-exhaustion at 87% of pretraining V˙O2max(mean 3.83 m·s−1) increased by 94% in DT (P< 0.0001), 67% in LIT (P< 0.0001), and 65% in SIT (P< 0.001). Running economy improved by 3.1% in DT (P< 0.05), 3.0% in LIT (P< 0.01), and 0.9% in SIT (NS); pulmonary ventilation (V˙E) was on average 11 L·min−1lower following training (P< 0.0001). The individual decrements in V˙E correlated with improvements in RE (r = 0.77;P< 0.0001) and may account for 25-70% of the decrease in aerobic demand. Muscle fiber composition, and respiratory exchange ratio, stride length, and stride frequency during running were unaltered with training.Conclusion:Recreational runners can improve RE and aerobic run performance by exchanging parts of their conventional aerobic distance training with intensive distance or long-interval running, whereas short-interval running is less efficient. The improvement in RE may relate to reduced ventilatory demands. Muscle fiber type distribution was unaltered with training and showed no association with RE.

ISSN:0195-9131    

出版商:OVID    

年代:1998

数据来源: OVID