ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThis article discusses the possible association between impact forces and foot pronation and the development of running-related injuries, and proposes a new paradigm for impact forces and foot pronation.Data SourcesThe article is based on a critical analysis of the literature on heel–toe running addressing kinematics, kinetics, resultant joint movements and forces, muscle activity, subject and material characteristics, epidemiology, and biologic reactions. However, this paper is not a review of the literature but rather an attempt to replace the established concepts of impact forces and movement control with a new paradigm that would allow explaining some of the current contradictions in this topic of research.Study SelectionThe analysis included all papers published on this topic over the last 25 years. For the last few years, it concentrated on papers expressing critical concerns on the established concepts of impact and movement control.Data ExtractionAn attempt was made to find indications in the various publications to support or reject the current concept of impact forces and movement control. Furthermore, the results of the available studies were searched for indications expanding the current understanding of impact forces and movement control in running.Data SynthesisData were synthesized revealing contradictions in the experimental results and the established concepts. Based on the contradictions in the existing research publications, a new paradigm was proposed.ConclusionTheoretical, experimental, and epidemiological evidence onimpact forcesshowed that one cannot conclude that impact forces are important factors in the development of chronic and/or acute running-related injuries. A new paradigm for impact forces during running proposes that impact forces are input signals that produce muscle tuning shortly before the next contact with the ground to minimize soft tissue vibration and/or reduce joint and tendon loading. Muscle tuning might affect fatigue, comfort, work, and performance. Experimental evidence suggests that the concept of “aligning the skeleton” with shoes, inserts, and orthotics should be reconsidered. They produce only small, not systematic, and subject-specific changes of foot and leg movement. A new paradigm for movement control for the lower extremities proposes that forces acting on the foot during the stance phase act as an input signal producing a muscle reaction. The cost function used in this adaptation process is to maintain a preferred joint movement path for a given movement task. If an intervention counteracts the preferred movement path, muscle activity must be increased. An optimal shoe, insert, or orthotic reduces muscle activity. Thus, shoes, inserts, and orthotics affect general muscle activity and, therefore, fatigue, comfort, work, and performance. The two proposed paradigms suggest that the locomotor system use a similar strategy for “impact” and “movement control.” In both cases the locomotor system keeps the general kinematic and kinetic situations similar for a given task. The proposed muscle tuning reaction to impact loading affects the muscle activationbeforeground contact. The proposed muscle adaptation to provide a constant joint movement pattern affects the muscle activationduringground contact. However, further experimental and theoretical studies are needed to support or reject the proposed paradigms.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveFlexion and erect standing radiographs were evaluated in the current study to compare their sensitivity in detecting articular cartilage wear.DesignProspective cohort study.SettingA tertiary care hospital outpatient orthopedic clinic.PatientsAll patients with osteoarthritis of the knee ages 40 to 75 scheduled for arthroscopic debridement between March 1995 and November 1997 were considered for the current study.InterventionRadiographs were obtained 1 week preoperatively in both the 3-foot standing anteroposterior (AP) and a 45° posteroanterior (PA) flexion weight-bearing projection. Joint space height was measured with a ruler in millimeters at the narrowest point of each compartment. All radiographs were assessed by two independent observers who were blinded to the arthroscopic findings and clinical symptoms of the subjects.Main Outcome MeasuresPrediction accuracy of each radiograph for severe Grade IV articular cartilage wear in tibiofemoral compartments.ResultsOne hundred fifty-two patients with a mean (± SD) age of 60.5 ± 8.5 years were enrolled in the study. Fifty-one percent were female. Twelve patients were categorized as having severe lateral compartment articular chondropathy (Grade IV) at the time of arthroscopy. The lateral joint space height averaged 1 .0 ± 1.7 mm SD on the 45° PA radiograph compared with 2.7 ± 1.1 mm SD on the 3-foot standing AP view. Using a cutoff of 2 mm or less, the 45° PA view was much more sensitive (83% versus 42%) at correctly detecting the most severe chondropathy. Forty-one patients were classified with severe Grade IV medial compartment chondropathy at arthroscopy. There was little difference in the average joint space height measured by the 45° PA view (1.4 ± 1.4 mm SD) or the 3-foot standing AP view (1.9 ± 1.6 mm SD). A number of cutoff measures were evaluated, but no significant advantage could be found for either view in evaluating the medial compartment severity.ConclusionsThe bilateral 45° PA is superior for detecting lateral compartment wear but offers no advantage on the medial side. This view should be considered as the screening radiograph of choice in evaluating osteoarthritis of the knee.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo examine the causes of sport-related spinal cord injuries that developed into paraplegia or tetraplegia, and to compare data from different sports with previous studies in the same geographical region.DesignA retrospective epidemiological study and comparison with previous studies.SettingThe Orthopedic Department, specializing in the treatment and rehabilitation of paralyzed patients, at the University of Heidelberg, Germany.ParticipantsBetween 1985 and 1997, 1,016 cases of traumatic spinal cord injury presented at the Orthopedic Department at the University of Heidelberg: 6.8% were caused by sport and 7.7% by diving accidents.Main Outcome MeasuresSport-related spinal cord injuries with paralysis.ResultsA total of 1,016 cases of traumatic spinal cord injury were reviewed. Of these, 14.5% were caused by sport accidents (n = 69) or diving accidents (n = 78). Age of patients ranged from 9 to 52 years. 83% were male. 77% of the patients developed tetraplegia, and 23%, paraplegia. 16 of the sport accidents resulted from downhill skiing, 9 resulted from horseback riding, 7 from modern air sports, 6 from gymnastics, 5 from trampolining, and 26 from other sports. Previous analyses had revealed that paraplegia had mainly occurred from gymnastics, trampolining, or high diving accidents. More recently, however, the number of serious spinal injuries caused by risk-filled sports such as hang gliding and paragliding has significantly increased (p = 0.095), as it has for horseback riding and skiing. Examinations have shown that all patients who were involved in diving accidents developed tetraplegia. An analysis of injury from specific sports is still under way.ConclusionsAnalysis of accidents resulting in damage to the spinal cord in respect to different sports shows that sports that have become popular during the last 10 years show an increasing risk of injury. Modern air sports hold the most injuries. Injury-preventing strategies also are presented.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo examine the utility of neuropsychological tests in assessing college athletes prior to and following a sports-related mild Traumatic Brain Injury (mTBI).DesignA prospective study of college athletes who sustained mTBI while engaged in sport. Preinjury baseline neuropsychological test data were obtained for athletes at risk for mTBI. Following an mTBI, the athlete and his or her matched noninjured control were evaluated at 2 hours, 48 hours, 1 week, and 1 month postinjury.SettingMale and female athletes from a Division I college.ParticipantsMale and female athletes from the football, men's ice hockey, men's and women's soccer, and men's and women's basketball teams at Penn State University. A total of 29 injured and 20 noninjured athletes participated in the study.InterventionsNeuropsychological test batteries were administered at baseline and serially following mTBI.Main Outcome MeasuresPost-Concussion Symptom Checklist, Hopkins Verbal Learning Test, Symbol Digit Modalities Test, Stroop Color-Word Test, Trail Making Test, VIGIL/W, List Learning, Digit Span, Penn State Cancellation Test, and Controlled Oral Word Association.ResultsNeuropsychological test data yielded significant differences between injured athletes and controls at 2 hours and 48 hours following cerebral concussion; injured athletes performing significantly worse than controls. Injured athletes reported a significantly greater number of postconcussion symptoms 2 hours following injury but not at the 48-hour assessment. No multivariate group differences were found at 1 week, but univariate analyses suggested significant differences on a few measures. At 1 month postinjury, a statistically significant difference was found on one measure with injured athletes marginally outperforming controls.ConclusionsNeuropsychological tests are useful in the detection of cognitive impairment following mTBI. The test data appear to be more effective than subjective report of symptoms in differentiating between injured and noninjured athletes at 48 hours postinjury. Although significant individual variability existed, most injured athletes recovered within 1 week of injury. A battery of tests, rather than any single test, is necessary to capture the variability that exists among injured athletes.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveThis study examined eating behavior in collegiate women lightweight rowers, runners, and controls. It was hypothesized that rowers would show an increased prevalence of restraint in their eating behaviors, but not probable eating disorder cases as compared with runners or controls, because they are required to make their target weight but are discouraged from further weight loss.DesignRetrospective survey.Setting/ParticipantsLightweight women rowers (n = 122) at eastern collegiate championship regattas, collegiate distance runners (n = 79) at a regional track meet, and a convenience sample of collegiate controls (n = 95) were surveyed.Main Outcome MeasureThe Eating Disorders Examination-Questionnaire, a validated questionnaire evaluating eating attitudes and behaviors, and additional questions regarding weight and menstrual history were used to assess probable eating disorder cases and disordered eating tendencies.ResultsRowers showed significantly more restraint in eating patterns during the previous month and less shape concern than either runners or controls. Rowers also reported increased use of diuretics. There were no significant differences between groups in terms of probable cases of eating disorders or disordered eating behavior.ConclusionsLightweight rowing and distance running were not associated with increased prevalence of eating disorders in this sample, although rowing was associated with increased restraint and diuretic misuse. This use of pathologic weight-making behaviors is of significant clinical concern. These results support ongoing monitoring of disturbed eating and weight-making practices in weight-dependent sports, but do not support discouraging the growth of lightweight women's rowing at the collegiate level.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveControversy exists in relation to the nature of the acute phase response, which is known to occur following endurance exercise. This study was conducted to demonstrate the similarities between this response and the response consequent to general medical and surgical conditions.DesignThis is a case series field study of serum levels of acute phase reactants in a group of ultramarathon runners competing in a 6-day track race.ParticipantsSeven male and one female experienced ultramarathon runners.InterventionA track race of 6 days duration.Main Outcome MeasuresSerum iron, ferritin, transferrin, albumin, haptoglobin, alpha-1 antitrypsin, complement components 3 and 4, C-reactive protein, and erythrocyte sedimentation rate, total iron binding capacity, and transferrin saturation.ResultsOf the 11 acute phase reactants measured, 6 (serum iron, ferritin, percent transferrin saturation, C-reactive protein, erythrocyte sedimentation rate, and haptoglobin) responded as if an acute phase response was present; 5 (tranferrin, albumin, alpha-1 antitrypsin, and complement components 3 and 4) did not respond in such a fashion.ConclusionThis study provides further evidence that the acute phase response consequent to exercise is analogous to that which occurs in general medical and surgical conditions. The previous demonstration of the presence of the appropriate cytokines following exercise, the findings of others in relation to acute phase reactants not the subjects of this study, the possibility that a training effect leading to attenuation of the response and the realization that the acute phase response is not identical across a range of medical conditions lends weight to the above conclusion.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo record weight changes, fluid intake and changes in serum sodium concentration in ultradistance triathletes.DesignDescriptive research.SettingIronman triathlon (3.8 km swim, 180 km cycle, 42.2 km run). Air temperature at 1200 h was 21°C, (relative humidity 91%). Water temperature was 20.7°C.Participants18 triathletes.InterventionsNone.Main Outcome MeasuresSubjects were weighed and had blood drawn for serum sodium concentration [Na], hemoglobin, and hematocrit, pre-race, post-race, and at 0800 h on the morning following the race (“recovery”); subjects were also weighed at transitions. Fluid intake during the race was estimated by athlete recall.ResultsMedian weight change during the race = −2.5 kg (p < 0.0006). Subjects lost weight during recovery (median = −1.0 kg) (p < 0.03). Median hourly fluid intake = 716 ml/h (range 421–970). Fluid intakes were higher on the bike than on the run (median 889 versus 632 ml/h, p = 0.03). Median calculated fluid losses cycling were 808 ml/h and running were 1,021 ml/h. No significant difference existed between pre-race and post-race [Na] (median 140 versus 138 mmol/L) or between post-race and recovery [Na] (median 138 versus 137 mmol/L). Plasma volume increased during the race, median + 10.8% (p = 0.0005). There was an inverse relationship between change in [Na] pre-race to post-race and relative weight change (r= −0.68, p = 0.0029). Five subjects developed hyponatremia ([Na] 128–133 mmol/L).ConclusionsAthletes lose 2.5 kg of weight during an ultra-distance triathlon, most likely from sources other than fluid loss. Fluid intakes during this event are more modest than that recommended for shorter duration exercise. Plasma volume increases during the ultradistance triathlon. Subjects who developed hyponatremia had evidence of fluid overload despite modest fluid intakes.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

ObjectiveTo determine the substance-use patterns of National Collegiate Athletic Association (NCAA) student-athletes for alcohol, amphetamines, anabolic steroids, cocaine/crack, ephedrine, marijuana/hashish, psychedelics/hallucinogens, and smokeless tobacco.DesignSelf-reported, anonymous, retrospective survey.ParticipantsMale and female student-athletes from 30 sports competing at 991 NCAA Division I, II, and III institutions.Main Outcome MeasuresRespondents were queried about their use of eight categories of substances in the previous 12-month period. In addition, data were collected regarding substance use according to team, ethnicity, NCAA Division, reasons for use, and the sources for drugs.ResultsThe overall response rate was 64.3% with 637 of 991 schools reporting with usable data on 13,914 student-athletes. For the eight categories of substance use, alcohol was the most widely used drug in the past year at 80.5%, followed by marijuana at 28.4%, and smokeless tobacco at 22.5%. Although anabolic steroid use was reported at 1.1% overall, some sports demonstrated higher use, and 32.1% obtained their anabolic steroids from a physician other than the institution's team physician. There were wide variations in the pattern of substance abuse according to sport. The results were also analyzed according to division, and it was found that the likelihood of alcohol, amphetamines, marijuana, and psychedelics use is highest in Division III. In addition, the probability of ephedrine use is highest in both Division II and III, while Division II had the highest likelihood of cocaine use. Finally, the results were analyzed according to ethnicity and we found that the likelihood of use of smokeless tobacco, alcohol, ephedrine, amphetamines, marijuana, and psychedelics is highest for Caucasian student-athletes.ConclusionThe study demonstrates a wide variation of use across NCAA divisions and sports, as well as among ethnic groups. The majority of student-athletes engage in substance use, especially alcohol. According to the survey, substance use is highest among Division III student-athletes and also among Caucasians. By examining reasons for use, the study will assist professionals in designing specific interventions for various substances. This study provides a methodology for surveying a large number of NCAA student-athletes, which will be repeated every 4 years to identify trends in substance abuse.

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:1050-642X    

出版商:OVID    

年代:2001

数据来源: OVID