ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveAnkle joint complex dynamics developed during volleyball spike jumps take-offs and landings were quantified to assess potential relations between these joint dynamics and patellar tendinopathy.DesignThree-dimensional kinematic data provided information about movements of the lower limbs, while the kinetic data permitted analysis of ground reaction forces as players took-off and landed from full-speed spike jumps.SettingSimulated volleyball court with net in a biomechanics research laboratory.Participants10 members of the Canadian Men's National Volleyball Team. From history and physical examination, 3 of the 10 players had patellar tendon pain associated with activity and were diagnosed with patellar tendinopathy at the time of the study. Investigators were blinded about the injury status of the players.InterventionsNone.Main Outcome MeasuresThree-dimensional kinematics and joint moments of the ankle, knee, and hip joints.ResultsOur analysis revealed that maximal external tibial rotation occurred at or near maximal dorsiflexion while maximal internal tibial rotation coincided with maximal plantarflexion. The plantarflexion moment was 3 to 10 times greater than all the other moments measured, with the maximal plantarflexor moment being calculated at 0.4 BWm (360 Nm). In blinded logistic regression analyses, we found one of the dynamics variables (inversion moment during the landing of the spike jump) was a significant predictor of patellar tendinopathy.ConclusionsCoupling the results of the current analysis of ankle joint complex dynamics with previously reported results of knee joint dynamics related to patellar tendinopathy suggests that a cluster of variables linked to patellar tendinopathy includes: high ankle inversion–eversion moments, high external tibial rotation and plantarflexion moments, large vertical ground reaction forces, and high rate of knee extensor moment development.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

PurposeTo assess the long-term ultrasonographic appearance of rupture of the Achilles tendon.Subjects and MethodsWe examined 70 patients at an average of 63 months (range 10–120 months) after rupture of the Achilles tendon. We assessed the patient's contralateral tendon and also performed ultrasonography on the Achilles tendon of 70 age- and sex-matched controls. We recorded the maximum transverse anteroposterior diameter, the presence of intratendinous alterations, and the presence of intratendinous calcification.ResultsThe average maximum anteroposterior diameter of the ruptured tendon was 11.7 mm (SD = 2.10). The patients' normal tendons measured an average of 5.4 mm (SD = 0.9), and there was an average measure of 4.9 mm (SD = 0.5) (p = 0.0001) in the controls. There was no difference in the maximum anteroposterior diameter of the ruptured tendon depending on the method of treatment (conservative, open repair, percutaneous repair). Seventeen patients exhibited areas of hypoechogenicity in their ruptured tendon, two patients had areas of hypoechogenicity in their unruptured contralateral tendon, and 10 patients had calcification in their ruptured tendon.ConclusionThe anteroposterior diameter of the ruptured tendon was significantly greater than the nonruptured contralateral. However, when compared with a group of individually age- and sex-matched controls, the patients' contralateral tendons had significantly greater maximum anteroposterior diameter and had a greater prevalence of intratendinous alterations. This difference may represent a background of subclinical tendinopathy that may predispose to rupture.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveThe objective of this study was to determine whether sodium supplementation 1) influences changes in body weight, serum sodium [Na], and plasma volume (PV), and 2) prevents hyponatremia in Ironman triathletes.SettingThe study was carried out at the South African Ironman triathlon.ParticipantsThirty-eight athletes competing in the triathlon were given salt tablets to ingest during the race. Data collected from these athletes [salt intake group (SI)] were compared with data from athletes not given salt [no salt group (NS)].InterventionsSalt tablets were given to the SI group to provide approximately 700 mg/h of sodium.Main Outcome MeasurementsSerum sodium, hemoglobin, and hematocrit were measured at race registration and after the race. Weights were measured before and after the race. Members of SI were retrospectively matched to subjects in NS for 1) weight change and 2) pre-race [Na].ResultsThe SI group developed a 3.3-kg weight loss (p < 0.0001) and significantly increased their [Na] (&Dgr;[Na] 1.52 mmol/L; p = 0.005). When matched for weight change during the race, SI increased their [Na] compared with NS (mean 1.52 versus 0.04 mmol/L), but this did not reach statistical significance (p = 0.08). When matched for pre-race [Na], SI had a significantly smaller percent body weight loss than NS (−4.3% versus −5.1%; p = 0.04). There was no significant difference in the increase of [Na] in both groups (1.57 versus 0.84 mmol/L). PV increased equally in both groups. None of the subjects finished the race with [Na] < 135 mmol/L.ConclusionsSodium ingestion was associated with a decrease in the extent of weight loss during the race. There was no evidence that sodium ingestion significantly influenced changes in [Na] or PV more than fluid replacement alone in the Ironman triathletes in this study. Sodium supplementation was not necessary to prevent the development of hyponatremia in these athletes who lost weight, indicating that they had only partially replaced their fluid and other losses during the Ironman triathlon.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveIn 1998, the National Collegiate Athletic Association (NCAA) adopted a new rule that required minimum weight testing for collegiate wrestlers. The objective of the study was to cross-validate the method used by the NCAA to estimate minimum weight in collegiate wrestlers.DesignThe NCAA skinfold equation was cross-validated against a criterion value from hydrostatic weighing (HW).SettingThe subjects were tested at the Universities of Wisconsin and Iowa.SubjectsA sample of 93 college wrestlers from the Universities of Wisconsin and Iowa (mean ± SD; age = 20.20 ± 1.67 years, height = 171.98 ± 6.63 cm, weight = 74.44 ± 11.48 kg) were studied.Outcome MeasuresCross-validation included analysis of the standard error of estimate (SEE), total error (TE), and residual plots.ResultsThe mean body fat from the NCAA prediction (10.61 ± 3.58%) was not significantly different than HW (9.70 ± 3.95%). The SEE was low (2.32%), and the TE was low (2.49%). The difference in methods was related to the size of the HW value. The residual plot (y = −0.26x + 3.45, R2= 0.198) suggests that fat is overestimated in the leaner wrestlers and underestimated in fatter wrestlers.ConclusionThe authors found the NCAA method to be a valid predictor of body fat in this sample of 93 collegiate wrestlers under the conditions of the study. Although some bias was seen across the range of fatness, these data support the NCAA method to estimate body fat in college wrestlers for establishment of minimum weight.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveThis study evaluates a sport-specific protocol to evaluate cross-country skiers for exercise-induced asthma (EIA).Study DesignParticipants completed an asthma symptom questionnaire prior to participation. They were then tested by portable digital spirometer with measurements prior to exercise and at 5-minute increments following a 15-minute cross-country skiing exercise session on a groomed ski trail.SettingAll spirometry measurements were collected indoors at Nordic ski areas in the Duluth, Minnesota, area. Each ski area was groomed for both skating and classical technique.Subjects99 high school skiers, 55 female and 44 male, of various skill levels were tested. All were members of their respective high school cross-country ski team. Testing was open to all ski team members. Skiers from seven different high schools participated.Main Outcome MeasuresBronchial hyperresponsiveness to exercise measured by the change in forced expiratory volume at 1 s (FEV1) following exercise. A result was considered positive if the decrement in FEV1 was greater than 10% in any two of the postexercise test increments in comparison with the preexercise baseline.Results28 of 99 (28%) skiers met the criteria for EIA. No significant differences were found with regards to gender, age, or previous experience. Several individual items on the Asthma Symptom Questionnaire were associated with a positive spirometry test.ConclusionsUsing a simple protocol of pre- and postexercise spirometry with a defined exercise challenge, a large number of athletes were screened objectively for this condition. Both the equipment and protocol worked well in the field environment and could easily be adapted to most any sports environment.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo assess change in symptoms, quality of life (QOL), and performance ability before, during, and after treatment with budesonide in a group of Olympic and Paralympic athletes with seasonal allergic rhinoconjunctivitis (SAR/C).DesignBecause budesonide has already been proven to be an effective and well-tolerated treatment of SAR/C,1an open-label treatment format was used.SettingThe study was community-based with participating athletes preparing for Olympic competition.ParticipantsOlympic and Paralympic athletes were screened for the presence of SAR/C using history and positive skin test results for pollen allergens.InterventionsAll were offered treatment with intranasal budesonide, applied to each nostril, once daily for eight weeks.Outcome MeasurementsSymptom and medication diaries were completed before treatment and after 4 and 8 weeks of treatment. Similarly, Quality of Life (QOL) was measured with the Rhinoconjunctivitis Quality of Life Questionnaire. As a secondary outcome measure, the ability to train and compete was assessed using a performance diary.ResultsOf the 236 athletes eligible for the study, 145 (61%) agreed to participate. Forty-six percent of the athletes who were dispensed treatment did not return questionnaires. For those returning questionnaires, scores between baseline (week 0) and weeks 4 and 8 were calculated for total symptoms, QOL, and performance scores.There were statistically significant improvements in symptoms, QOL, and performance scores in athletes who used intranasal budesonide.ConclusionSAR/C is a common condition and has demonstrable negative effects on athletes. Better education of coaches and athletes is necessary to ensure that the condition is correctly diagnosed and treated, with safe, effective, permitted medication.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BackgroundUnaccustomed intense endurance exercise is associated with short-term suppression of natural immunity. However, it is not established whether intensified endurance training alters resting immune status or increases the risk of upper respiratory infection (URI).PurposeThis study examined the effect of intensified endurance training for performance enhancement on resting immune status in nine healthy, male competitive cyclists.DesignData were collected during 4 weeks of usual training (baseline), followed by prescribed cycle training that consisted of volume-building at customary training intensity (V phase, 6 weeks), unaccustomed very high intensity interval training at 100% maximal heart rate (I phase, 18 days), and an unloading taper (U phase, 10 days).MethodsThe main performance criterion was a simulated 20 km time-trial. Aerobic capacity measures included power output at ventilatory threshold (POTvent) and maximal oxygen uptake (VO2max). Markers of immune status (lymphocyte subset counts, serum cytokine levels, and new URI cases) and physiological indicators of training stress (cycling economy, 24-hour urinary cortisol excretion, and serum testosterone concentration) were evaluated in the rested state, 36 to 44 hours postexercise, during baseline, and after each training phase.ResultsTime-trial performance, POTvent, VO2max, and cycling economy improved significantly (p < 0.001) after the V phase, and remained higher than baseline (p < 0.001) after the I and U phases. As compared with the V phase, performance time was faster after the U phase (p < 0.01). In contrast, lymphocyte counts, cytokine levels, incidence of URI, cortisol excretion, and serum testosterone concentration were not significantly different from baseline in any phase.ConclusionsCycling efficiency and performance improved while resting immune status was maintained throughout the 10-week training program. This study provides encouraging data in support of immunological robustness during intensified endurance training.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ObjectiveTo determine whether oxygen consumption during submaximal running increases in proportion to years of accumulated training and racing in masters runners after a bout of downhill running.SettingUniversity of Cape Town, Sports Science Institute of South Africa.ParticipantsSeventeen male masters distance runners (45–55 years) with a range of training (3,536 km to 79,320 km) and racing (205 km to 12,218 km) experience.InterventionA 40-minute continuous treadmill run, at 70% of peak treadmill running speed, consisting of two horizontal runs of 10 minutes each, separated by a 20-minute downhill (−10%) run.Main Outcome MeasuresHeart rate and oxygen consumption were measured continuously during the run. Data were analyzed to identify correlations between the end of the first horizontal section (minute 10) and the first minute of the second horizontal run (minute 31). Delta values were related to current training mileage (km/wk), total accumulated racing distance (km), and total accumulated training distance (km).ResultsThere were significant changes in both heart rate (p < 0.001) and oxygen consumption (p < 0.001) over time during the 40-minute run. There were no significant relationships between the change in oxygen consumption (delta) between minute 10 and minute 31 and total accumulated training mileage, total accumulated racing mileage, and current training.ConclusionsThe results of this study suggest either that submaximal oxygen consumption is not a sensitive marker of changes in neuromuscular activity or that the downhill protocol did not impose a sufficient eccentric stress for the subjects.

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:1050-642X    

出版商:OVID    

年代:2002

数据来源: OVID