ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ZHANG, L.-Q., G. W. NUBER, M. K. BOWEN, J. L. KOH, and J. P. BUTLER. Multiaxis muscle strength in ACL deficient and reconstructed knees: compensatory mechanism.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 2–8.PurposeIt is unclear how muscle strength in tibial rotation and knee abduction change following anterior cruciate ligament (ACL) injury and reconstruction. Such strength changes are likely, considering the oblique orientation of the ACL and the constraint provided by the ACL at various tibial rotation and adduction positions. The purposes of this study were to evaluate multiaxis muscle strength in ACL deficient and reconstructed knees and to gain insights into potential compensatory mechanisms adopted by the patients.MethodsMuscle strength in tibial internal-external rotation, abduction-adduction, and flexion-extension were investigated in 19 chronic ACL deficient, 18 acute ACL deficient, 21 ACL reconstructed, and 23 normal subjects. The strength ratios of flexion/extension, abduction/adduction, and internal/external rotation were determined for each subject and compared across the different populations.ResultsThe chronic ACL deficient patients showed significantly lower strength ratio in internal/external rotation than that of the normal controls and acute ACL deficient subjects (P= 0.02), indicating a compensatory mechanism developed by the patients to unload the ACL and/or to avoid unstable knee positions. For ACL reconstructed patients, the internal/external rotation strength ratio became closer to their counterparts in normal controls than that of chronic ACL deficient patients, presumably reflecting the reduced need for compensation after reconstruction. Furthermore, compared with strength reduction in knee extension, reductions in tibial rotation and abduction strength following ACL reconstruction were less severe and more easy to recover.ConclusionA better understanding of changes in multiaxis muscle strength and the associated compensatory mechanism will help us evaluate treatment outcome more accurately and develop more effective treatment modalities with focus on muscles that help protect and unload the ACL.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

NADLER, S. F., G. A. MALANGA, L. A. BARTOLI, J. H. FEINBERG, M. PRYBICIEN, and M. DEPRINCE. Hip muscle imbalance and low back pain in athletes: influence of core strengthening.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 9–16.PurposeThe influence of a core-strengthening program on low back pain (LBP) occurrence and hip strength differences were studied in NCAA Division I collegiate athletes.MethodsIn 1998, 1999, and 2000, hip strength was measured during preparticipation physical examinations and occurrence of LBP was monitored throughout the year. Following the 1999–2000 preparticipation physicals, all athletes began participation in a structured core-strengthening program, which emphasized abdominal, paraspinal, and hip extensor strengthening. Incidence of LBP and the relationship with hip muscle imbalance were compared between consecutive academic years.ResultsAfter incorporation of core strengthening, there was no statistically significant change in LBP occurrence. Side-to-side extensor strength between athletes participating in both the 1998–1999 and 1999–2000 physicals were no different. After core strengthening, the right hip extensor was, on average, stronger than that of the left hip extensor (P= 0.0001). More specific gender differences were noted after core strengthening. Using logistic regression, female athletes with weaker left hip abductors had a more significant probability of requiring treatment for LBP (P= 0.009)ConclusionThe impact of core strengthening on collegiate athletes has not been previously examined. These results indicated no significant advantage of core strengthening in reducing LBP occurrence, though this may be more a reflection of the small numbers of subjects who actually required treatment. The core program, however, seems to have had a role in modifying hip extensor strength balance. The association between hip strength and future LBP occurrence, observed only in females, may indicate the need for more gender-specific core programs. The need for a larger scale study to examine the impact of core strengthening in collegiate athletes is demonstrated.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

VINCENT, K. R., and R. W. BRAITH. Resistance exercise and bone turnover in elderly men and women.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 17–23.PurposeThis investigation examined the effect of 6 months of high- or low-intensity resistance exercise (REX) on bone mineral density (BMD) and biochemical markers of bone turnover in adults aged 60–83 yr.MethodsSixty-two men and women (68.4 ± 6 yr) were stratified for strength and randomly assigned to a control (CON,N= 16), low-intensity (LEX,N= 24), or high-intensity (HEX,N= 22) group. Subjects participated in 6 months of progressive REX training. Subjects trained at either 50% of their one repetition maximum (1-RM) for 13 repetitions (LEX) or 80% of 1-RM for 8 repetitions (HEX) 3 times·wk−1for 24 wk. One set each of 12 exercises was performed. 1-RM was measured for eight exercises. BMD was measured for total body, femoral neck, and lumbar spine by dual energy x-ray absorptiometry (DXA). Serum levels of bone-specific alkaline phosphatase (BAP), osteocalcin (OC), and pyridinoline cross-links (PYD) were measured.Results1-RM significantly increased for all exercises tested for both the HEX and LEX groups (P≤ 0.050). The percent increases in total strength (sum of all eight 1-RMs) were 17.2% and 17.8% for the LEX and HEX groups, respectively. Bone mineral density (BMD) of the femoral neck significantly (P< 0.05) increased by 1.96% for the HEX group. No other significant changes for BMD were found. OC increased by 25.1% and 39.0% for the LEX and HEX groups, respectively (P< 0.05). BAP significantly (P< 0.05) increased 7.1% for the HEX group.ConclusionThese data indicate high-intensity REX training was successful for improving BMD of the femoral neck in healthy elderly subjects. Also, these data suggest REX increased bone turnover, which over time may lead to further changes in BMD.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

BLANCHET, C., Y. GIGUÈRE, D. PRUD’HOMME, M. DUMONT, F. ROUSSEAU, and S. DODIN. Association of physical activity and bone: influence of vitamin D receptor genotype.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 24–31.PurposeThe aim of the study was to investigate the interaction between leisure physical activity and aBsmIpolymorphism at the vitamin D receptor (VDR) gene on the modulation of bone mineral density (BMD).MethodsWe studied 575 unrelated healthy postmenopausal women. Lumbar spine and femoral neck BMD were measured by dual-energy x-ray absorptiometry (DXA), and results were expressed as age-and-weight-adjusted (Z-score). VDRBsmIgenotype was determined by polymerase reaction chain on peripheral blood leukocytes.ResultsOverall, no significant association was found between the level of leisure physical activity or VDR genotypes and adjusted BMD at both bone sites. However, in active women, there was a trend for an association between VDR genotypes and adjusted BMD at the lumbar spine. Active women, who exercised three times or more a week, carrying the “bb” genotype had a lower BMD at the lumbar spine than active women carrying “BB” genotype (ANOVA;P= 0.04). No significant difference in crude or adjusted BMD at both bone sites was found between VDR genotypes in sedentary or moderately active women. Furthermore, classification of women according to the median-age of the sample (63.1 yr) revealed a significant interaction between the level of leisure physical activity and VDR genotype on adjusted lumbar spine BMD in the older active postmenopausal women (N= 137). Older active women carrying the “bb” genotype showed a lower adjusted BMD at the lumbar spine compared with active women carrying the “BB” genotype (P= 0.007).ConclusionThese results suggested that gene-environment interactions such as leisure physical activity and VDR genotype may play a role in maintaining the BMD at the lumbar spine in active postmenopausal women, especially in older active women.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

THACKER, S. B., J. GILCHRIST, D. F. STROUP, and C. D. KIMSEY. The prevention of shin splints in sports: a systematic review of literature.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 32–40.PurposeTo review the published and unpublished evidence regarding risk factors associated with shin splints, assess the effectiveness of prevention strategies, and offer evidence-based recommendations to coaches, athletes, and researchers.MethodsWe searched electronic data bases without language restriction, identified citations from reference sections of research papers retrieved, contacted experts in the field, and searched the Cochrane Collaboration. Of the 199 citations identified, we emphasized results of the four reports that compared methods to prevent shin splints. We assessed the methodologic quality of these reports by using a standardized instrument.ResultsThe use of shock-absorbent insoles, foam heel pads, heel cord stretching, alternative footwear, as well as graduated running programs among military recruits have undergone assessment in controlled trials. There is no strong support for any of these interventions, and each of the four controlled trials is limited methodologically. Median quality scores in these four studies ranged from 29 to 47, and serious flaws in study design, control of bias, and statistical methods were identified.ConclusionOur review yielded little objective evidence to support widespread use of any existing interventions to prevent shin splints. The most encouraging evidence for effective prevention of shin splints involves the use of shock-absorbing insoles. However, serious flaws in study design and implementation constrain the work in this field thus far. A rigorously implemented research program is critically needed to address this common sports medicine problem.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

LABELLA, C. R., B. W. SMITH, and A. SIGURDSSON. Effect of mouthguards on dental injuries and concussions in college basketball.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 41–44.PurposeDental injuries can be permanent and disfiguring. They are also universally expensive to treat. Many dentists, sports physicians, and athletic trainers recommend mouthguards for athletes participating in certain competitive sports, including men’s college basketball, because of a common perception that mouthguards afford protection from dental injuries, and even some concussions. However, there are few reliable reports of the incidence of dental injuries and concussions in men’s college basketball, and good evidence that mouthguards reduce the risk of these injuries in this population of athletes is notably lacking. This study prospectively recorded dental injuries and concussions among 50 men’s Division I college basketball teams during one competitive season, then compared injury rates between mouthguard users and nonusers.MethodsDuring the 1999 to 2000 basketball season, athletic trainers from 50 men’s Division I college basketball programs used an Internet Web site to submit weekly reports of the number of athlete exposures, mouthguard users, concussions, oral soft tissue injuries, dental injuries, and dentist referrals.ResultsResponse rate was 86%. There were 70,936 athlete exposures. Athletes using custom-fitted mouthguards accounted for 8663 exposures. Injury rates were expressed as number of injuries per 1000 athlete exposures. There were no significant differences between mouthguard users and nonusers in rates of concussions (0.35 vs 0.55) or oral soft tissue injuries (0.69 vs 1.06). Mouthguard users had significantly lower rates of dental injuries (0.12 vs 0.67;P< 0.05) and dentist referrals (0.00 vs 0.72;P< 0.05) than nonusers.ConclusionCustom-fitted mouthguards do not significantly affect rates of concussions or oral soft tissue injuries, but can significantly reduce the morbidity and expense resulting from dental injuries in men’s Division I college basketball.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

ENWEMEKA, C. S., C. ALLEN, P. AVILA, J. BINA, J. KONRADE, and S. MUNNS. Soft tissue thermodynamics before, during, and after cold pack therapy.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 45–50.BackgroundCold packs are commonly used by clinicians, trainers, and others, often as an interim treatment for many acute conditions, but the extent of temperature change associated with this form of treatment remains poorly understood.MethodsIn 16 healthy male and female volunteers aged 25.4 ± 3.6 yr, we monitored skin temperature, and recorded the temperature of the quadriceps muscle at 1, 2, and 3 cm depths below the skin, before, during, and after 20 min of cold pack treatment.ResultsThe results revealed a slight rise in temperature at all four levels during the 5 min pretreatment period, but significant temperature falls at the skin and 1 cm levels beginning from 8 min of treatment (P< 0.001). There was no significant change in tissue temperature at the 2.0 cm or 3.0 cm depths throughout treatment. However, after treatment, cutaneous temperature and the temperature at 1.0 cm depth rose rapidly, returning to baseline levels at variable intersubject times. As these superficial temperatures rose, there were concurrent falls in the temperatures at the 2.0 cm and 3.0 cm levels. Thus, the deeper tissues lost heat (cooled) simultaneously as the superficial tissues rewarmed; to the extent that 40 min after treatment, the deeper levels were cooler than the cutaneous and 1.0 cm levels.Conclusion1) Cold pack therapy produces significant temperature falls in cutaneous and subcutaneous superficial tissues without directly changing the temperature of tissues at or more than 2.0 cm below the skin; and 2) the temperature gradients of both layers of tissue reverses after treatment, indicating that the deep tissue beneath is at least one of the sources of heat used to rewarm the cooled superficial tissue. The latter finding underscores the importance of the hemodynamic interchange between superficial and deep tissues, and offers an explanation for the reduction of pain, muscle spasm, and edema observed with cold therapy in several clinical situations.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

SARGENT, C., G. C. SCROOP, P. M. NEMETH, R. B. BURNET, and J. D. BUCKLEY. Maximal oxygen uptake and lactate metabolism are normal in chronic fatigue syndrome.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 51–56.PurposePrevious studies in chronic fatigue syndrome (CFS) have reported reductions in maximal oxygen uptake (&OV0312;O2max), yet often the testing procedures have not followed accepted guidelines, and gender data have been pooled. The present study was undertaken to reevaluate exercise capacity in CFS patients by using “gold standard” maximal exercise testing methodology and stratifying results on a gender basis.MethodsSixteen male and 17 female CFS patients and their gender-, age-, and mass-matched sedentary controls performed incremental exercise to volitional exhaustion on a stationary cycle ergometer while selected cardiorespiratory and metabolic variables were measured.Results&OV0312;O2maxin male CFS patients was not different from control values (CFS: 40.5 ± 6.7; controls: 43.3 ± 8.6; mL·kg−1·min−1) and was 96.3 ± 17.9% of the age-predicted value, indicating no functional aerobic impairment (3.7 ± 17.9%). In female CFS patients, &OV0312;O2maxwas lower than control values (CFS: 30.0 ± 4.7; controls: 34.2 ± 5.6; mL·kg−1·min−1,P= 0.002), but controls were higher than the age-predicted value (112.6 ± 15.4%,P= 0.008) whereas the CFS patients were 101.2 ± 20.4%, indicating no functional aerobic impairment (−1.2 ± 20.4%). Maximal heart rate (HRmax) in male CFS patients was lower than their matched controls (CFS: 184 ± 10; controls: 192 ± 12; beats·min−1;P= 0.016) but was 99.1 ± 5.5% of their age-predicted value. In female CFS patients, HRmaxwas not different from controls (CFS: 183 ± 11; controls: 186 ± 10; beats·min−1) and was 98.9 ± 5.1% of the age-predicted value. The &OV0312;O2at the lactate threshold (LT) in each gender group, whether expressed in mL·kg−1·min−1or as a percentage of &OV0312;O2max, was not different between CFS patients and controls.ConclusionsIn contrast to most previous reports, the present study found that &OV0312;O2max, HRmax, and the LT in CFS patients of both genders were not different from the values expected in healthy sedentary individuals of a similar age.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

LEDDY, J. J., A. KESARI, and R. J. SMOLINSKI. Implementation of the Ottawa ankle rule in a university sports medicine center.Med. Sci. Sports Exerc., Vol. 34, No. 1, 2002, pp. 57–62.PurposeThe Ottawa ankle rule (OAR) is a clinical decision rule used in emergency departments to identify which patients with acute ankle/midfoot injury require radiography. The purpose of this study was to implement the OAR, with a modification to improve the specificity for identifying malleolar fractures (the “Buffalo rule”), in a sports medicine center and measure impact on physician practice and cost savings.MethodsAll pediatric and adult patients presenting to a university sports medicine walk-in clinic with acute (≤ 10 d old) ankle/midfoot injury had the rule applied by primary care providers. Exclusion criteria included pregnancy, isolated skin injury, > 10 d since injury, second evaluation for same injury, obvious deformity of ankle or foot, or altered sensorium.ResultsIn 217 patients (mean age, 23.3 ± 8.5 yr; range, 10–64 yr) there were 24 clinically significant (i.e., nonavulsion) fractures (fracture rate 3.7% per year for 3 yr), all of which were identified by the rule (100% sensitivity). In 193 patients with malleolar pain, the sensitivity for malleolar fracture (with 95% confidence intervals) was 100% (78–100%) and specificity was 45% (43–46%). In 24 patients with midfoot pain, sensitivity was 100% (65–100%) and specificity was 35% (21–49%). Thirty-five percent of radiographic series (76 of 217) were foregone for a cost savings of almost $6000. One hundred percent follow-up on those patients for whom x-rays were obtained found no missed fractures and they were subjectively satisfied with their care.ConclusionThe OAR reduced radiography in acute ankle/midfoot injury and saved money in relatively younger patients in the outpatient sports urgent care setting without missing any clinically significant fractures. The specificity of the Buffalo malleolar rule in the present implementation study, however, was not a significant improvement over the OAR malleolar rule. Widespread application of the OAR could save substantial resources without compromising quality of care.

ISSN:0195-9131    

出版商:OVID    

年代:2002

数据来源: OVID