摘要:

Disorders of the patella are the most common cause of anterior knee pain. The etiologies of anterior knee pain are reviewed. A case report of an acute displaced patella fracture in a bipartite union is presented. Bipartite patellar development, incidence, radiographic findings, and clinical symptoms follow. Treatment of excision of displaced fragment provides an excellent result.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Physiological requirements of Alpine skiing, demanding power from both aerobic and anaerobic sources, were first reported in 1965 by Bengt Saltin and coworkers. An update on the physiology of Alpine skiing was presented by Karlsson and colleagues in 1978, and their work remains a benchmark for most current research dealing with Alpine skiers. These works have identified muscular strength and complex motor skill abilities as essential to the competitive ski racer. The energy demands of Alpine ski racing dominate the range between 45 s and 2 min. Since the late 1970s, many researchers have reported a variety of tests that associate test scores to skiing performance. Traditionally, short tests of anaerobic power such as the 30-s Wingate test have been used to reflect anaerobic capacity. Only recently have researchers and coaches begun to question whether a test that is shorter in duration than most skiing performances can estimate anaerobic power as it relates to Alpine ski racing. This study reviews current literature relative to physiological requirements for Alpine skiing as well as relating 18 nationally ranked male (N= 10) and female (N= 8) Alpine ski racers' USSA national points lists for slalom and giant slalom to power measures from 30-s and 90-s Wingate cycle ergometer tests. Further directions of physiological research in Alpine skiing are also offered.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

This brief report describes the physiological demands in competitive Alpine skiing as well as the physiological profile of elite skiers. Maximal heart rate is typically attained by the end of either of the four Alpine ski disciplines. The giant slalom probably calls for the largest reliance upon aerobic energy metabolism and oxygen uptake may increase to 75%-100% of maximal aerobic power. Although high caliber skiers typically show increased maximal aerobic power, it is unlikely that this is an important factor determining success in skiing. Also, anaerobic energy provision accounts for more than half of the total energy yield. Accordingly, plasma and muscle lactate accumulation is substantial after a single race. Similarly, during skiing there is a high rate of glycogen utilization that eventually may result in depletion of muscle glycogen stores by the end of a day of intense skiing. Muscles of Alpine skiers do not posses a distinct fiber type composition and, if anything, skiers tend to show a preponderance of slow twitch fibers. This concords with the recruitment of both muscle fiber types during slalom or giant slalom. Elite skiers show increased knee extensor strength. This seems warranted because there is great reliance upon slow and forceful eccentric muscle actions when performing turns in the giant slalom or slalom.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The purpose of this study was to document and compare the muscular activity patterns observed in seven competitive racers during slalom (SL) and giant slalom (GS) skiing using quantitative parameters of EMG and qualitative video recordings. Twelve muscles of the leg and trunk were monitored using surface electrodes and telemetry. EMG activity was related to phases of movement determined from the video. SL was partitioned into two phases (initiation and turning) and a third phase (completion) was distinguished for GS. The majority of muscles were active at a moderate to high level for the whole turn, with average amplitudes (AA) between 58% and 112% maximum voluntary contraction. Large peak amplitudes (PA) were attributed to the substantial components of centrifugal and gravitational force that the skier must resist in the latter part of the turn. The similarity in muscle activity between SL and GS was surprising. The only significant differences were increases of 11.8% in AA for the AT in SL and 8.8% in PA for the EO in GS. There was ample evidence of co-contraction, suggesting a quasistatic component to skiing.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Balance in Alpine skiing is dynamic and tenuous. Loss of balance typically leads to the accumulation of forces that create severe bending moments at the knee. The modern ski binding, while effective at protecting the ankle and lower leg, is much less effective at protecting the knee. The result: knee injuries have increased nearly threefold since 1972 with anterior cruciate ligament (ACL) injuries currently accounting for approximately 10% of all skiing injuries. The mechanism of ACL injury in elite competitors is distinct from recreational skiers and is typically associated with a characteristic, deeply flexed, seated body position, with the feet accelerating forward relative to the upper body. The risk of ACL injury in elite skiers is compounded by the functional characteristics of the modern ski binding and further exacerbated by the protocols used to set release tension for competition. It is apparent that the physical abilities of the elite competitor, combined with modern ski technique and equipment, expose the skier to forces that the human body cannot tolerate. Presently, the only solution to the problem would appear to be the development of “smarter” bindings and/or the adoption of standards that set limitations on performance for the sake of safety.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Although the overall ski injury incidence continues to decline, knee injuries requiring surgery remain extremely common. Emphasis is placed on the history of the skier's fall in making an accurate diagnosis. This injury pattern is then assessed with the skier's age and activity level in determining the most appropriate surgical procedure. The actual surgical intervention is just a portion of the rehabilitation process in returning a skier back to sport as quickly as possible. The most common injuries requiring surgical intervention include meniscal tears, osteochondral fractures, and ligament tears. Our indications and techniques are described. Early focus on postoperative range of motion is emphasized. Strengthening begins only when full, pain-free range of motion is obtained. Utilizing these principles, our goals have been to complete the rehabilitation process coexistent with healing of the injury.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

For preventive purposes habitual physical activity was investigated in noninstitutionalized elderly and a profile was composed of the most inactive among them. In a cross-sectional study conducted in 1992 in Arnhem, 503 women and 493 men, aged 65–84 yr, were interviewed. Habitual physical activities and total activity scores were assessed with a questionnaire, previously validated for elderly. Among other things, our findings revealed that light housework (e.g. dusting, washing dishes) was carried out by 90% of the women and 61% of the men. Thirteen percent of the women and 9% of the men had no recreational physical activities (sports or other physically active leisure time activities). Physical activity level seems to be associated with age, socioeconomic status (only for men), marital status (only for women), disability, subjective health, presence of chronic diseases, living in houses with stairs, and living close to shops (only for men). For example, age-adjusted odds ratios for being physically inactive were 28.6 and 7.1, respectively, for women and men with disabilities (95% confidence intervals: 6.4–127.0 and 2.7–18.3, respectively). Our findings suggest physically inactive elderly are mainly characterized by older age and a less favorable health. Physical activity of these elderly deserves special attention, to prevent further deterioration and loss of independence.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The relationships between physical activity, physical fitness, and coronary heart disease risk factors measured in a large community sample were evaluated. Self-reported physical activity using a single question, maximal oxygen consumption estimates derived from the Pawtucket Heart Health Step Test, blood pressure, nonfasting lipids, and body mass index were cross-sectionally evaluated in 381 men and 556 women. The correlation of estimated maximal oxygen consumption and self-reported physical activity was modest but statistically significant (r = 0.13 in men and r = 0.19 in women). Blood pressure, body mass index, and HDL cholesterol were correlated with physical fitness (r = 0.24–0.65) and correlated to self-reported physical activity (r = 0.09–0.14). Evaluation of coronary heart disease risk factors using both physical activity and physical fitness revealed a complex relationship that generally showed a stronger relationship with measures of physical fitness than with physical activity. This study suggests that simultaneous measurement of physical activity and physical fitness may be useful in epidemiologic studies of habitual physical activity and chronic disease.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

The 24-h energy expenditure (24-h EE), resting EE (REE), sleeping EE (SEE), and spontaneous physical activity (SPA) were compared between six male endurance athletes whose reported energy intake was low (LOW) and did not match that theoretically required for weight maintenance and four whose reported energy intake appeared adequate (ADQ) and matched their estimated EE. Groups did not differ in age, body weight, fat-free mass, and daily EE estimated from activity records. The LOW athletes reported an energy intake 6338 ± 2164 kJ·d−1less than estimated EE. The 24-h EE, REE, SEE, and SPA of the LOW athletes were significantly lower than the ADQ athletes (862, 523, 770 kJ·d−1, and 43 min·d−1, respectively). Using all subjects, there was a significant positive correlation between REE and free thyroxine (FT4) (r = 0.82) and SEE and FT4(r = 0.66). Thus, part of the LOW athlete's ability to maintain body weight on a seemingly low energy intake appears due to a lower daily sedentary EE.

ISSN:0195-9131    

出版商:OVID    

年代:1995

数据来源: OVID