ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We endeavored to clarify the role of the shoulder girdle during the backstroke. Twelve muscles of the shoulder girdle in competitive swimmers with normal shoulders were studied with fine-wire electromyography (EMG). The results demonstrated a similar pattern of activation at hand entry and hand exit in the three heads of the deltoid, supraspinatus, and scapular rotators as they positioned the shoulder girdle for hand entry and exit. The latissimus dorsi, subscapularis, and teres minor were the primary muscles during the propulsive phase. The pectoralis major and infraspinatus revealed minimal activation throughout the stroke.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We discuss the importance of a specific strengthening program for the rotator cuff muscles in the competitive backstroke swimmer. The muscle firing pattern of 12 shoulder-girdle muscles was compared in painful and normal shoulders of competitive swimmers doing the backstroke. The key findings showed that the supraspinatus, teres minor, and subscapularis decreased their firing during pull-through in swimmers with painful shoulders, which was most likely due to impingement. At the same time, the latissimus dorsi and pectoralis major increased their activity in order to compensate for the rotator cuff and depress the humeral head.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Patellofemoral congruity was analyzed using magnetic resonance imaging (MRI) in 54 women (10 normal knees, 10 with patellar chondromalacia, 14 with patellar subluxation, and 20 with patellar dislocation). The patellofemoral joints were imaged both sagittally and axially with the muscles relaxed and with the knee positioned in 0°, 10°, 20°, and 30° of flexion. The axial images were aligned through the midpoint of the patellar articular cartilage, and an index relating the position of the patella to the underlying lateral femoral condyle was measured. When the index was measured from images produced in knee extension (0°), the index significantly differentiated all the study groups from controls. In 20° and 30° of knee flexion, the differences between the groups were no longer as pronounced as in 0° and 10° of knee flexion. In knee extension, an index value

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Because of its easy access, tympanic membrane temperature has enjoyed increasing popularity as an index of deep core temperature during exercise as well as during recovery from exercise. These measurements are made with the assumption that changes in tympanic membrane temperature reflect changes in deep body temperature and, therefore, can be used as an index for the treatment of hyperthermia. In the present study, we report measurements of tympanic, esophageal and skin temperature in subjects exercising at constant (n = 6) or incremental (n = 4) work loads, and during recovery from exercise. Fanning of the upper chest was applied during recovery in two of the subjects who repeated the constant load exercise. Tympanic temperature was lower than esophageal during constant and incremental load exercise (p< 0.025 andp< 0.05, respectively). For both constant and incremental load exercise, there was a delay in the increase in tympanic temperature and the magnitude of the change was less than that of esophageal temperature. Furthermore, during recovery from steady state exercise, while tympanic and skin temperatures still increased, esophageal temperature readily decreased. Finally, because fanning influenced both tympanic and skin temperature changes and had little effect on esophageal temperature, we conclude that tympanic membrane temperature is influenced by rapid changes in skin temperature and should not be used to assess the thermal state of athletes during exercise or during recovery from exercise.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

We reviewed retrospectively the results of knee arthroscopy in 23 patients (28 knees), 60 years and older. The majority of knees (71%) were initially evaluated at the Division of Sports Medicine because of symptoms attributed to a recent or past injury, and most had specific symptoms such as localized pain (64%), swelling (29%), locking (18%), catching (11%), or giving way (11%). Radiographic evidence of osteoarthritis, usually mild, was present in 63% of knees. Arthroscopy was performed when specific physical findings were suggestive of internal derangement in knees without radiographic evidence of severe degenerative disease. Partial meniscectomy was performed for tears of the medial and lateral meniscus in 75 and 43% of knees, respectively: six knees (21%) had tears of both medial and lateral menisci. Other procedures performed included shaving of chondromalacia patellae (18%) and removal of loose body (7%). At average follow-up 19 ± 13 months (range 2–36 months) after surgery in 17 of the 28 knees, most knees had significant improvement of pain (88%) and function (88%) compared with preoperative status. Further surgery was only rarely required. In older patients, arthroscopy of the knee is useful for the diagnosis and treatment of internal derangements, and results are satisfactory if severe osteoarthritis is not present.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The purpose of this study was to evaluate the long-term results of surgery for chronic Achilles tendinitis. Twenty-seven competitive athletes (average age 32, range 17–56 years) and 21 noncompetitive athletes (average age 40, range 20–65 years) were studied. The average duration of preoperative symptoms was 2.7 years (range 0.25–14 years) for the competitive athletes and 4.0 years (range 0.5–27 years) for the noncompetitive athletes. In all cases, conservative treatment failed as assessed by severity of pain and extent of disability. Surgical procedures included: tenolysis (A), n = 20; tenolysis, excision of the posterior aspect of the os calcis, and the retrocalcaneal bursa (B), n = 25; and tenolysis and excision of the retrocalcaneal bursa only (C), n = 3. The average length of follow-up for all groups was 52 months (range 15–96 months). The criteria for assessment of recovery were based on the degree to which the patients were able to return to their preinjury activity level. Where there was a complete absence of pain, the result was considered excellent. Where occasional but minor symptoms persisted, the result was termed good. Using these criteria, procedure A was associated with a 95% success rate while procedures B and C (pooled because of small n) were associated with a 93% success rate. The average time for all patients to return to their preinjury level of activity was 22 ± 12 weeks following procedure A, 29 ± 16 weeks following procedure B, and 32 ± 19 weeks following procedure C. The time to “full activity” for all patients was significantly, (p< 0.05), longer following procedure B compared with procedure A. The recovery times following procedure A were significantly, (p< 0.05), longer for noncompetitive compared with competitive athletes. Ten patients did not return to their previous level of activity, four because of persistent heel pain and six due to other reasons. We conclude that surgery for chronic Achilles tendinitis is efficacious in recalcitrant cases but the choice of surgical procedure affects the time to recovery.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The influence of peripheral arterial insufficiency and severe exercise on muscle mass, capillarity and mitochondrial content was analyzed in rat extensor digitorum (EDL) muscles. Animals (n = 4) were assigned to three groups: ligation of the common iliac artery, chronic electrical stimulation (10 Hz, 6 h/day) of the peroneal nerve, and a combination of both. All interventions were carried out unilaterally, animals were treated for 10–12 days. The effects of the experimental procedures were judged by a paired analysis of treated muscles to contralateral untreated muscles of the same animals. Ligation of the common iliac artery alone had no effect on the quantitative structural composition of the EDL muscle. If ischemia was combined with electrical stimulation, a massive reduction in muscle mass occurred. However, as a consequence of an increase in mitochondrial and capillary density, the total mitochondrial volume and the total capillary length was maintained in these muscles. Stimulated ischemic muscles thus had improved conditions for aerobic energy supply for the remaining reduced myofibrillar apparatus. Extensive swelling of capillary endothelial cells was observed in stimulated as well as in contralateral muscles of all animals that received electrical stimulation. It is concluded that severe exercise may lead to extensive damage in ischemic skeletal muscles.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

A training stimulus can be effective only if intensity and duration of the training workload correspond to the present individual workload capacity. On this narrow strait between training below an effective threshold on the one hand and overtraining on the other, sports medicine has different blood parameters at its disposal, which we discuss in this paper.

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

The present article reviews the energy needs of the soccer player and the potential contribution of carbohydrate to meeting these needs. During a typical match, high-level players cover ∼ 10 km by a combination of sprinting, jogging, and walking. High intensity activity occupies 8–12% of playing time. The distance that is covered provides a minimum estimate of energy needs (3–4 MJ/game), since the energy cost of play is increased relative to the treadmill by such factors as rough ground and frequent stops and starts. The average heart rate implies usage of ∼ 75% of maximal oxygen intake, or 6–7 MJ/game, but this value is commonly biased upwards by the excitement of competition and thermal effects. Direct measurements of oxygen consumption support a value midway between these estimates (5 MJ/game). The main immediate source of energy for sprints and decelerations is local phosphagen, but resynthesis is heavily dependent upon carbohydrate metabolism, both anaerobic and aerobic. During a match, there is a 50% depletion of carbohydrate reserves in the leg muscles, sometimes with a substantial fall of blood glucose. As in some other team sports, maintenance of high quality performance depends on success in conserving carbohydrate. Nutritional implications are that pregame carbohydrate reserves be built up by a high carbohydrate diet, and dilute sugar solutions be provided at halftime (without raising osmolality to a level where fluid intake is impaired).

ISSN:1050-642X    

出版商:OVID    

年代:1992

数据来源: OVID