Showing papers by "Jan Ekstrand published in 1983"

Soccer injuries and their mechanisms: a prospective study.

Abstract: In order to study the incidence and mechanisms of injury in soccer and to recommend prophylactic measures, 180 players in a senior male soccer division were followed prospectively for 1 yr. Attendance records for games and practice sessions were kept, and all injuries were examined and treated by the same orthopaedic surgeon. One hundred twenty-four players incurred 256 injuries, mostly sprains and strains of the lower extremities. Of these, 62% were considered minor with ankle sprains being the most common (17%), while 11% were considered major with knee ligament sprains being the most frequent (32%). Overuse injuries were most frequent in the preseason training period. Traumatic leg injuries involved players with inadequate or no shin guards. Of the traumatic knee injuries, 11 of 18 (61%) occurred during a collision; non-contact knee injuries were frequently seen in those players with a history of knee injury and existing instability. Study of injury sequence disclosed that a minor injury was often followed within two months by a major one. In addition, with severe injuries incurred during fouls, the individual causing the penalty was injured. This prospective study suggested that those with knee instability and those allowed to resume play with poorly rehabilitated or clinically unhealed injuries are more apt to sustain further injury. Some injuries can be avoided by using better equipment and by observance of the rules.

The Avoidability of Soccer Injuries

Abstract: One hundred eighty players in a male soccer division were followed prospectively for 1 year to assess etiologic factors in soccer injuries. Range of motion and muscle strength in the lower extremities were measured in a preseason test. All injuries during 1 year were examined by the same orthopaedic surgeon. 42% of the injuries were considered to be due to player factors, such as joint instability, muscle tightness, inadequate rehabilitation, or lack of training. Ankle sprains were commoner in players with previous ankle sprains or clinical instability. 35% of the moderate (absence from practice greater than 1 week, less than 1 month) or major (absence greater than 1 month) injuries were preceded by minor (absence less than 1 week) injuries, reflecting inadequate rehabilitation. Players sustaining knee sprains not due to collision had reduced muscle strength in the injured leg. No other strength differences between injured and uninjured players were found. 63% of players had tight muscles. Strains more commonly affected players with muscle tightness. 71% of the injuries proved to be explicable by and associated with player factors, equipment, playing ground, or rules.

Prevention of soccer injuries Supervision by doctor and physiotherapist

Abstract: To study the efficacy of an injury prevention program in a randomized trial, 12 teams (180 players) in a male senior soccer division were followed up for 6 months. The 12 teams were allocated at random to two groups of six teams, one being given a prophylactic program and the other serving as control. The program was based on previous studies of injury mechanisms. It comprised (1) correction of training, (2) provision of optimum equipment; (3) prophylactic ankle taping; (4) controlled rehabilitation; (5) exclusion of players with grave knee instability; (6) information about the importance of disciplined play and the increased risk of injury at training camps; and (7) correction and supervision by doctor(s) and physiotherapist(s). The injuries in the test teams were 75% fewer than in the controls. The most common types of soccer injuries, sprains and strains to ankles and knees, were all significantly reduced. It is concluded that the proposed prophylactic program, including close supervision and correction by doctors and physiotherapists, significantly reduces soccer injuries.

Incidence of soccer injuries and their relation to training and team success.

Abstract: One hundred-eighty players in a male soccer senior division of 12 teams were observed prospectively for 1 year to study the risk of soccer injuries in relation to exposure and to establish the connection between training, injuries, and team success. Totally, more than 100 hours of practice were analyzed. All injuries were examined by the same orthopaedic surgeon. On the average, each team played 36 games and had 95 practice sessions with 66% attendance of selected players. A direct correlation was noted between team success and the amount of training. Teams with more than average training showed a diminishing number of injuries. A high practice-to-game ratio seems to be advantageous. One injury every third game and every ninth practice session was documented. For the individual player the incidence of injury was 7.6/1000 practice hours and 16.9/1000 game hours. The incidence of injury was higher at training camps. Correlation was noted between the design of the training and the incidence of injuries. The duration of warming up seemed adequate, but its content did not appear to be satisfactory from a clinical point of view. Redesign of the warm-up with more emphasis on flexibility and the addition of a cool-down is suggested to reduce injuries.

Effects of warming up, massage, and stretching on range of motion and muscle strength in the lower extremity

Abstract: The effects of general warming up, massage, and stretching on ranges of motion (ROM) and strength of quadriceps and hamstring muscles were measured in eight male volunteers. Thigh muscle strength was not influenced by the experimental procedures. Stretching resulted in a significantly increased range of hip flexion/extension, hip abduction, knee flexion, and ankle dorsiflexion; the effect was significantly greater than that obtained by massage and warming up separately or combined. Only ankle dorsiflexion was influenced by massage or warming up, whereas stretching affected all muscle groups tested. Stretching was, therefore, superior to the other methods tested for increasing flexibility in the lower extremity.

Plasma fluoride concentrations in pre-school children after ingestion of fluoride tablets and toothpaste.

Abstract: Plasma fluoride (F) concentration and urinary F excretion were studied in 5 children, age 3–4 years, after intake of F tablets (0.5 mg) and 0.6 g of two NaF toothpastes containing 0.1 and 0.025% F – c

The relationship between plasma fluoride, urinary excretion rate and urine fluoride concentration in man

Abstract: The fluoride concentration in urine is commonly used for monitoring fluoride exposure, e.g., in aluminium plants. Hitherto this parameter does not seem to have been related to the actual fluoride concentration in plasma following fluoride exposure. In the present study the fluoride concentration in urine, the urinary excretion rate of fluoride and the fluoride concentration in plasma have been studied in five volunteers after intake of 10 mg of fluoride in the form of sodium fluoride (NaF) tablets. In pharmacokinetic analyses of the data calculation of the half-life of fluoride from plasma data and from the urinary excretion rate yielded almost identical results; 5.78 hours (plasma) and 5.11 hours (urine). It was found that plasma fluoride levels were correlated with the fluoride concentration in urine (r = .7532; n = 70), but even more with the urinary excretion rate of fluoride (r = .9651; n = 63). The data suggest that plasma fluoride levels or urinary excretion rates of fluoride may give a more correct picture of occupational fluoride exposure than fluoride concentrations in urine.

Determination of fluoride in biological fluids with a reversible solid-state contact combination fluoride electrode

Abstract: Solid-state combination potentiometric sensors with integrated impedance transformation microelectronics, containing two chemically “orthogonal” ion-selective membranes, LaF3 and AgS/AgI, have been constructed and tested in the practical analysis of fluoride in human blood plasma and spinal fluid. The results obtained with this electrode compared favourably with those obtained with conventional electrodes. The response time for the new electrode in the range of 10−6 M was between 5–10 min. Because of its rapid response and high sensitivity the reversible solid-state fluoride electrode is suitable for fluoride analyses of biological fluids.

Cyclic AMP in Urine, Kidney and Liver Following Long‐term Administration of Fluoride to Rats

Abstract: Rats were exposed to fluoride (F) for up to 8 weeks through the drinking water containing 100 p.p.m. F. Urine samples were regularly collected, together with tissue samples of liver and kidney at termination. All samples were assayed for cyclic AMP. No F-effect was found on liver or kidney levels of cyclic AMP. In the urine from the F-exposed rats there was an overall increase in the cyclic AMP concentration, but a decreased or unaffected 24 hrs urinary excretion of cyclic AMP. However, the F-exposed rats exhibited a considerably lower diuresis than the control animals. Because a significant negative correlation was found between diuresis and urinary concentration of cyclic AMP, the material was corrected to similarity in the mean diuresis between the two groups. Then no effect of F-exposure could be detected either in the urinary concentration or the daily excretion of cyclic AMP.