Soccer

Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than male athletes. The underlying cause of ACL injury is multifactorial. However, several researchers have identified knee joint laxity as a possible contributing factor. The purpose of this study was to provide a comparison of knee joint laxity between male and female collegiate soccer players and male and female non‐athletes. Thirty‐nine (19 male, 20 female) apparently healthy, collegiate athletes from the University of Texas at El Paso's 2001‐2002 women's intercollegiate soccer team and men's club soccer team, and forty (20 male, 20 female) non‐athletic students volunteered to participate. All participants were tested bilaterally using the KT‐1000 MEDmetric knee joint ligament arthrometer. Three tests were used to determine anterior laxity: passive displacement, active displacement, and the Lachman test. The mean passive displacement, mean active displacement, and Lachman (only for the left leg) were significantly lower for the athletic group than for the non‐athletic group. There were no significant differences found between males and females for the passive and active drawer tests. However, females had significantly more laxity than males in the Lachman test. These findings suggest that strength and conditioning may play a more significant role in knee joint laxity than the sex of the individual.     

Effect of attending to a ball during a side-cut maneuver on lower extremity biomechanics in male and female athletes

Many sports associated with anterior cruciate ligament (ACL) injury require athletes attend to a ball during participation. We investigated effects of attending to a ball on lower extremity mechanics during a side-cut maneuver and if these effects are consistent for males and females. Sagittal and frontal plane hip and knee kinematics and joint moments were measured during side-cut maneuvers in 19 male and 19 female National Collegiate Athletic Association division III basketball players. Participants also experienced two side-cut conditions that required attention to a ball. Our results did not indicate that the effect of attention varies with gender. However, during side-cut conditions while attending to a ball, internal knee adductor moment was 20% greater (p = 0.03) and peak knee flexion angle was 4 degrees larger (p < 0.01). Females demonstrated 5 degrees less hip flexion (p = 0.046), 12 degrees less knee flexion (p < 0.01), and 4 degrees more knee abduction (p = 0.026) at initial contact during all side-cut conditions than males. Attention to a ball may affect lower extremity mechanics relevant to ACL injury. The validity of laboratory studies of lower extremity mechanics for sports that include attention to a ball may be increased if participants are required to attend to a ball during the task.     

Effects of neuromuscular fatigue on perceptual-cognitive skills between genders in the contribution to the knee joint loading during side-stepping tasks

This study investigated whether neuromuscular fatigue affects the neuromuscular control of an athlete within a sports context setting and whether these effects were more pronounced in the females. Lower limb joint kinetics of 6 male and 6 female inter-varsity soccer players performing side-stepping tasks in non-fatigue versus fatigue and anticipated versus unanticipated conditions were quantified using 10 Motion Analysis Corporation cameras and a Kistler^? force platform. The Yo-Yo intermittent recovery Level 1 fatigue protocol was employed. Stance foot initial contact and peak forces, and peak joint knee moments of the lower limb were submitted to a 3-way mixed-model repeated measure ANOVA. The results suggested that males tend to elicit significantly higher knee joint loadings when fatigued. In addition, males elicited significantly higher peak proximal tibia anterior/posterior shear force, vertical ground reaction force at initial contact and peak internal rotational moments than females. These findings suggested that males were at greater overall injury risk than females, especially in the sagittal plane. Neuromuscular control-based training programmes/interventions that are designed to reduce the risk of the non-contact ACL injury need to be customised for the different genders.     

Gender differences in lower limb frontal plane kinematics during landing

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.     

Gender differences in lower limb frontal plane kinematics during landing

The aim of this study was to investigate gender differences in knee valgus angle and inter-knee and inter-ankle distances in university volleyball players when performing opposed block jump landings. Six female and six male university volleyball players performed three dynamic trials each for which they were instructed to jump up and block a volleyball suspended above a net set at the height of a standard volleyball net as it was spiked against them by an opposing player. Knee valgus/varus, inter-knee distance, and inter-ankle distance (absolute and relative to height) were determined during landing using three-dimensional motion analysis. Females displayed significantly greater maximum valgus angle and range of motion than males. This may increase the risk of ligament strain in females compared with males. Minimum absolute inter-knee distance was significantly smaller, and absolute and relative inter-knee displacement during landing significantly greater, in females than males. Both absolute and relative inter-ankle displacement during landing was significantly greater in males than females. These findings suggest that the gender difference in the valgus angle of the knee during two-footed landing is influenced by gender differences in the linear movement of the ankles as well as the knees. Coaches should therefore develop training programmes to focus on movement of both the knee and ankle joints in the frontal plane in order to reduce the knee valgus angle during landing, which in turn may reduce the risk of non-contact anterior cruciate ligament injury.     

Influence of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres

Limb dominance theory suggests that females tend to be more one-leg dominant and exhibit greater kinematic and kinetic leg asymmetries than their male counterparts, contributing to the increased risk of anterior cruciate ligament injury among female athletes. Thus, the purpose of this study was to examine the influences of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres. Twenty-one women and 21 men completed land-and-cut manoeuvres on their dominant limb as well as their nondominant limb. Three-dimensional kinematics and kinetics were calculated bilaterally for the entire stance phase of the manoeuvre. Women performed land-and-cut manoeuvres with altered hip motions and loads as well as greater knee abduction at touchdown compared to men. Dominant limb land-and-cut manoeuvres where characterised by decreased hip flexion at touchdown as well as decreased hip flexion and adduction range of motion compared to nondominant land-and-cuts regardless of sex. The observed sex differences are consistent with previous research regarding mechanisms underlying the sex disparity in anterior cruciate ligament injury rates. However, observed differences regarding limb dominances appear somewhat arbitrary and did not suggest that the dominant or nondominant limb would be at increased risk of anterior cruciate ligament injury.     

Effect of attending to a ball during a side-cut maneuver on lower extremity biomechanics in male and female athletes

Many sports associated with anterior cruciate ligament (ACL) injury require athletes attend to a ball during participation. We investigated effects of attending to a ball on lower extremity mechanics during a side-cut maneuver and if these effects are consistent for males and females. Sagittal and frontal plane hip and knee kinematics and joint moments were measured during side-cut maneuvers in 19 male and 19 female National Collegiate Athletic Association division III basketball players. Participants also experienced two side-cut conditions that required attention to a ball. Our results did not indicate that the effect of attention varies with gender. However, during side-cut conditions while attending to a ball, internal knee adductor moment was 20% greater (p = 0.03) and peak knee flexion angle was 4° larger (p < 0.01). Females demonstrated 5° less hip flexion (p = 0.046), 12° less knee flexion (p < 0.01), and 4° more knee abduction (p = 0.026) at initial contact during all side-cut conditions than males. Attention to a ball may affect lower extremity mechanics relevant to ACL injury. The validity of laboratory studies of lower extremity mechanics for sports that include attention to a ball may be increased if participants are required to attend to a ball during the task.     

Sport injuries as the main cause of sport career termination among Finnish top-level athletes

Abstract

Injuries are common among athletes, and are sometimes so severe that they affect an athlete's career in sport. As studies on sport career termination are few, we conducted a study to investigate the role of injuries as a reason for ending a sport career. The study group consisted of 574 male and female top-level cross-country skiers, swimmers, long-distance runners and soccer players who responded to a retrospective postal questionnaire in 2006. Twenty-seven athletes (4.9%, 27/548) reported ending their sport career because of injury. A follow-up interview was conducted by telephone in 2007 (n=20 volunteered to be interviewed) to confirm sport career termination and the reasons for this. Fifteen of the interviewed athletes terminated and five continued their sport on the same level as earlier. Female athletes (12/15) terminated their sport career more frequently than male athletes (3/15). Athletes who reported terminating their sport career because of injury were on average two and a half years older (24.1 years vs. 21.6 years, P=0.006) than athletes who continued the sport. All the swimmers (n=5) who were interviewed terminated their career because of a shoulder injury. All the soccer players who ended their career (n=4) were female and had a severe knee injury, such as anterior cruciate ligament injury. Most of the athletes who terminated their sport career (70.4%, 19/27) reported that the injury caused them mild or moderate permanent disability. We found that sports injuries play a significant role in terminating a career in sport, and in some sports events injuries may commonly be the main reason for sport career termination. Injury prevention and adequate treatment and rehabilitation of injuries are thus essential to avoid the long-term consequences of severe sport injuries.     

Relationship between three-dimensional kinematics of knee and trunk motion during shuttle run cutting

Female athletes are considered to exhibit knee and trunk motion that is characteristic of anterior cruciate ligament (ACL) injury. The aim of this study was to examine the in vivo motion of the trunk and knee during a cutting manoeuvre and determine the relationship between them. All participants (10 male and 10 female college athletes) performed a shuttle run cutting task with the left limb. Trunk inclination (forward and lateral) and knee joint angles (flexion/extension, abduction/adduction, and internal/external tibial rotation) were calculated. Differences between the sexes and associations between knee motion and trunk inclination were examined. An increase in trunk forward inclination was strongly correlated with an increase in knee flexion angle and moderately correlated with a decrease in the excursion of internal tibial rotation. An increase in right trunk lateral inclination was moderately correlated with an increase in excursion of internal tibial rotation. The results also showed differences between the sexes in trunk forward inclination, lateral inclination, and knee flexion angle, but no such differences in knee abduction or internal tibial rotation. Trunk inclination is related to knee flexion and excursion of internal tibial rotation. Female athletes demonstrate a low trunk forward inclination and knee flexion angle, a posture that resembles that of ACL injury.     

我国高山滑雪运动员膝关节运动损伤的调查分析

文章对我国高山滑雪运动员膝关节运动损伤情况进行调查分析,结果表明：在高山滑雪运动中,膝关节损伤是最常见的损伤,其损伤部位主要是前交叉韧带、滑囊炎、髌骨劳损、半月板损伤和侧副韧带损伤。旨在引起在高山滑雪教学、训练、比赛时减少膝关节损伤及其预防的重视,使运动员尽量减少和避免膝关节运动损伤的发生,进而延长运动寿命,提高训练效果,维护及稳定运动成绩。     

Ground reaction forces and kinematics of plant leg position during instep kicking in male and female collegiate soccer players

The players' ability to achieve the greatest distance in kicking is determined by their efficiency in transferring kinetic energy from the body to the ball. The purpose of this study was to compare the kinetics and kinematics of the plant leg position between male and female collegiate soccer players during instep kicking. Twenty-three soccer players (11 males and 12 females) were filmed in both the sagittal and posterior views while performing a maximal instep kick. Plant leg kinetic data were also collected using an AMTI 1000 force platform. There were no significant differences between the sexes in plant leg position, but females had significantly greater trunk lean, plant leg angle, and medial-lateral ground reaction force than the males. Males showed higher vertical ground reaction forces at ball contact, but there were no significant differences in ball speed at take-off between the sexes. Ball speed at take-off was inversely related to peak anterior–posterior ground reaction force ( ? 0.65). The anatomical differences between the sexes were reflected in greater trunk lean and lower leg angle in the females.     

Frontal plane comparison between drop jump and vertical jump: implications for the assessment of ACL risk of injury

The potential to use the vertical jump (VJ) to assess both athletic performance and risk of anterior cruciate ligament (ACL) injury could have widespread clinical implications since VJ is broadly used in high school, university, and professional sport settings. Although drop jump (DJ) and VJ observationally exhibit similar lower extremity mechanics, the extent to which VJ can also be used as screening tool for ACL injury risk has not been assessed. This study evaluated whether individuals exhibit similar knee joint frontal plane kinematic and kinetic patterns when performing VJs compared with DJs. Twenty-eight female collegiate athletes performed DJs and VJs. Paired t-tests indicated that peak knee valgus angles did not differ significantly between tasks (p = 0.419); however, peak knee internal adductor moments were significantly larger during the DJ vs. VJ (p < 0.001). Pearson correlations between the DJ and VJ revealed strong correlations for knee valgus angles (r = 0.93, p < 0.001) and for internal knee adductor moments (r = 0.82, p < 0.001). Our results provide grounds for investigating whether frontal plane knee mechanics during VJ can predict ACL injuries and thus can be used as an effective tool for the assessment of risk of ACL injury in female athletes.     

Relationship between three-dimensional kinematics of knee and trunk motion during shuttle run cutting

Abstract

Female athletes are considered to exhibit knee and trunk motion that is characteristic of anterior cruciate ligament (ACL) injury. The aim of this study was to examine the in vivo motion of the trunk and knee during a cutting manoeuvre and determine the relationship between them. All participants (10 male and 10 female college athletes) performed a shuttle run cutting task with the left limb. Trunk inclination (forward and lateral) and knee joint angles (flexion/extension, abduction/adduction, and internal/external tibial rotation) were calculated. Differences between the sexes and associations between knee motion and trunk inclination were examined. An increase in trunk forward inclination was strongly correlated with an increase in knee flexion angle and moderately correlated with a decrease in the excursion of internal tibial rotation. An increase in right trunk lateral inclination was moderately correlated with an increase in excursion of internal tibial rotation. The results also showed differences between the sexes in trunk forward inclination, lateral inclination, and knee flexion angle, but no such differences in knee abduction or internal tibial rotation. Trunk inclination is related to knee flexion and excursion of internal tibial rotation. Female athletes demonstrate a low trunk forward inclination and knee flexion angle, a posture that resembles that of ACL injury.     

国家队激流回旋运动员肩关节脱位的分析研究

通过对国家队激流回旋运动员损伤状况的检查和治疗发现 ,肩关节脱位发生率比较高 ,女性高于男性 ;肩关节脱位与肩周围软组织损伤密切相关 ;“爱斯基摩翻滚”是导致肩关节脱位的主要技术动作。据此 ,提出了 4项建议     

运动员前交叉韧带损伤的流行病学研究

１９９１年８月￣１９９３年９月对国家,省,市级等４７个人共６８１０名运动员进行了运动创伤流行病学调查,其中ＡＣＬ损伤３２例,癖发病率为０．４７％,损伤病因中技术失误伤首位,为５９．４％,上外与损伤（１５．６％）,场地（３．１％）等因素有关,全部病例均有不同程度的膝关节症状。尽管有３１％的人可参加正常训练,但５３．６％的同受到不同程度的影响,有些不得以停训或手术治疗。本文对ＡＣＬ损伤的致伤因素,诊断     

A functional agility short-term fatigue protocol changes lower extremity mechanics

The purpose of this study was to evaluate the effects of a functional agility fatigue protocol on lower extremity biomechanics between two unanticipated tasks (stop-jump and sidestep). The subjects consisted of fifteen female collegiate soccer athletes (19±0.7 years, 1.67±0.1 m, 61.7±8 kg) free of lower extremity injury. Participants performed five trials of stop-jump and sidestep tasks. A functional short-term agility protocol was performed, and immediately following participants repeated the unanticipated running tasks. Lower extremity kinematic and kinetic values were obtained pre and post fatigue. Repeated measures analyses of variance were conducted for each dependent variable with an alpha level set at 0.05. Knee position post-fatigue had increased knee internal rotation (11.4±7.5° vs. 7.9±6.5° p=0.011) than pre-fatigue, and a decreased knee flexion angle (-36.6±6.2° vs. ?40.0±6.3°, p = 0.003), as well as hip position post-fatigue had decreased hip flexion angle (35.5±8.7° vs. 43.2±9.5°, p = 0.002). A quick functional fatigue protocol altered lower extremity mechanics of Division I collegiate soccer athletes during landing tasks. Proper mechanics should be emphasized from the beginning of practice/game to aid in potentially minimizing the effects of fatigue in lower extremity mechanics.     

Whole-body control of anticipated and unanticipated sidestep manoeuvres in female and male team sport athletes

ABSTRACT

The purpose of this study was to investigate the influence of sex and planning time on spatial and temporal aspects of the whole-body centre of mass (CoM) mechanics during sidestepping performance. Seventeen female and 17 male collegiate team sport athletes completed seven anticipated and seven unanticipated sidestep trials during which three-dimensional CoM data were recorded. Female athletes had a reduced ability to reorient their CoM towards the desired direction of travel (lower medio-lateral and anterior-posterior CoM velocity) than their male counterparts, with reduced medial (closer to stance foot) and increased posterior positioning of CoM relative to the stance foot (p < 0.05). When planning time was limited, female and male athletes performed sidestepping with CoM further from the stance foot (more medial) and more anterior than in the anticipated condition (p < 0.05) at reduced medio-lateral velocities. Sex and condition control strategy differences were evident both in the preparatory phase and the stance phase. The current research draws attention to the foreseen benefits of training athletes, with particular emphasis on females, to direct CoM towards the desired direction of travel in the preparatory and stance phases within temporally constrained situations for improved performance.     

The quantification of joint laxity in dancers and gymnasts

The aim of this study was to determine the range of movement in gymnastic and dance populations. Sixty-five participants (41 females, 24 males; mean age 21.4 years) were assessed. The sample included dancers and gymnasts ranging from novice and club standard to international and professional status. Non-specialized physical education students acted as controls. Range of movement was measured at the shoulders, hips, lumbar spine and ankles using a Loebl hydrogoniometer, and inherent joint laxity was assessed using Beighton and coworkers' adaptation of the Carter and Wilkinson 9-point scale. The right and left sides of the body were assessed and measures of active and passive motion were recorded. A graded increase in laxity was observed from controls, through novice gymnasts, to dancers and finally international gymnasts. The greater laxity of females than males was also confirmed. Dancers and gymnasts had a greater passive range of movement in all joints, which was partly inherited and partly acquired. There was a large difference between their active and passive ranges, which appeared to render the joints unstable.     

The quantification of joint laxity in dancers and gymnasts.

The aim of this study was to determine the range of movement in gymnastic and dance populations. Sixty-five participants (41 females, 24 males; mean age 21.4 years) were assessed. The sample included dancers and gymnasts ranging from novice and club standard to international and professional status. Non-specialized physical education students acted as controls. Range of movement was measured at the shoulders, hips, lumbar spine and ankles using a Loebl hydrogoniometer, and inherent joint laxity was assessed using Beighton and coworkers' adaptation of the Carter and Wilkinson 9-point scale. The right and left sides of the body were assessed and measures of active and passive motion were recorded. A graded increase in laxity was observed from controls, through novice gymnasts, to dancers and finally international gymnasts. The greater laxity of females than males was also confirmed. Dancers and gymnasts had a greater passive range of movement in all joints, which was partly inherited and partly acquired. There was a large difference between their active and passive ranges, which appeared to render the joints unstable.