1. Olsen OE , Myklebust G , Engebretsen L , Bahr R . Injury mechanisms for anterior cruciate ligament injuries in team handball: a systematic video analysis . Am J Sports Med . 2004 ; 32 ( 4 ): 1002 – 1012 . PubMed ID: 15150050 doi:10.1177/0363546503261724 10
Shelby A. Peel, Lauren E. Schroeder, Zachary A. Sievert and Joshua T. Weinhandl
Hidenori Tanikawa, Hideo Matsumoto, Ikki Komiyama, Yoshimori Kiriyama, Yoshiaki Toyama and Takeo Nagura
It has been suggested that noncontact anterior cruciate ligament injury commonly occurs during sports requiring acute deceleration or landing motion and that female athletes are more likely to sustain the injury than male athletes. The purpose of this study was to make task-to-task and male-female comparisons of knee kinematics and kinetics in several athletic activities. Three-dimensional knee kinematics and kinetics were investigated in 20 recreational athletes (10 males, 10 females) while performing hopping, cutting, turning, and sidestep and running (sharp deceleration associated with a change of direction). Knee kinematics and kinetics were compared among the four athletic tasks and between sexes. Subjects exhibited significantly lower peak flexion angle and higher peak extension moment in hopping compared with other activities (P < .05). In the frontal plane, peak abduction angle and peak adduction moment in cutting, turning, and sidestep and running were significantly greater compared with hopping (P < .05). No differences in knee kinematics and kinetics were apparent between male and female subjects. Recreational athletes exhibited different knee kinematics and kinetics in the four athletic motions, particularly in the sagittal and frontal planes. Male and female subjects demonstrated similar knee motions during the four athletic activities.
Liam Anderson, Graeme L. Close, Matt Konopinski, David Rydings, Jordan Milsom, Catherine Hambly, John Roger Speakman, Barry Drust and James P. Morton
Maintaining muscle mass and function during rehabilitation from anterior cruciate ligament injury is complicated by the challenge of accurately prescribing daily energy intakes aligned to energy expenditure. Accordingly, we present a 38-week case study characterizing whole body and regional rates of muscle atrophy and hypertrophy (as inferred by assessments of fat-free mass from dual-energy X-ray absorptiometry) in a professional male soccer player from the English Premier League. In addition, in Week 6, we also quantified energy intake (via the remote food photographic method) and energy expenditure using the doubly labeled water method. Mean daily energy intake (CHO: 1.9–3.2, protein: 1.7–3.3, and fat: 1.4–2.7 g/kg) and energy expenditure were 2,765 ± 474 and 3,178 kcal/day, respectively. In accordance with an apparent energy deficit, total body mass decreased by 1.9 kg during Weeks 1–6 where fat-free mass loss in the injured and noninjured limb was 0.9 and 0.6 kg, respectively, yet, trunk fat-free mass increased by 0.7 kg. In Weeks 7–28, the athlete was advised to increase daily CHO intake (4–6 g/kg) to facilitate an increased daily energy intake. Throughout this period, total body mass increased by 3.6 kg (attributable to a 2.9 and 0.7 kg increase in fat free and fat mass, respectively). Our data suggest it may be advantageous to avoid excessive reductions in energy intake during the initial 6–8 weeks post anterior cruciate ligament surgery so as to limit muscle atrophy.
Sandra J. Shultz and Randy J. Schmitz
athletic population with and without anterior cruciate ligament injury . American Journal of Sports Medicine, 46 ( 7 ), 1606 – 1616 . PubMed ID: 29733680 doi:10.1177/0363546518768753 10.1177/0363546518768753 Ardern , C.L. , Taylor , N.F. , Feller , J.A. , & Webster , K.E. ( 2014 ). Fifty
Bradley S. Beardt, Myranda R. McCollum, Taylour J. Hinshaw, Jacob S. Layer, Margaret A. Wilson, Qin Zhu and Boyi Dai
ACL injury prevention programs. Developing a screening system for identifying high-risk populations will provide information for improving training programs while decreasing the numbers-needed-to-treat for injury prevention. Anterior cruciate ligament injuries commonly occur during jump-landing tasks
Xingda Qu, Jianxin Jiang and Xinyao Hu
, Clement DB . The potential role of prophylactic/functional knee bracing in preventing knee ligament injury . Sports Med . 2009 ; 39 ( 11 ): 937 – 960 . PubMed doi:10.2165/11317790-000000000-00000 19827861 10.2165/11317790-000000000-00000 2. Agel J , Evans TA , Dick R , Putukian M
D. Clark Dickin, Emily Johann, He Wang and Jennifer K. Popp
Drop height and fatigue have been shown in isolation to affect landing mechanics and increase the risk of sustaining an anterior cruciate ligament injury. The purpose of this study was to identify the combined effects of drop height and fatigue on landing mechanics in recreationally active females. To assess this, 11 healthy, young adult females performed a series of drop jumps from randomized heights before and following a lower extremity fatiguing protocol. Findings for kinematic results demonstrated that hip flexion decreased at initial contact (P = .003) and maximum hip (P = .005) and knee flexion (P = .001) angles increased with increases in drop height. Kinetic results demonstrated that vertical ground reaction forces and joint moments and powers increased as height increased. Ground reaction forces and maximum knee valgus increased from pre- to postfatigue with interactive effects observed in frontal plane hip angle at impact and peak ankle moment. These results confirm the effects of drop height and fatigue and highlighted interactions between these factors. The differential effect of fatigue as a function of drop heights helps to illustrate potentially risky situations that should be addressed in training and injury prevention programs.
Christine D. Pollard, Bryan C. Heiderscheit, Richard E.A. van Emmerik and Joseph Hamill
The purpose of this study was to determine if gender differences exist in the variability of various lower extremity (LE) segment and joint couplings during an unanticipated cutting maneuver. 3-D kinematics were collected on 24 college soccer players (12 M, 12 F) while each performed the cutting maneuver. The following intralimb couplings were studied: thigh rotation (rot)/leg rot; thigh abduction-adduction/leg abd-add; hip abd-add/knee rot; hip rot/knee abd-add; knee flexion-extension/knee rot; knee flx-ext/hip rot. A vector-coding technique applied to angle-angle plots was used to quantify the coordination of each coupling. The average between-trial standard deviation of the coordination pattern during the initial 40% of stance was used to indicate the coordination variability. One-tailed t-tests were used to determine differences between genders in coordination variability for each coupling. Women had decreased variability in four couplings: 32% less thigh rot/leg rot variability; 40% less thigh abd-add/leg abd-add variability; 46% less knee flx-ext/knee rot variability; and 44% less knee flx-ext/hip rot variability. These gender differences in LE coordination variability may be associated with the increased incidence of ACL injury in women. If women exhibit less flexible coordination patterns during competition, they may be less able to adapt to the environmental perturbations experienced during sports. These perturbations applied to a less flexible system may result in ligament injury.
Michaela Gstöttner, Andreas Neher, Arne Scholtz, Martin Millonig, Sandra Lembert and Christian Raschner
The aim of this study was to evaluate balance abilities and electromyographic (EMG) latency times of the preferred and nonpreferred leg in soccer players. Whereas side differences between the two legs in force, kicking speed, and joint laxity have been demonstrated in athletes in previous studies, no data are so far available on balance differences. Low balance ability is generally associated with an increased risk of ligament injuries, and the detection of a possible asymmetry in balance is important because a bilateral difference may be a contributing factor to injury. Twenty-one amateur soccer players were tested. Two different balance test instruments were used: the Biodex Stability System and the Tetrax System. For the evaluation of muscle latency times, EMGs were recorded by means of the EquiTest system. None of the tests performed in this study revealed statistically significant differences in balance ability between the preferred and the nonpreferred leg. The investigations of balance function and muscle response in amateur soccer players did not reveal significant differences between the preferred and nonpreferred leg in the current study. However, a certain tendency to better balance in the nonpreferred leg was observed.
Moataz Eltoukhy, Christopher Kuenze, Jeonghoon Oh, Eryn Apanovitch, Lauren Butler and Joseph F. Signorile
expensive and technically demanding motion capture systems. References 1. Agel J , Arendt EA , Bershadsky B . Anterior cruciate ligament injury in national collegiate athletic association basketball and soccer: a 13-year review . Am J Sports Med . 2005 ; 33 ( 4 ): 524 – 531 . PubMed ID: 15722283