Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focu...Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focus on the prevention and rehabilitation of this injury.Hamstring injury commonly occurs in sporting events in which high speed sprinting and kicking are frequently performed,such as Australian football. English rugby,American football,and soccer.Basic science studies have demonstrated that a muscle strain injury occurs due to excessive strain in eccentric contraction instead of force,and that elongation speed and duration of activation before eccentric contraction affect the severity of the injury.Hamstring strain injury is likely to occur during the late swing phase and late stance phase of sprint running.Shortened optimum muscle length,lack of muscle flexibility,strength imbalance,insufficient warm-up,fatigue,lower back injury,poor lumbar posture,and increased muscle neural tension have been identified as modifiable risk factors while muscle compositions,age,race,and previous injuries are non-modifiable risk factors.The theoretical basis of some of these risk factors,however,is lacking,and the results of clinical studies on these risk factors are inconsistent.Future studies are needed to establish the cause-and-effect relationships between those proposed risk factors and the injury.展开更多
Background:Significant efforts have been made to identify modifiable risk factors of non-contact anterior cruciate ligament(ACL) injuries in male and female athletes.However,current literature on the risk factors for ...Background:Significant efforts have been made to identify modifiable risk factors of non-contact anterior cruciate ligament(ACL) injuries in male and female athletes.However,current literature on the risk factors for ACL injury are purely descriptive.An understanding of biomechanical relationship between risk and risk factors of the non-contact ACL injury is necessary to develop effective prevention programs. Purpose:To compare lower extremity kinematics and kinetics between trials with and without non-contact ACL injuries and to determine if any difference exists between male and female trials with non-contact ACL injuries regarding the lower extremity motion patterns. Methods:In this computer simulation study,a stochastic biomechanical model was used to estimate the ACL loading at the time of peak posterior ground reaction force(GRF) during landing of the stop-jump task.Monte Carlo simulations were performed to simulate the ACL injuries with repeated random samples of independent variables.The distributions of independent variables were determined from in vivo laboratory data of 40 male and 40 female recreational athletes. Results:In the simulated injured trials,both male and female athletes had significantly smaller knee flexion angles,greater normalized peak posterior and vertical GRF.greater knee valgus moment,greater patella tendon force,greater quadriceps force,greater knee extension moment. and greater proximal tibia anterior shear force in comparison to the simulated uninjured trials.No significant difference was found between genders in any of the selected biomechanical variables in the trials with simulated non-contact ACL injuries. Conclusion:Small knee flexion angle,large posterior GRF.and large knee valgus moment are risk factors of non-contact ACL injury determined by a stochastic biomechanical model with a cause-and-effect relationship.展开更多
文摘Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focus on the prevention and rehabilitation of this injury.Hamstring injury commonly occurs in sporting events in which high speed sprinting and kicking are frequently performed,such as Australian football. English rugby,American football,and soccer.Basic science studies have demonstrated that a muscle strain injury occurs due to excessive strain in eccentric contraction instead of force,and that elongation speed and duration of activation before eccentric contraction affect the severity of the injury.Hamstring strain injury is likely to occur during the late swing phase and late stance phase of sprint running.Shortened optimum muscle length,lack of muscle flexibility,strength imbalance,insufficient warm-up,fatigue,lower back injury,poor lumbar posture,and increased muscle neural tension have been identified as modifiable risk factors while muscle compositions,age,race,and previous injuries are non-modifiable risk factors.The theoretical basis of some of these risk factors,however,is lacking,and the results of clinical studies on these risk factors are inconsistent.Future studies are needed to establish the cause-and-effect relationships between those proposed risk factors and the injury.
文摘Background:Significant efforts have been made to identify modifiable risk factors of non-contact anterior cruciate ligament(ACL) injuries in male and female athletes.However,current literature on the risk factors for ACL injury are purely descriptive.An understanding of biomechanical relationship between risk and risk factors of the non-contact ACL injury is necessary to develop effective prevention programs. Purpose:To compare lower extremity kinematics and kinetics between trials with and without non-contact ACL injuries and to determine if any difference exists between male and female trials with non-contact ACL injuries regarding the lower extremity motion patterns. Methods:In this computer simulation study,a stochastic biomechanical model was used to estimate the ACL loading at the time of peak posterior ground reaction force(GRF) during landing of the stop-jump task.Monte Carlo simulations were performed to simulate the ACL injuries with repeated random samples of independent variables.The distributions of independent variables were determined from in vivo laboratory data of 40 male and 40 female recreational athletes. Results:In the simulated injured trials,both male and female athletes had significantly smaller knee flexion angles,greater normalized peak posterior and vertical GRF.greater knee valgus moment,greater patella tendon force,greater quadriceps force,greater knee extension moment. and greater proximal tibia anterior shear force in comparison to the simulated uninjured trials.No significant difference was found between genders in any of the selected biomechanical variables in the trials with simulated non-contact ACL injuries. Conclusion:Small knee flexion angle,large posterior GRF.and large knee valgus moment are risk factors of non-contact ACL injury determined by a stochastic biomechanical model with a cause-and-effect relationship.
