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
Fatigue has a tremendously adverse impact on pilot performance.This study aims to explore the Biceps Brachii(BB),Rectus Femoris(RF),Flexor Carpi Radialis(FCR),and Tibialis Anterior(TA)activities of fighter pilots in t...Fatigue has a tremendously adverse impact on pilot performance.This study aims to explore the Biceps Brachii(BB),Rectus Femoris(RF),Flexor Carpi Radialis(FCR),and Tibialis Anterior(TA)activities of fighter pilots in the early and late combat stages,and the target hitting time.A total of 13 volunteers were recruited to conduct simulated combats inside a real fighter cockpit.The surface Electromyography(sEMG)was collected from all volunteers in the initial and final 20s of flight,and the target hitting time during three simulated combats was recorded.The root mean square(RMS)values of right BB and TA were significantly higher than the left side values(p<0.001),while insignificant differences were found in the RMS values between the bilateral RF and FCR.Compared to the early flight period,the median frequency(MF)values of BB and TA were significantly lower during the late flight period,and the RMS values were significantly higher(p<0.047).Contrastively,the RMS values of FCR and RF differed insignificantly during the late flight period.Regarding the target hitting time,a significant difference was noted between task 1 and rask3.Subjects exhibit varying levels of muscle fatigue for different muscle groups before and after the flight.The muscle fatigue levels are asymmetrical on the left and right sides.Muscle fatigue might reduce the pilots'operational ability.This study provides a reference for fighter pilot fatigue protection and treatment.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.
基金the National Military Commission Logistics Department[Grant number:BZZ18J004].
文摘Fatigue has a tremendously adverse impact on pilot performance.This study aims to explore the Biceps Brachii(BB),Rectus Femoris(RF),Flexor Carpi Radialis(FCR),and Tibialis Anterior(TA)activities of fighter pilots in the early and late combat stages,and the target hitting time.A total of 13 volunteers were recruited to conduct simulated combats inside a real fighter cockpit.The surface Electromyography(sEMG)was collected from all volunteers in the initial and final 20s of flight,and the target hitting time during three simulated combats was recorded.The root mean square(RMS)values of right BB and TA were significantly higher than the left side values(p<0.001),while insignificant differences were found in the RMS values between the bilateral RF and FCR.Compared to the early flight period,the median frequency(MF)values of BB and TA were significantly lower during the late flight period,and the RMS values were significantly higher(p<0.047).Contrastively,the RMS values of FCR and RF differed insignificantly during the late flight period.Regarding the target hitting time,a significant difference was noted between task 1 and rask3.Subjects exhibit varying levels of muscle fatigue for different muscle groups before and after the flight.The muscle fatigue levels are asymmetrical on the left and right sides.Muscle fatigue might reduce the pilots'operational ability.This study provides a reference for fighter pilot fatigue protection and treatment.
