Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibilit...Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown,which limited our understanding of risk factors for hamstring injury.This study was aimed at examining the relationships among hamstring muscle optimal length and flexibility and strength.Methods:Hamstring flexibility and isokinetic strength data and three-dimensional kinematic data for hamstring isokinetic tests were collected for11 male and 10 female recreational athletes.The maximal hamstring muscle forces,optimal lengths,and muscle lengths in standing were determined for each participant.Results:Hamstring muscle optimal lengths were significantly correlated to hamstring flexibility score and gender,but not to hamstring strength.The greater the flexibility score,the longer the hamstring muscle optimal length.With the same flexibility score,females tend to have shorter hamstring optimal muscle lengths compared to males.Hamstring flexibility score and hamstring strength were not correlated.Hamstring muscle optimal lengths were longer than but not significantly correlated to corresponding hamstring muscle lengths in standing.Conclusion:Hamstring flexibility may affect hamstring muscle maximum strain in movements.With similar hamstring flexibility,hamstring muscle maximal strain in a given movement may be different between genders.Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.展开更多
Background:Hamstring injury is one of the most common injuries in sports involving sprinting.Hamstring flexibility and strength are often considered to be modifiable risk factors in hamstring injury.Understanding the ...Background:Hamstring injury is one of the most common injuries in sports involving sprinting.Hamstring flexibility and strength are often considered to be modifiable risk factors in hamstring injury.Understanding the effects of hamstring flexibility or strength training on the biomechanics of the hamstring muscles during sprinting could assist in improving prevention strategies and rehabilitation related to these injuries.The purpose of this study was to determine the effects of altering hamstring flexibility or strength on peak hamstring musculotendinous strain during sprinting.Methods:A total of 20 male college students(aged 18-24 years)participated and were randomly assigned to either a flexibility intervention group or a strength intervention group.Each participant executed exercise training 3 times a week for 8 weeks.Flexibility,sprinting,and isokinetic strength testing were performed before and after the 2 interventions.Paired t tests were performed to determine hamstring flexibility or strength intervention effects on optimal hamstring musculotendinous lengths and peak hamstring musculotendinous strains during sprinting.Results:Participants in the flexibility intervention group significantly increased the optimal musculotendinous lengths of the semimembranosus and biceps long head(p<0.026)and decreased peak musculotendinous strains in all 3 bi-articulate hamstring muscles(p<0.004).Participants in the strength-intervention group significantly increased the optimal musculotendinous lengths of all 3 hamstring muscles(p<0.041)and significantly decreased their peak musculotendinous strain during sprinting(p<0.017).Conclusion:Increasing hamstring flexibility or strength through exercise training may assist in reducing the risk of hamstring injury during sprinting for recreational male athletes.展开更多
Background:The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting,until now,remained unknown,which limited our understanding of risk factors of hamstring muscle strain injury(hamstring i...Background:The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting,until now,remained unknown,which limited our understanding of risk factors of hamstring muscle strain injury(hamstring injury).As a continuation of our previous study,this study was aimed to examine the relationship between hamstring flexibility and peak hamstring muscle strains in sprinting.Methods:Ten male and 10 female college students participated in this study.Hamstring flexibility,isokinetic strength data,three-dimensional(3D)kinematic data in a hamstring isokinetic test,and kinematic data in a sprinting test were collected for each participant.The optimal hamstring muscle lengths and peak hamstring muscle strains in sprinting were determined for each participant.Results:The muscle strain of each of the 3 biarticulated hamstring muscles reached a peak during the late swing phase.Peak hamstring muscle strains were negatively correlated to hamstring flexibility(0.1179 ≤ R2≤ 0.4519,p = 0.001) but not to hip and knee joint positions at the time of peak hamstring muscle strains.Peak hamstring muscle strains were not different for different genders.Peak muscle strains of biceps long head(0.071 ± 0.059) and semitendinosus(0.070 ± 0.055) were significantly greater than that of semimembranosus(0.064 ± 0.054).Conclusion:A potential for hamstring injury exists during the late swing phase of sprinting.Peak hamstring muscle strains in sprinting are negatively correlated to hamstring flexibility across individuals.The magnitude of peak muscle strains is different among hamstring muscles in sprinting,which may explain the different injury rate among hamstring muscles.展开更多
基金supported by the National Natural Science Foundation of China(No.81572212)the Fundamental Research Funds for the Central Universities of China(No.2016BS013)
文摘Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown,which limited our understanding of risk factors for hamstring injury.This study was aimed at examining the relationships among hamstring muscle optimal length and flexibility and strength.Methods:Hamstring flexibility and isokinetic strength data and three-dimensional kinematic data for hamstring isokinetic tests were collected for11 male and 10 female recreational athletes.The maximal hamstring muscle forces,optimal lengths,and muscle lengths in standing were determined for each participant.Results:Hamstring muscle optimal lengths were significantly correlated to hamstring flexibility score and gender,but not to hamstring strength.The greater the flexibility score,the longer the hamstring muscle optimal length.With the same flexibility score,females tend to have shorter hamstring optimal muscle lengths compared to males.Hamstring flexibility score and hamstring strength were not correlated.Hamstring muscle optimal lengths were longer than but not significantly correlated to corresponding hamstring muscle lengths in standing.Conclusion:Hamstring flexibility may affect hamstring muscle maximum strain in movements.With similar hamstring flexibility,hamstring muscle maximal strain in a given movement may be different between genders.Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.
基金by a research grant from the National Natural Science Foundation of China(Grant No.81572212)the Fundamental Research Funds for the Central Universities of China(Grant No.2019PT015).
文摘Background:Hamstring injury is one of the most common injuries in sports involving sprinting.Hamstring flexibility and strength are often considered to be modifiable risk factors in hamstring injury.Understanding the effects of hamstring flexibility or strength training on the biomechanics of the hamstring muscles during sprinting could assist in improving prevention strategies and rehabilitation related to these injuries.The purpose of this study was to determine the effects of altering hamstring flexibility or strength on peak hamstring musculotendinous strain during sprinting.Methods:A total of 20 male college students(aged 18-24 years)participated and were randomly assigned to either a flexibility intervention group or a strength intervention group.Each participant executed exercise training 3 times a week for 8 weeks.Flexibility,sprinting,and isokinetic strength testing were performed before and after the 2 interventions.Paired t tests were performed to determine hamstring flexibility or strength intervention effects on optimal hamstring musculotendinous lengths and peak hamstring musculotendinous strains during sprinting.Results:Participants in the flexibility intervention group significantly increased the optimal musculotendinous lengths of the semimembranosus and biceps long head(p<0.026)and decreased peak musculotendinous strains in all 3 bi-articulate hamstring muscles(p<0.004).Participants in the strength-intervention group significantly increased the optimal musculotendinous lengths of all 3 hamstring muscles(p<0.041)and significantly decreased their peak musculotendinous strain during sprinting(p<0.017).Conclusion:Increasing hamstring flexibility or strength through exercise training may assist in reducing the risk of hamstring injury during sprinting for recreational male athletes.
基金supported by the National Natural Science Foundation of China(No.81572212)the Fundamental Research Funds for the Central Universities of China(No.2016BS013)
文摘Background:The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting,until now,remained unknown,which limited our understanding of risk factors of hamstring muscle strain injury(hamstring injury).As a continuation of our previous study,this study was aimed to examine the relationship between hamstring flexibility and peak hamstring muscle strains in sprinting.Methods:Ten male and 10 female college students participated in this study.Hamstring flexibility,isokinetic strength data,three-dimensional(3D)kinematic data in a hamstring isokinetic test,and kinematic data in a sprinting test were collected for each participant.The optimal hamstring muscle lengths and peak hamstring muscle strains in sprinting were determined for each participant.Results:The muscle strain of each of the 3 biarticulated hamstring muscles reached a peak during the late swing phase.Peak hamstring muscle strains were negatively correlated to hamstring flexibility(0.1179 ≤ R2≤ 0.4519,p = 0.001) but not to hip and knee joint positions at the time of peak hamstring muscle strains.Peak hamstring muscle strains were not different for different genders.Peak muscle strains of biceps long head(0.071 ± 0.059) and semitendinosus(0.070 ± 0.055) were significantly greater than that of semimembranosus(0.064 ± 0.054).Conclusion:A potential for hamstring injury exists during the late swing phase of sprinting.Peak hamstring muscle strains in sprinting are negatively correlated to hamstring flexibility across individuals.The magnitude of peak muscle strains is different among hamstring muscles in sprinting,which may explain the different injury rate among hamstring muscles.
