Effects of flexibility and strength interventions on optimal lengths of hamstring muscle-tendon units

Shangxiao Li, William E. Garrett, Thomas M. Best, Hanjun Li, Xianglin Wan, Hui Liu, Bing Yu

Research output: Contribution to journalArticle

Abstract

Objectives: The aim of the present study was to determine the effects of altering both hamstring flexibility and strength on hamstring optimal lengths. Design: Controlled laboratory study. Methods: A total of 20 male and 20 female college students (aged 18–24 years) participated in this study and were randomly assigned to either a flexibility intervention group or a strength intervention group. Passive straight leg raise and isokinetic strength test were performed before and after interventions. Paired T-tests were performed to determine hamstring flexibility or strength intervention effects on hamstring optimal lengths. Results: Male participants in the flexibility intervention group significantly increased range of hip joint flexion (P = 0.001) and optimal lengths of semimembranosus and biceps long head (P ≤ 0.026). Male participants in the strength intervention group significantly increased hamstring strength (P = 0.001), the range of hip joint flexion (P = 0.037), and optimal lengths of all three bi-articulated hamstring muscles (P ≤ 0.041). However, female participants did not significantly increase their hamstring optimal lengths in either intervention groups (P ≥ 0.097) although both groups significantly increased the range of hip joint flexion and strength (P ≤ 0.009). Conclusion: Hamstring optimal lengths can be modified through flexibility intervention as well as strength intervention for male participants, but not for female participants in this study. Hamstring optimal lengths should be considered as hamstring flexibility measures in future prospective studies to identify potentially modifiable risk factors for hamstring injury.

Original languageEnglish (US)
JournalJournal of Science and Medicine in Sport
DOIs
StateAccepted/In press - Jan 1 2019
Externally publishedYes

Fingerprint

Hip Joint
Leg
Prospective Studies
Students
Hamstring Tendons
Hamstring Muscles
Wounds and Injuries

Keywords

  • Hamstring muscle strain injury
  • Injury mechanism
  • Injury prevention
  • Modifiable risk factors
  • Muscle biomechanics

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Effects of flexibility and strength interventions on optimal lengths of hamstring muscle-tendon units. / Li, Shangxiao; Garrett, William E.; Best, Thomas M.; Li, Hanjun; Wan, Xianglin; Liu, Hui; Yu, Bing.

In: Journal of Science and Medicine in Sport, 01.01.2019.

Research output: Contribution to journalArticle

@article{70d4469ce2b04ed29246d68fbe01a805,
title = "Effects of flexibility and strength interventions on optimal lengths of hamstring muscle-tendon units",
abstract = "Objectives: The aim of the present study was to determine the effects of altering both hamstring flexibility and strength on hamstring optimal lengths. Design: Controlled laboratory study. Methods: A total of 20 male and 20 female college students (aged 18–24 years) participated in this study and were randomly assigned to either a flexibility intervention group or a strength intervention group. Passive straight leg raise and isokinetic strength test were performed before and after interventions. Paired T-tests were performed to determine hamstring flexibility or strength intervention effects on hamstring optimal lengths. Results: Male participants in the flexibility intervention group significantly increased range of hip joint flexion (P = 0.001) and optimal lengths of semimembranosus and biceps long head (P ≤ 0.026). Male participants in the strength intervention group significantly increased hamstring strength (P = 0.001), the range of hip joint flexion (P = 0.037), and optimal lengths of all three bi-articulated hamstring muscles (P ≤ 0.041). However, female participants did not significantly increase their hamstring optimal lengths in either intervention groups (P ≥ 0.097) although both groups significantly increased the range of hip joint flexion and strength (P ≤ 0.009). Conclusion: Hamstring optimal lengths can be modified through flexibility intervention as well as strength intervention for male participants, but not for female participants in this study. Hamstring optimal lengths should be considered as hamstring flexibility measures in future prospective studies to identify potentially modifiable risk factors for hamstring injury.",
keywords = "Hamstring muscle strain injury, Injury mechanism, Injury prevention, Modifiable risk factors, Muscle biomechanics",
author = "Shangxiao Li and Garrett, {William E.} and Best, {Thomas M.} and Hanjun Li and Xianglin Wan and Hui Liu and Bing Yu",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.jsams.2019.09.017",
language = "English (US)",
journal = "Journal of Science and Medicine in Sport",
issn = "1440-2440",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Effects of flexibility and strength interventions on optimal lengths of hamstring muscle-tendon units

AU - Li, Shangxiao

AU - Garrett, William E.

AU - Best, Thomas M.

AU - Li, Hanjun

AU - Wan, Xianglin

AU - Liu, Hui

AU - Yu, Bing

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Objectives: The aim of the present study was to determine the effects of altering both hamstring flexibility and strength on hamstring optimal lengths. Design: Controlled laboratory study. Methods: A total of 20 male and 20 female college students (aged 18–24 years) participated in this study and were randomly assigned to either a flexibility intervention group or a strength intervention group. Passive straight leg raise and isokinetic strength test were performed before and after interventions. Paired T-tests were performed to determine hamstring flexibility or strength intervention effects on hamstring optimal lengths. Results: Male participants in the flexibility intervention group significantly increased range of hip joint flexion (P = 0.001) and optimal lengths of semimembranosus and biceps long head (P ≤ 0.026). Male participants in the strength intervention group significantly increased hamstring strength (P = 0.001), the range of hip joint flexion (P = 0.037), and optimal lengths of all three bi-articulated hamstring muscles (P ≤ 0.041). However, female participants did not significantly increase their hamstring optimal lengths in either intervention groups (P ≥ 0.097) although both groups significantly increased the range of hip joint flexion and strength (P ≤ 0.009). Conclusion: Hamstring optimal lengths can be modified through flexibility intervention as well as strength intervention for male participants, but not for female participants in this study. Hamstring optimal lengths should be considered as hamstring flexibility measures in future prospective studies to identify potentially modifiable risk factors for hamstring injury.

AB - Objectives: The aim of the present study was to determine the effects of altering both hamstring flexibility and strength on hamstring optimal lengths. Design: Controlled laboratory study. Methods: A total of 20 male and 20 female college students (aged 18–24 years) participated in this study and were randomly assigned to either a flexibility intervention group or a strength intervention group. Passive straight leg raise and isokinetic strength test were performed before and after interventions. Paired T-tests were performed to determine hamstring flexibility or strength intervention effects on hamstring optimal lengths. Results: Male participants in the flexibility intervention group significantly increased range of hip joint flexion (P = 0.001) and optimal lengths of semimembranosus and biceps long head (P ≤ 0.026). Male participants in the strength intervention group significantly increased hamstring strength (P = 0.001), the range of hip joint flexion (P = 0.037), and optimal lengths of all three bi-articulated hamstring muscles (P ≤ 0.041). However, female participants did not significantly increase their hamstring optimal lengths in either intervention groups (P ≥ 0.097) although both groups significantly increased the range of hip joint flexion and strength (P ≤ 0.009). Conclusion: Hamstring optimal lengths can be modified through flexibility intervention as well as strength intervention for male participants, but not for female participants in this study. Hamstring optimal lengths should be considered as hamstring flexibility measures in future prospective studies to identify potentially modifiable risk factors for hamstring injury.

KW - Hamstring muscle strain injury

KW - Injury mechanism

KW - Injury prevention

KW - Modifiable risk factors

KW - Muscle biomechanics

UR - http://www.scopus.com/inward/record.url?scp=85073549548&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85073549548&partnerID=8YFLogxK

U2 - 10.1016/j.jsams.2019.09.017

DO - 10.1016/j.jsams.2019.09.017

M3 - Article

C2 - 31623958

AN - SCOPUS:85073549548

JO - Journal of Science and Medicine in Sport

JF - Journal of Science and Medicine in Sport

SN - 1440-2440

ER -