Effects of knee extension constraint training on knee flexion angle and peak impact ground-reaction force.


Journal Article

Low compliance with training programs is likely to be one of the major reasons for inconsistency of the data regarding the effectiveness of current anterior cruciate ligament (ACL) injury prevention programs. Training methods that reduce training time and cost could favorably influence the effectiveness of ACL injury prevention programs. A newly designed knee extension constraint training device may serve this purpose.(1) Knee extension constraint training for 4 weeks would significantly increase the knee flexion angle at the time of peak impact posterior ground-reaction force and decrease peak impact ground-reaction forces during landing of a stop-jump task and a side-cutting task, and (2) the training effects would be retained 4 weeks after completion of the training program.Controlled laboratory study.Twenty-four recreational athletes were randomly assigned to group A or B. Participants in group A played sports without wearing a knee extension constraint device for 4 weeks and then played sports while wearing the device for 4 weeks, while participants in group B underwent a reversed protocol. Both groups were tested at the beginning of week 1 and at the ends of weeks 4 and 8 without wearing the device. Knee joint angles were obtained from 3-dimensional videographic data, while ground-reaction forces were measured simultaneously using force plates. Analyses of variance were performed to determine the training effects and the retention of training effects.Participants in group A significantly increased knee flexion angles and decreased ground-reaction forces at the end of week 8 (P ≤ .012). Participants in group B significantly increased knee flexion angles and decreased ground-reaction forces at the ends of weeks 4 and 8 (P ≤ .007). However, participants in group B decreased knee flexion angles and increased ground-reaction forces at the end of week 8 in comparison with the end of week 4 (P ≤ .009).Knee extension constraint training for 4 weeks significantly altered lower extremity movement patterns and transferred these changes in lower extremity movement patterns to stop-jump and side-cutting tasks in which ACL injuries frequently occur. Training effects were retained 4 weeks after the training was completed but were diminished in magnitude.A knee extension constraint device may be a useful training tool in future ACL injury prevention programs to alter movement patterns without extra training time.

Full Text

Cited Authors

  • Liu, H; Wu, W; Yao, W; Spang, JT; Creighton, RA; Garrett, WE; Yu, B

Published Date

  • April 2014

Published In

Volume / Issue

  • 42 / 4

Start / End Page

  • 979 - 986

PubMed ID

  • 24532596

Pubmed Central ID

  • 24532596

Electronic International Standard Serial Number (EISSN)

  • 1552-3365

International Standard Serial Number (ISSN)

  • 0363-5465

Digital Object Identifier (DOI)

  • 10.1177/0363546513519323


  • eng