Type

Journal Article

Authors

Giuseppe De Vito
Madeleine M Lowery
Massimiliano Ditroilo
Eamonn Delahunt
Rui Wu

Subjects

Physiotherapy & Sport

Topics
intensity cross talk subcutaneous tissue knee joint isometric contraction older women adipose tissue joint angles

Effect of Knee Joint Angle and Contraction Intensity on Hamstrings Coactivation. (2017)

Abstract This study investigated the effect of knee joint angle and contraction intensity on the coactivation of the hamstring muscles (when acting as antagonists to the quadriceps) in young and older individuals of both sexes. A total of 25 young (24 ± 2.6 yr) and 26 older (70 ± 2.5 yr) healthy men and women participated. Maximal voluntary isometric contraction of the knee extensors and flexors was assessed at two knee joint angles (90° and 60°, 0° = full extension). At each angle, participants performed submaximal contractions of the knee extensors (20%, 50%, and 80% maximal voluntary isometric contraction), whereas surface EMG was simultaneously acquired from the vastus lateralis and biceps femoris muscles to assess the level (EMG root-mean-square) of agonist activation and antagonist coactivation. Subcutaneous adipose tissue in the areas corresponding to surface EMG electrode placements was measured via ultrasonography. The contractions performed at 90° knee flexion demonstrated higher levels of antagonist coactivation (all P < 0.01) and agonist activation (all P < 0.01) as a function of contraction intensity compared with the 60° knee flexion. Furthermore, after controlling for subcutaneous adipose tissue, older participants exhibited a higher level of antagonist coactivation at 60° knee flexion compared with young participants (P < 0.05). The results of the present study suggest that 1) the antagonist coactivation is dependent on knee joint angle and contraction intensity and 2) subcutaneous adipose tissue may affect the measured coactivation level likely because of a cross-talk effect. Antagonist coactivation may play a protective role in stabilizing the knee joint and maintaining constant motor output.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

Giuseppe De Vito, Madeleine M Lowery, Massimiliano Ditroilo, Eamonn Delahunt, Rui Wu

Experts in our system

1
Giuseppe De Vito
University College Dublin
Total Publications: 42
 
2
Madeleine M. Lowery
University College Dublin
Total Publications: 49
 
3
Massimiliano Ditroilo
University College Dublin
Total Publications: 24
 
4
Eamonn Delahunt
University College Dublin
Total Publications: 115