concentric or eccentric contraction

[Laura01]

in discussion today.........
when going up stairs are hamstrings contracting concentrically or eccentrically? I mean the actual weight bearing part.
So far we have deduced that they are working eccentrically at the knee since the agonist and prime mover, the quads, are working concentrically. However they are also a hip extensors so therefore working concentrically?Can they work in both ways at different portions of the muscle?
opinions on this please!!
Laura

[roycar]

glute max would provide the majority of force needed for hip extension with the hamstrings being freed up to lengthen and pay out controlling and providing stability during knee extension..... in my opinion!

[Laura01]

yes, this is what i thought initially, but on having a go yourself, you can feel hamstrings being very active. confused!

[roycar]

maybe its neither?!

with hip flexion and knee flexion the pelvis would be in anterior tilt. going up the stairs, as the knee extends the hip extends too=posterior tilt of pelvis. the hams dont necessarily have to lengthen or shorten.... maybe hams stays the same and contract isometrically!