When performing conventional and Romanian deadlifts, the angle of the knee joint changes differently at the midpoint of the lift during both lifting and lowering phases, but not when the knee is at...
Mechanism
Synthesis from 1 study
How you hold your upper body changes how much your knees bend halfway through the lift — upright posture makes your knees bend more, while leaning forward lets them stay straighter. But when you’re all the way down, both ways need the same knee bend to reach the floor, so they match up there.
Most probable mechanism
When lifting with a more upright torso, the hips move less backward and the knees bend more to keep the bar close to the body, especially halfway up or down. When lifting with a more forward-leaning torso, the hips move farther back and the knees stay more straight, so they don’t bend as much at the same point in the movement. At the bottom, both movements require the same knee bend to reach the starting position, so the angles match there.
The torso angle during lift initiation determines the horizontal displacement of the center of mass relative to the hip and knee joints.
A more upright torso restricts posterior hip translation, forcing greater knee flexion to maintain bar path alignment over the mid-foot during mid-thigh phases.
A more horizontal torso allows greater posterior hip translation, reducing the need for knee flexion to maintain bar path alignment during mid-thigh phases.
At full knee flexion (knee height), both movement patterns require identical joint positions to achieve bar contact with the ground, resulting in converged knee angles.
Evidence from Studies
Supporting (1)
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Contradicting (0)
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