flexion relaxation (FR) phenomenon c509

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Questions and Answers

What is the flexion relaxation phenomenon?

It is a sudden cessation of muscular activity in the back extensors during trunk flexion. (correct)

It is an increase in muscular activity in the back extensors during trunk flexion.

It is a sudden increase in muscular activity in the back extensors during trunk flexion.

It is a gradual decrease in muscular activity in the back extensors during trunk flexion.

What is the Flexion Relaxation Phenomenon?

A sudden increase of muscular activity during trunk flexion

A sudden cessation of muscular activity during trunk flexion (correct)

A gradual increase of muscular activity during trunk flexion

A gradual decrease of muscular activity during trunk flexion

What is the difference in muscle activity between active erect and slouched sitting postures?

Muscle activity in the active erect sitting posture is greater than in both relaxed erect and slouched sitting. (correct)

Muscle activity in the slouched sitting posture is greater than in both relaxed erect and active erect sitting.

Muscle activity in the relaxed erect sitting posture is greater than in both active erect and slouched sitting.

Muscle activity is the same in all three sitting postures.

Which sitting posture requires less muscle activity due to flexion relaxation?

Slouched sitting posture Signup and view all the answers

What is the position of the LoG in relaxed erect sitting compared to active erect sitting?

The LoG is only slightly anterior to its position in active erect sitting. Signup and view all the answers

What happens to interdiscal pressure and disc degeneration with sustained slumped postures?

They increase Signup and view all the answers

What is the position of the LoG in the slouched posture?

The LoG is posterior to the spine and hips. Signup and view all the answers

Which posture requires a greater number of trunk muscles and increased level of activity in some muscles?

Active erect sitting posture Signup and view all the answers

What is the effect of sustained slumped postures on interdiscal pressure?

Sustained slumped postures increase interdiscal pressure Signup and view all the answers

Which muscles show greater activity in erect sitting than in slumped sitting?

Superficial lumbar multifidus, thoracic erector spinae, and internal oblique abdominal muscles Signup and view all the answers

What happens to the Load on Passive tissues in relaxed erect and slumped postures?

It remains the same Signup and view all the answers

Which muscles experience flexion relaxation in slumped and relaxed erect sitting, but not in active erect sitting?

The thoracic erector spinae muscles. Signup and view all the answers

What is the difference in LoG between active erect sitting posture and slumped posture?

LoG is more anterior in slumped posture than in active or relaxed erect sitting postures Signup and view all the answers

How does muscle activity in the lumbar erector spinae compare between slumped and relaxed erect sitting?

Muscle activity is the same in both sitting postures. Signup and view all the answers

What is the role of passive tissues in the relaxed erect and slouched postures?

Passive tissues are able to assume the load in both the relaxed erect and slouched postures. Signup and view all the answers

What was the method used by O'Sullivan and associates to monitor muscle activity in different sitting postures?

Electromyography (EMG Signup and view all the answers

Why do the thoracic erector spinae muscles cease their activity in slumped sitting?

Due to the passive tissues assuming the load Signup and view all the answers

Which posture requires a sudden increase of muscular activity during trunk flexion?

All sitting postures require a sudden increase of muscular activity during trunk flexion Signup and view all the answers

Which posture requires the least amount of muscle activity?