Anatomy Chapter 10: Pelvis Movements

Questions and Answers

What movement does the pelvis perform when it rotates about a vertical axis?

Lateral tilt

Anterior tilt

Right & Left rotation (correct)

Pelvic shift

What is the effect of a posterior pelvic tilt?

Increased lumbar lordosis and decreased hip extension

No change in lumbar lordosis and hip position

Decreased lumbar lordosis and increased hip extension (correct)

Increased lumbar lordosis and hip flexion

What happens to the pelvis during right and left lateral tilt?

The pelvis tilts forward or backward

The pelvis shifts laterally with no rotation

The pelvis remains stable without movement

The pelvis tilts laterally about the sagittal axis (correct)

What muscle shortening is associated with increased anterior pelvic tilt?

Shortened hip flexors Signup and view all the answers

Which of the following describes right and left pelvic shift?

The pelvis shifts laterally in a frontal plane Signup and view all the answers

What happens to the base of support when only the lower extremity is used?

It reduces to the area of the person's right foot. Signup and view all the answers

What effect does a lateral pelvic shift to the right have on the body's center of mass?

It moves the center of mass over the right foot. Signup and view all the answers

What occurs simultaneously when a lateral pelvic shift to the right is performed?

A lateral pelvic tilt to the left occurs. Signup and view all the answers

Which side of the pelvis is unsupported when performing a lateral pelvic shift to the right?

The left side. Signup and view all the answers

What identifies the direction of pelvic rotation?

The side of the pelvis that is farther forward Signup and view all the answers

What is the consequence of having only the right foot as the base of support?

Balance becomes unstable. Signup and view all the answers

During right pelvic rotation, which side of the pelvis is anterior to the other?

Right side is anterior to the left side Signup and view all the answers

What occurs when the left lower extremity is the weight-bearing extremity?

Right pelvic rotation Signup and view all the answers

What is lateral pelvic shift characterized by?

Side-to-side linear movement of the pelvis Signup and view all the answers

What movement works in conjunction with lateral pelvic shift?

Lateral pelvic tilt Signup and view all the answers

What characterizes lateral pelvic tilt?

One iliac crest is higher than the other Signup and view all the answers

Which hip movement occurs on the stance leg during lateral pelvic tilt?

Adduction Signup and view all the answers

What causes pelvic elevation?

Concentric contraction Signup and view all the answers

What is the term for the movement where one side of the pelvis is higher than the other?

Pelvic elevation Signup and view all the answers

Which muscle pair contributes to left pelvic elevation?

Left quadratus lumborum and right hip abductors Signup and view all the answers

Study Notes

Movements of the Pelvis

Right & Left Rotation: Rotates about a vertical axis.
Right & Left Lateral Tilt: Tilts laterally around the sagittal axis.
Right & Left Anterior/Posterior Tilt: Tilts about the frontal axis, affecting trunk and hip positions.
Right & Left Pelvic Shift: Lateral movement in the frontal plane without an axis of rotation.

Pelvic Tilts

Anterior Pelvic Tilt: As the anterior superior iliac spines (ASIS) move forward of the pubic symphysis, increased lumbar lordosis and hip flexion occur.
Posterior Pelvic Tilt: ASIS shift backward relative to the pubic symphysis, resulting in decreased lumbar lordosis and increased hip extension.

Muscles and their Effect on Pelvic Tilts

Shortened hip flexors: Lead to increased anterior pelvic tilt and enhanced lumbar lordosis.
Shortened hamstrings: Contribute to increased posterior pelvic tilt and reduced lumbar lordosis.

Lateral Pelvic Tilt

Exists when iliac crests are uneven; lateral movement causes one side to elevate and the other to lower.
Direction of tilt is determined by the lower side of the pelvis; commonly results from hip abductor weakness during single-leg stance.
Osteokinematic Movements:
- Adduction of the stance leg (higher side).
- Abduction of the unsupported leg (lower side).
Example: Standing on right leg without right hip abductors leads to left lateral pelvic tilt, where the left pelvis drops.

Pelvic Elevation

Defined as one side of the pelvis being higher, resulting from concentric contractions.
Often referred to as hip hiking.
Force Couple: Involves the left quadratus lumborum and right hip abductors.
Osteokinematic Movements:
- Adduction of the elevated hip (higher side).
- Abduction of the stance hip (lower side).

Pelvic Rotation

Occurs when one side of the pelvis moves forward or backward relative to the other.
Direction is identified by the forward side of the pelvis.
Right Pelvic Rotation: Right side moves anteriorly, often occurring with left hip medial rotation and left leg as the weight-bearer.
Left Pelvic Rotation: Left side anteriorly rotates with the left leg as the weight-bearer, producing left hip lateral rotation.

Lateral Pelvic Shift

A side-to-side linear movement accompanying lateral pelvic tilt, essential for balancing the center of mass over a single-leg base of support.
Example: In right single-leg stance, a lateral shift right aligns the center of mass over the right foot, with a concurrent left lateral pelvic tilt due to the left side being unsupported.

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Description

Explore the intricate movements of the pelvis, including rotations, tilts, and shifts. Understand how these movements contribute to overall body mechanics and posture. This quiz is essential for students of anatomy and physical education.