Podcast
Questions and Answers
Which muscle is NOT involved in hip external rotation?
Which muscle is NOT involved in hip external rotation?
- Piriformis
- Obturator internus
- Quadratus femoris
- Gluteus maximus (correct)
What is the range of motion for hip external rotation when the knee is in flexion?
What is the range of motion for hip external rotation when the knee is in flexion?
- 75°
- 45° (correct)
- 60°
- 30°
Which of the following factors can limit the motion of hip external rotation?
Which of the following factors can limit the motion of hip external rotation?
- Flexibility of ankle ligaments
- Tension of hip medial rotator muscles (correct)
- Strength of hip adductor muscles
- Length of iliopsoas
What happens when there is weakness in hip external rotation?
What happens when there is weakness in hip external rotation?
What is the nerve supply for the quadratus femoris muscle?
What is the nerve supply for the quadratus femoris muscle?
Where does the piriformis muscle insert?
Where does the piriformis muscle insert?
Which muscle is responsible for laterally rotating the hip and stabilizing the joint?
Which muscle is responsible for laterally rotating the hip and stabilizing the joint?
What effect does contracture of hip external rotation have?
What effect does contracture of hip external rotation have?
Flashcards
Hip External Rotation Muscles
Hip External Rotation Muscles
The muscles responsible for rotating the hip outwards.
Piriformis Muscle Action
Piriformis Muscle Action
Externally rotates the hip and abducts the flexed thigh.
Quadratus Femoris Muscle
Quadratus Femoris Muscle
Laterally rotates and stabilizes the hip.
Obturator Internus Muscle
Obturator Internus Muscle
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Obturator Externus Muscle Action
Obturator Externus Muscle Action
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Hip External Rotation Range of Motion
Hip External Rotation Range of Motion
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Hip External Rotation Weakness Effect
Hip External Rotation Weakness Effect
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Hip External Rotation Contracture Effect
Hip External Rotation Contracture Effect
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Study Notes
Hip External Rotation
- Primary Muscles: Piriformis, Quadratus femoris, Obturator internus, Obturator externus, Gemellus superior, Gemellus inferior
- Range of Motion: 45 degrees of lateral rotation with the knee flexed. Less amplitude with a straight knee.
- Factors Limiting Motion: Tension of medial iliofemoral ligament and hip medial rotator muscles.
- Effect of Weakness: Weakness leads to medial rotation of the femur, pronation of the foot, and a knock-knee (valgus) position.
- Effect of Contracture: Contracture typically occurs in abduction and limits medial rotation in standing postures. Lateral rotation of the femur and outward-toeing are common.
Anatomy of Piriformis Muscle
- Origin: Anterior surface of sacrum, between sacral foramina.
- Insertion: Apex of greater trochanter.
- Nerve Supply: Sacral plexus.
- Action: External hip rotation and thigh abduction (especially in a flexed position).
Anatomy of Quadratus Femoris Muscle
- Origin: Lateral border of ischial tuberosity.
- Insertion: Quadrate tubercle of femur (just below lesser trochanter).
- Nerve Supply: Sacral plexus.
- Action: Lateral hip rotation and stabilization.
Anatomy of Obturator Internus Muscle
- Origin: Inner surface of obturator membrane and rim of pubis/ischial bordering membrane.
- Insertion: Middle part of medial aspect of greater trochanter of femur.
- Nerve Supply: Sacral plexus.
- Action: Lateral hip rotation and stabilization.
Anatomy of Obturator Externus Muscle
- Origin: Outer surface of obturator membrane, rim of pubis/ischium bordering it.
- Insertion: Trochanteric fossa on medial surface of greater trochanter.
- Nerve Supply: Obturator nerve.
- Action: Lateral hip rotation and stabilization.
Anatomy of Gemellus Superior Muscle
- Origin: Spine of ischium.
- Insertion: Middle part of medial aspect of greater trochanter of femur.
- Nerve Supply: Sacral plexus.
- Action: Lateral hip rotation and stabilization.
Anatomy of Gemellus Inferior Muscle
- Origin: Upper border of ischial tuberosity.
- Insertion: Middle part of medial aspect of greater trochanter of femur.
- Nerve Supply: Sacral plexus.
- Action: Lateral hip rotation and stabilization.
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