Anatomy Lab: Hip External Rotation

Overview

• Focus on hip external rotation mechanics, key muscles involved, and range of motion.
• Reminder to check the previous video on hip flexion for context.

Definition of Hip External Rotation

• Movement: Turning the thigh outward away from the body's midline.
• Importance: Crucial for activities such as walking, squatting, and balancing.

Prime Movers of Hip External Rotation

1. Gluteus Maximus

   • Origin: Ilium, sacrum, and coccyx.
   • Insertion: Iliotibial tract and gluteal tuberosity of the femur.
   • Function: Major contributor to external rotation, especially when hip is extended; generates force for sprinting and jumping; stabilizes hip joint.

2. Piriformis

   • Origin: Anterior surface of the sacrum.
   • Insertion: Greater trochanter of the femur.
   • Function: Important for external rotation, particularly when hip is extended; stabilizes hip joint.

3. Obturator Internus

   • Origin: Inner surface of the obturator membrane and surrounding bones.
   • Insertion: Greater trochanter of the femur.
   • Function: Assists in outward rotation and stabilizes the hip joint, especially when the hip is flexed.

Secondary Movers of Hip External Rotation

1. Sartorius

   • Origin: Anterior superior iliac spine (ASIS).
   • Insertion: Medial aspect of the tibia.
   • Function: Primarily aids in hip and knee flexion, but also assists in external rotation, especially when the hip is flexed.

2. Tensor Fasciae Latae (TFL)

   • Origin: Iliac crest.
   • Insertion: Iliotibial band.
   • Function: Stabilizes pelvis, controls thigh rotation, particularly important when the hip is neutral or slightly flexed.

Range of Motion

• Average External Rotation: Up to 60°.
• Influencing Factors: Individual flexibility, strength, and anatomical differences.

Additional Insights

• Example: Despite the thigh going inward, the femur head still undergoes external rotation.
• Training Considerations: Importance of both internal and external rotation in various sports and activities.
  • Examples:
    • Martial arts, dancing, gymnastics (control foot positioning)
    • Goalkeeping (switching between rotations to block shots)
    • Stretching post-workout (relaxing into external rotation feels beneficial).

Conclusion

• Next video will cover the range of motion of the hip to clarify misunderstandings.
• Reminder to follow on Instagram and check out posters for study aids.
• Appreciation for viewer comments and support.