KNR 402 Pelvis and Thigh

What are the primary functions of the pelvic girdle?

To bear weight of the upper body when sitting and standing, transfer weight from axial to lower appendicular skeleton, serve as an attachment site for powerful muscles of locomotion and posture, and protect the lower urinary tract and internal reproductive organs.

What bones compose the pelvis?

Two innominate (coxal) bones and the sacrum.

What joints connect the right and left coxal bones?

Joined together at the symphysis pubis (anterior) and the sacroiliac joints (posterior).

What are the three main joints of the hip and pelvis?

Sacroiliac joints, the pubic symphysis, and the acetabulofemoral joint.

What type of joint are the sacroiliac joints?

Diarthroidal, synovial, planar joints with limited mobility.

What is the function of the symphysis pubis?

The symphysis pubis is an amphiarthroidal, cartilaginous joint that allows minimal movement and is supported by a fibrocartilaginous disc and ligaments.

What is the acetabulofemoral joint also known as?

Coxal joint

What type of joint is the acetabulofemoral joint?

Ball and socket joint, which is very stable and relatively immobile.

What are the movements allowed by the acetabulofemoral joint?

Allows flexion/extension, abduction/adduction, and internal/external rotation.

What ligaments contribute to the stability of the acetabulofemoral joint?

The ligaments include the labrum, joint capsule, iliofemoral ligament, pubofemoral ligament, ischiofemoral ligament, and ligamentum teres.

What is the origin and insertion of the iliofemoral ligament?

Originates from the AIIS and inserts on the intertrochanteric line.

What movements does the pubofemoral ligament prevent?

Prevents hyperabduction, external rotation, and extension.

What is the role of the ischiofemoral ligament?

Prevents excessive extension and internal rotation.

What is the function of the ligamentum teres?

Holds the head of the femur into the acetabulum and provides arterial blood supply to the head of the femur.

What are the three gluteal muscles?

Gluteus maximus, gluteus medius, and gluteus minimus.

What is the origin and action of the gluteus maximus?

The gluteus maximus originates from the sacrum, coccyx, and posterior iliac crest, and its action includes hip extension, external rotation, and abduction.

What is the primary action of the gluteus medius?

Hip abduction.

What additional actions do the anterior and posterior fibers of the gluteus medius perform?

The anterior fibers perform hip internal rotation and flexion, while the posterior fibers perform hip external rotation and extension.

What is the origin and action of the gluteus minimus?

Originates from the ilium between the anterior and inferior gluteal lines and acts in hip abduction, internal rotation, and assists in hip flexion.

What nerve innervates the gluteal muscles?

Innervated by the inferior gluteal nerve, while the gluteus medius and minimus are innervated by the superior gluteal nerve.

What are the six deep external rotators of the hip?

Piriformis, Superior Gemellus, Obturator Internus, Inferior Gemellus, Obturator Externus, Quadratus Femoris.

What is the common innervation for the deep external rotators of the hip?

All are innervated by the sacral plexus except for the obturator externus, which is innervated by the obturator nerve.

What are the primary hip flexors?

Iliopsoas Muscle (Iliacus, Psoas Major, Psoas Minor), Tensor Fascia Latae (TFL), Sartorius, Rectus Femoris.

What is the origin and insertion of the Iliacus muscle?

Origin: Iliac Fossa; Insertion: Lesser trochanter.

What actions does the Iliacus muscle perform?

Hip flexion, slight external rotation, trunk flexion (with femur fixed), anterior pelvic tilt.

What is the innervation of the Iliacus muscle?

Femoral nerve.

What is the origin and insertion of the Psoas Major muscle?

Origin: Bodies and transverse processes of lumbar vertebrae; Insertion: Lesser trochanter.

What actions does the Psoas Major muscle perform?

Hip flexion, slight external rotation, trunk flexion (with femur fixed), anterior pelvic tilt.

What is the innervation of the Psoas Major muscle?

Lumbar plexus.

What is the origin and insertion of the Psoas Minor muscle?

Origin: Bodies and transverse processes of lumbar vertebrae; Insertion: Superior ramus of pubis.

What action does the Psoas Minor muscle perform?

Posterior tilt of pelvis.

What is the innervation of the Psoas Minor muscle?

Lumbar plexus.

What are the origin and insertion points of the Tensor Fascia Latae?

Origin: Iliac crest, posterior to ASIS; Insertion: Iliotibial band.

What actions does the Tensor Fascia Latae perform?

Hip flexion, abduction, internal rotation.

What is the innervation of the Tensor Fascia Latae?

Superior Gluteal nerve.

What are the three compartments of the thigh musculature?

Anterior, Medial, Posterior.

What muscles are included in the Anterior Compartment of the thigh?

Quadriceps and Sartorius.

What is the innervation for the Anterior Compartment of the thigh?

Femoral nerve.

What is the origin and insertion of the Sartorius muscle?

Origin: Anterior Superior Iliac Spine; Insertion: Proximal Medial Surface of Tibia (Pes Anserine).

What actions does the Sartorius muscle perform?

Hip flexion, abduction, external rotation; knee flexion and internal rotation.

What are the four muscles that comprise the Quadriceps Femoris group?

Rectus Femoris, Vastus Intermedius, Vastus Lateralis, Vastus Medialis Oblique (VMO).

What is the unique characteristic of the Rectus Femoris muscle?

It is the only quadriceps muscle that crosses the hip joint.

What is the origin and insertion of the Rectus Femoris muscle?

Origin: Anterior Inferior Iliac Spine; Insertion: Patella via Quadriceps tendon and Tibial Tuberosity via Patellar tendon.

What actions does the Rectus Femoris muscle perform?

Knee extension and hip flexion.

What is the innervation of the Rectus Femoris muscle?

Femoral nerve.

What are the muscles that comprise the Hamstring group?

Biceps Femoris (Long Head and Short Head), Semitendinosus, Semimembranosus.

What is the innervation for the Hamstring muscles?

Primarily Tibial nerve, with Common fibular nerve innervating the short head of Biceps Femoris.

What is the origin and insertion of the Biceps Femoris Long Head?

Origin: Ischial Tuberosity; Insertion: Head of fibula.

What actions does the Biceps Femoris Long Head perform?

Hip extension, knee flexion, external rotation of flexed knee, tilting pelvis posteriorly.

What is the innervation of the Biceps Femoris Long Head?

Tibial nerve from the Sciatic nerve.

What is the origin and insertion of the Semimembranosus muscle?

Origin: Ischial Tuberosity; Insertion: Posterior surface of medial tibial condyle.

What actions does the Semimembranosus muscle perform?

Knee flexion, hip extension, internal rotation of flexed knee, tilting pelvis posteriorly.

What is the innervation of the Semimembranosus muscle?

Tibial nerve from the Sciatic nerve.

What is the origin of the Semitendinosus muscle?

Ischial Tuberosity

Where does the Semitendinosus muscle insert?

Medial Surface of the Proximal Tibia (Pes Anserine)

What actions are performed by the Semitendinosus muscle?

Knee Flexion, Hip Extension, Hip and Knee internal rotation, Tilt pelvis posteriorly

What is the innervation of the Semitendinosus muscle?

Tibial N. from the Sciatic N.

Which muscles are included in the Medial Compartment of the Thigh?

Pectineus, Adductor Brevis, Adductor Longus, Adductor Magnus, Gracilis

What is the innervation for the Adductor muscles in the medial compartment of the thigh?

Obturator N.

What is the origin of the Pectineus muscle?

Superior Pubic ramus

Where does the Pectineus muscle insert?

Superior linea aspera (pectineal line)

What are the actions of the Pectineus muscle?

Hip Adduction, Hip Flexion, and internal rotation

What is the innervation of the Pectineus muscle?

Femoral N. and Obturator N.

What is the origin of the Adductor Brevis muscle?

Inferior pubic ramus

Where does the Adductor Brevis muscle insert?

Proximal 1/3 Linea Aspera

What actions does the Adductor Brevis muscle perform?

Hip adduction, hip internal rotation, Hip flexion up to 70°, Hip extension past 80° of hip flexion.

What is the innervation of the Adductor Brevis muscle?

Obturator N.

What is the origin of the Adductor Longus muscle?

Superior pubic ramus, anterior side of symphysis

Where does the Adductor Longus muscle insert?

Middle 1/3 of Linea Aspera

What actions does the Adductor Longus muscle perform?

Hip adduction, Hip flexion up to 70°, Hip extension past 80° of hip flexion.

What is the innervation of the Adductor Longus muscle?

Obturator N.

What is the origin of the Adductor Magnus muscle?

Inferior pubic ramus, ischial ramus, ischial tuberosity

Where does the Adductor Magnus muscle insert?

Entire Linea Aspera, Adductor Tubercle

What actions does the Adductor Magnus muscle perform?

Hip Adduction, Hip internal rotation, Hip flexion, Posterior fibers: hip extension

What is the innervation of the Adductor Magnus muscle?

Obturator N. and Sciatic N.

What is the origin of the Gracilis muscle?

Inferior pubic ramus

Where does the Gracilis muscle insert?

Proximal Anteromedial Surface of Tibia (Pes Anserine)

What actions does the Gracilis muscle perform?

Hip Adduction and internal rotation, Knee Flexion

What is the innervation of the Gracilis muscle?

Obturator N.

What are the borders of the Femoral Triangle?

Inguinal Ligament, Sartorius, Adductor Longus.

What is the function of the pelvic floor muscles?

Provide stability, support organs, control sphincters, and are important for sexual function.