Mechanics of the Hip & Knee Flashcards
In a general sense, why are lower extremities important?
Lower extremities are vital for locomotion and support of the rest of the body
In a general sense, are lower extremity injuries common? Why?
Lower extremity injuries and dysfunction are frequently common due to their involvement in the majority of our activities of daily living
What does the hip joint consist of, in Ramey’s words?
Consists of the articulation of the head of the femur with the acetabulum of the innominate
What is the ball and socket joint good for?
Stability
Different from the humerus, which has little osseous support. Hip has deep acetabular socket joint.
What are the major motions of the hip?
Major motions include flexion, extension, abduction, adduction, internal rotation and external rotation
What are some minor movements of the hip? What are restricted minor movements associated with?
Minor gliding motions do occur and are frequently restricted with somatic dysfunction
External rotation – head of femur glides anteriorly in acetabulum
Internal rotation – head of femur glides posteriorly in acetabulum
Explain what an externally rotated hip means.
Head of femur glides anteriorly in acetabulum
Explain what an internally rotated hip means.
Head of femur glides posteriorly in acetabulum
What are the ligaments of the hip?
Iliofemoral ligament
Ischiofemoral ligament
Ligamentum teres capitis femoris
What do hip ligaments do?
Help to guide and limit hip motion
What happens to make hip ligaments become stretched or lax?
Can become stretched/lax with improper use/imbalance/injury
Can also become tight and restricted with chronic injury or motion restriction/dysfunction
What can happen with a dislocated hip?
Dislocation of the hip damages the joint capsule, ligaments and blood supply and may result in the development of avascular necrosis of the head of the femur
How do the muscles of the hips generally work?
Muscles act as functional groups and fire together in patterns to produce motion
What are the flexor muscles of the hip?
psoas major iliacus pectineus rectus femoris sartorius
Where does the psoas major originate and insert?
Originates on the sides of T12-L5 vertebrae, associated intervertebral disks and the transverse processes of L1-L5
Inserts into lesser trochanter of femur
What innervates the psoas major muscle?
L1, 2, and 3
What symptoms are associated with dysfunction of the psoas major muscle?
Dysfunction of this muscle frequently seen with low back pain and hip problems
Commonly tight with low back pain
Pain can be referred to the anterior hip or thigh
What motion does a tight psoas major muscle limit?
Hip extension
What are the extensor muscles of the hip?
gluteus maximus and hamstring muscles
What is the origin of the gluteus maximus muscle?
Origin is widespread and includes: posterior gluteal line of ilium iliac crest aponeurosis of erector spinae, sacrum and coccyx sacrotuberous ligament fascia covering gluteus medius
Where does the gluteus maximus insert?
Iliotibial tract of fascia latae
What innervates the gluteus maximus?
Innervated by L5, S1 and S2 (inferior gluteal nerve)
What weakens the gluteus maximus muscle?
May become weak and inhibited with prolonged sitting and sedentary lifestyle and may need to be strengthened with rehabilitative exercises
What limits hip flexion?
Gluteus maximus and hamstring tension
What are the abductors of the hip?
gluteus medius and minimus
tensor fascia lata
sartorius
What is dysfunction of the tensor fascia latae frequently seen with?
frequently seen with lateral hip and lateral knee pain
Where does the gluteus medias muscle insert?
greater trochanter
Where does the gluteus medias muscle originate?
upper outer ilium
What innervates the gluteus medius muscle?
L5 and S1
superior gluteal nerve
What are the adductors of the hip?
adductors longus, brevis and magnus
obturator externus
gracilis
Where does the adductor longus muscle originate?
Anterior aspect of the pubis
Where does the adductor longus muscle insert?
Middle third of the femur
What innervates the adductor longus?
Obturator nerve
L2, L3, L4
What does tightness of adductor longus cause? What is it seen with?
Tightness frequently results in an inferior pubic symphysis shear (dysfunction of symphysis pubis)
Frequently seen with persistent groin pulls, especially those that are slow to respond to conservative treatment
What are the internal rotators of the hip?
tensor fascia latae
gluteus minimus and medius
Where does the gluteus minimus originate?
outer surface of ilium and greater sciatic notch
Where does the gluteus minimus insert?
greater trochanter
What innervates the gluteus minimus?
L5 and S1
superior gluteal nerve
What are the external rotators of the hip?
obturators gemelli quadratus femoris gluteus maximus sartorius piriformis
Where does the piriformis muscle originate?
Originates on:
anterior surface of sacrum
gluteal surface of ilium
capsule of sacroiliac joint
sometimes sacroiliac and sacrotuberous ligaments