Functional Lower Limb Flashcards
How does the stress differ between the standing and seated arch of the pelvic joint complex?
Standing arch: superior rami of pubic bone stabilizes arch; seated arch: ischiopubic rami stabilize under stress.
What is the function of the pubic symphysis?
It holds hip bones together anteriorly, prevent “splaying” under stress.
What influences (controls) the sacroiliac joint?
The posterior sacro-iliac ligaments and the bony shape (interlocking) of the joint.
What is the function of the sacrotuberous, sacrospinous and iliolumbar ligaments?
Sacrospinous: prevents sacrum from moving postero-superiorly
Sacrotuberous: prevents pubic symphysis from moving anterosuperiorly
Iliolumbar ligaments: control lateral flexion of the vertebral column on the hip.
What is the acetabular labrum and what is its function?
The cartilaginous rim of the acetabulum that helps deepen the “fit” of the ball into the socket.
Name the capsular ligaments of the hip joint.
Anteriorly: ilifemoral (superior) and pubofemoral (inferior); posteriorly: ischiofemoral.
Which muscles act on the acetabulofemoral sling in extension/flexion?
Extension: gluteus maximus, flexion: psoas & ilacus.
Which muscles act on the acetabulofemoral sling in adduction/abduction?
Adduction: medial compartment mm. (adductor longus, magnus, brevis, the pectineus & gracilis); abduction: gluteus medius & minimus.
Which muscles act on the acetabulofemoral sling in internal rotation?
Internal rotation: tensor fascia lata.
Which muscles act on the acetabulofemoral sling in external rotation?
External rotation: piriformis, sup. gemellus, obturator internus, inf. gemellus & quadratus femoris + ext. obturator
Which form of rotation is similar to “lateral” rotation?
External rotation = lateral rotation.
What is the role of the rotators in gait?
The external rotators externally rotate the swinging limb to prevent its foot from striking on its lateral edge, internal rotators of grounded limb swing the contralateral side of the pelvis forward.
List the bursae of the hip.
Know ONLY the most important one, the iliopectineal due to infection of psoas spreading into the hip joint since it communicates with it.
What is a bursae?
A sac of synovial membrane with thin synovial fluid layer inbetween.
What is the function of a bursa?
The slippery walls allows free movement of skin over bony protuberances.
Which of the two collateral ligaments is attached to a meniscus?
The medial collateral ligament.
Why is this attachment clinically important?
Lateral trauma may damage medial collateral ligament which in turn disrupts the attached meniscus.
How do these collateral ligaments function as check ligaments of the knee?
They tighten as the joint EXTENDS preventing anterior movement of tibia on femoral condyles.
What movement(s) do the cruciate ligaments of the knee joint control/check?
The ACL controls forward movement of tibia on femur; the PCL controls posterior movement of these bones.
What muscles comprise the tibiofemoral sling?
The quadriceps (vasti lateralis, intermedius, medialis, rectus femoris) and the short head of biceps.
What actions do the muscles of the tibiofemoral sling produce?
The quadriceps - extend knee; the short head of biceps flexes the knee.
Name the two-joint muscles of the knee.
The rectus femoris coupled with the three vasti mm. quadriceps.
What is the action of these two-joint muscles on both joints?
Stabilizes the hip, mobilizes the knee.
What is the function of the hamstring muscles?
They flex the knee and extend the hip.