lower extremity sports med notes

• Iliac Bone and Pubic Bone

  • Iliac: Refers to the iliac region of the pelvis.

  • Pubic Bone: The bone forming the front part of the pelvis.

  • Pubic Symphysis: Joint where the left and right pubic bones meet.

• Ischium

  • Commonly referred to as the "butt bone."

  • Ischial Tuberosity: Connects to the hamstring muscles.

  • Avulsion Fracture: Condition where the hamstring muscle pulls off from the ischial tuberosity, often associated with activities like sprinting or jumping.

• Hip Flexors

  • Iliopsoas: The main muscle group for hip flexion, which consists of the iliacus and psoas major/minor muscles.

  • Sartorius: A hip flexor that is not part of the quadriceps group but assists in hip flexion.

  • Quadriceps Group: Comprises four muscles:

    • Vastus Lateralis

    • Vastus Medialis

    • Vastus Intermedius (beneath the rectus femoris)

    • Rectus Femoris: Unique as it crosses the hip joint and assists with hip flexion.

    • the muscles that move the lower extremity are the strongest in the body

    • condromalacia injury

• Hip Extensors

  • Gluteus Maximus: The primary muscle for hip extension.

• Adductor Muscles

  • Comprises Adductor Brevis (short), Longus (long), Magnus (thick), and Gracilis (the longest that's not labeled as an adductor).

• Acetabulum

  • The socket in the pelvis where the femoral head fits.

  • Common site for fracture: Femoral Neck, due to horizontal stress making it more susceptible to shear forces.

• Acetabulofemoral Joint

  • Joint formed between the acetabulum and the femoral head.

  • Analogous to the glenohumeral joint in the shoulder.

• Knee Joint

  • A hinge joint responsible for flexion and extension.

  • Knee Flexion: Primarily performed by the hamstrings.

    • Hamstring Muscles:

      • Biceps Femoris

      • Semitendinosus

      • Semimembranosus

  • Knee Extension: Primarily performed by the quadriceps group.

• Knee Stability

  • Majority of stability provided by muscles rather than ligaments due to the knee's necessity for a wide range of motion.

  • Four Important Knee Ligaments:

    • ACL (Anterior Cruciate Ligament): Prevents anterior translation of the tibia on the femur.

    • PCL (Posterior Cruciate Ligament): Prevents posterior translation of the tibia on the femur.

    • MCL (Medial Collateral Ligament): Prevents valgus forces that could dislocate the knee medially.

    • LCL (Lateral Collateral Ligament): Prevents varus forces that could dislocate the knee laterally.

    • cruciate bc they cross

• Meniscus

  • Composed of two types:

    • Medial Meniscus: C-shaped, thicker, poor blood supply, commonly requires surgery for tears.

    • Lateral Meniscus: O-shaped, thinner, better blood supply, has a greater chance of healing itself.

  • Meniscus Tears: Often occur during twisting motions under compression, associated with ACL injuries (collectively known as the "unhappy triad" of ACL, MCL, medial meniscus).

• Key Terms

  • Valgus and Varus Forces: Mechanisms of injury where valgus stress leads to MCL tears and varus stress leads to LCL tears.

    • stress from outside impacts inside

    • stress from inside impacts outside

• patellofemoral joint

  • patella/kneecap rides in the trochlear groove of the femur

  • patella = a sesamoid/plate-shaped bone enveloped w/i the quadriceps tendon on the front of the knee & part of extensor mechanism

  • primary role is to give greater mechanical advantage in knee extension

  • allows knee flexion & extension to occur w/ a lesser amount of quadriceps force

  • increases quadriceps force by 33-50%

  • back of patella, which articulates with femur, is called the retropatellar surface

  • patellar tendonitis

    • inflammation of the patellar tendon

    • caused by high-force & repetitive strain

    • symptoms: anterior knee pain & local tenderness

    • treatment: activity modification, stretching, ice, bracing, and taping

  • Osgood-Schlatter Disease = growing pains in knee (tibial tuberosity)

  • Sinding-Larsen-Johansson = similar to osgood=schlatters but located differently

• q-angle

  • females = wider hips so larger q-angle = natural valgus force to outside of knee

  • males = narrower hips

  • glute med pulls hip into abduction so can counteract q-angle additional force

things to be able to identify:

• 4 major ligaments

  • acl

  • mcl

  • lcl

  • pcl

• medial & lateral condyles of the femur

• medial & lateral meniscus

• tibial tuberosity

• pre-patellar bursa

• pes anserine (& the 3 muscles that insert on it)

• popliteus muscle

• flexors & extensors of the knee (quads, sartorius, hamstrings)

• know the difference btwn the 3 hamstrings & 4 quad muscles

• adductor muscles

  • brevis

  • longus

  • magnus

  • gracilius