Lower Limb Anatomy Study Notes

Bones of the Lower Limb

Objectives

• Locate and identify each bone of the pelvic girdle and the lower limb.
• Locate and identify the surface features on the bones of the pelvic girdle and of the lower limb. Explore the functional importance of these features.
• Using directional terminology, describe the orientation of each bone of the pelvic girdle and lower limb within the human body.
• Determine whether the following bones are from the right side or the left side of the human body: os coxae (hip bone), femur, and tibia.

Bones of the Pelvic Girdle & Lower Limb

• Pelvic girdle:
  • Ossa coxae
  • Sacrum
• Lower limb bones:
  • Femur
  • Patella
  • Tibia
  • Fibula
  • Tarsals (7)
  • Metatarsals (5)
  • Phalanges (14)

Surface Features of the Pelvic Girdle

• Key landmarks include:
  • Ischial spine
  • Pubic tubercle
  • Ala of sacrum
  • Body of S1
  • Sacroiliac joint
  • Ischiopubic ramus
  • Pubic symphysis
  • Anterior superior iliac spine
  • Coccyx
  • Obturator foramen
  • Ischial tuberosity

Pelvic Girdle Orientation

Coronal Plane

• Landmarks:
  • Anterior superior iliac spine
  • Pelvic inlet
  • Pubic symphysis
  • Pubic tubercles

Midsagittal Plane

• True vs. False Pelvis:
  • True Pelvis:
  • Includes the sacrum, coccyx, and pelvic inlet
  • False Pelvis:
  • Enclosed by the abdominal wall and separates the true pelvis from the abdomen.
  • **Planes: **
  • Plane of pelvic brim
  • Plane of pelvic outlet
  • Pelvic axis
  • Posterior and Anterior sections marked

Sacrum Anatomy

Anterior View

• Components include:
  • Anterior sacral foramina
  • Median sacral crest
  • Sacral canal

Posterior View

• Components include:
  • Auricular surface
  • Superior articular process
  • Posterior sacral foramina

Os Coxae (Hip Bone) Anatomy

Lateral View

• Key parts include:
  • Ilium:
  • Iliac crest
  • Anterior superior iliac spine
  • Anterior inferior iliac spine
  • Greater sciatic notch
  • Ischium:
  • Ischial body
  • Ischial spine
  • Ischial tuberosity
  • Ischial ramus
  • Pubis:
  • Acetabulum
  • Body of pubis
  • Inferior ramus of pubis

Medial View

• Key parts include:
  • Ilium features as above
  • Arcuate line
  • Iliac fossa
  • Articular surface of pubis at pubic symphysis

Femur Anatomy

• Major features on the femur:
  • Greater trochanter
  • Neck
  • Fovea capitis
  • Femoral head
  • Intertrochanteric line
  • Intertrochanteric crest
  • Gluteal tuberosity
  • Linea aspera
  • Lesser trochanter
  • Anterior and posterior views indicating specific structures such as patellar surface, condyles, and epicondyles.

Patella Anatomy

Anterior View

• Components:
  • Base
  • Apex
  • Articular facet for medial femoral condyle

Posterior View

• Features include:
  • Vastus lateralis and medialis
  • Quadriceps tendon
  • Medial and lateral retinaculum

Tibia and Fibula Anatomy

Key Features of Tibia:

• Structures noted include:
  • Articular surfaces of medial and lateral condyles
  • Tibial tuberosity
  • Soleal line
  • Medial malleolus
  • Head of fibula
  • Anterior crest

Fibula:

• Structures include:
  • Head of fibula
  • Lateral malleolus

Bones of the Foot

Tarsal Bones (7):

• Talus
• Calcaneus
• Navicular
• Cuboid
• Cuneiforms (Medial, Intermediate, Lateral)

Phalanges (14):

• Divided into:
  • Proximal
  • Middle
  • Distal

Joints of the Lower Limb

Joint Overview:

• Pelvic girdle and lower limb joints:
  • Sacroiliac joint
  • Pubic symphysis
  • Hip joint (coxal)
  • Tibiofemoral joint (knee)
  • Proximal tibiofibular joint
  • Distal tibiofibular joint
  • Ankle joint
  • Intertarsal joints
  • Tarsometatarsal joints
  • Metatarsophalangeal joints
  • Interphalangeal joints

Knee Joint Overview

• Type: Synovial, modified hinge joint
  • Allows for: gliding and rotation
• Stability is enhanced by:
  • Surrounding muscles & ligaments (e.g. Quadriceps femoris muscle)
  • Patellar retinacula

Supporting Ligaments:

1. Patellar ligament:
   • Connects the patella to the tibial tuberosity
2. Medial (tibial) collateral ligament:
   • Connects medial epicondyle of the femur to the medial condyle of the tibia
   • Adhered to medial meniscus
3. Lateral (fibular) collateral ligament:
   • Connects lateral epicondyle of the femur to the head of the fibula
   • Separated from the lateral meniscus
4. Anterior cruciate ligament (ACL):
   • Attaches lateral condyle of femur to anterior intercondylar area of the tibia
   • Prevents anterior translation of tibia
5. Posterior cruciate ligament (PCL):
   • Attaches medial condyle of femur to posterior intercondylar area of the tibia
   • Prevents posterior translation of tibia

Menisci in the Knee

• Two semi-circular fibrocartilage structures act as shock-absorbers:
  • Medial Meniscus: Adhered to medial collateral ligament.
  • Lateral Meniscus: Separated from lateral collateral ligament by tendon of popliteus muscle.

Unhappy Triad Injury

• Components involve injury to:
  • Anterior Cruciate Ligament
  • Medial Collateral Ligament
  • Medial Meniscus

Knee Injuries Overview

• Common types of injuries:
  • ACL & PCL Tears:
  • ACL ruptures typically from hyperextension
  • PCL ruptures often occur from landing on tibial tuberosity with a flexed knee.

Study Tips with AI

• Use AI tools like Microsoft Copilot to enhance studying.
  • Create prompts to quiz yourself on bones, joints, and anatomical features.
  • Example prompt: "Test yourself on the bones of the pelvic girdle."
• Be specific, clear, and concise with your prompts when using AI
• Review responses and check against your lecture notes for accuracy.

Visualization Exercises

• Identify bones of the foot and their relationships (Calcaneus, Cuneiforms, Navicular, Metatarsals, Talus, Cuboid, and Phalanges).

Case Study Application

• For practical applications, consider case studies involving knee injuries and associate them with the anatomical structures involved.