The Knee
The knee is one of the least secure joints in the human body. It is the hardest joint to return to 100% following trauma. “Genu”- latin for knee. It actually means “bend.” Genu Valgum: knock-kneed Genu Varum: bow legged
Range of Motion
Resting position- 25° flexion Close packed position- Full extension with lateral rotation of the tibia Capsular Pattern- F, E Flexion: 0- 135° Extension: 0-15° Medial rotation: 20-30° Lateral Rotation: 30-40°
Muscles
Muscles that flex the leg: hamstrings, sartorius, TFL, gracilis, gastrocnemius, and popliteus. Muscles that extend the leg: quads. The Vastus Lateralis extends with external rotation of the tibia, all others cause internal rotation of the tibia.)
Ligaments
Ligaments are strong, elastic bands of tissue that connect bone to bone. They provide strength and stability to the joint. Four ligaments connect the femur and tibia: The medial collateral ligament (MCL) provides stability to the inner (medial) aspect of the knee. The lateral collateral ligament (LCL) provides stability to the outer (lateral) aspect of the knee. The anterior cruciate ligament (ACL), in the center of the knee, limits rotation and forward movement of the tibia in relation to the femur. The posterior cruciate ligament (PCL), also in the center of the knee, limits posterior movement of the tibia in relation to the femur. Other ligaments are part of the knee capsule, which is a protective, fiber-like structure that wraps around the knee joint. Inside the capsule, the joint is lined with a thin, soft tissue, called synovium.
Tendons
Tendons are tough cords of tissue that connect muscle to bone. In the knee, the quadriceps tendon connects the quadriceps muscle to the patella and provides power to extend the leg. The patellar tendon connects the patella to the tibia. Technically, it is a ligament, but it is commonly called a tendon.
O’Donahue’s Triad
Mechanism of injury- foot planted while sustaining lateral blow to outside knee Structures involved: 1.medial meniscus 2.MCL 3.ACL
Orthopedic Tests
Ligament Instability 1.MCL - ADD stress at 0 and 30° McMurray’s Joint line tenderness 2.LCL - ABD stress at 0 and 30° Joint line tenderness 3.ACL and PCL- Lachman’s Steinman’s Ant/Post drawer Meniscus - “bounce” home Joint line tenderness Apley’s compression McMurray’s Patellofemoral- Clarke’s apprehension Patellar PA push Patellar - passive glide Apprehension Compression ITB - Noble Ober Other tests - Squat and rise Single leg stand Duck walk" style="width: 295px; height: 244px" align="right" border="0" hspace="5" vspace="5" />The knee is one of the least secure joints in the human body. It is the hardest joint to return to 100% following trauma. “Genu”- latin for knee. It actually means “bend.” Genu Valgum: knock-kneed Genu Varum: bow legged
Range of Motion
Resting position- 25° flexion Close packed position- Full extension with lateral rotation of the tibia Capsular Pattern- F, E Flexion: 0- 135° Extension: 0-15° Medial rotation: 20-30° Lateral Rotation: 30-40°
Muscles
Muscles that flex the leg: hamstrings, sartorius, TFL, gracilis, gastrocnemius, and popliteus. Muscles that extend the leg: quads. The Vastus Lateralis extends with external rotation of the tibia, all others cause internal rotation of the tibia.)
Ligaments
Ligaments are strong, elastic bands of tissue that connect bone to bone. They provide strength and stability to the joint. Four ligaments connect the femur and tibia: The medial collateral ligament (MCL) provides stability to the inner (medial) aspect of the knee. The lateral collateral ligament (LCL) provides stability to the outer (lateral) aspect of the knee. The anterior cruciate ligament (ACL), in the center of the knee, limits rotation and forward movement of the tibia in relation to the femur. The posterior cruciate ligament (PCL), also in the center of the knee, limits posterior movement of the tibia in relation to the femur. Other ligaments are part of the knee capsule, which is a protective, fiber-like structure that wraps around the knee joint. Inside the capsule, the joint is lined with a thin, soft tissue, called synovium.
Tendons
Tendons are tough cords of tissue that connect muscle to bone. In the knee, the quadriceps tendon connects the quadriceps muscle to the patella and provides power to extend the leg. The patellar tendon connects the patella to the tibia. Technically, it is a ligament, but it is commonly called a tendon.
O’Donahue’s Triad
Mechanism of injury- foot planted while sustaining lateral blow to outside knee Structures involved: 1.medial meniscus 2.MCL 3.ACL
Orthopedic Tests
Ligament Instability 1.MCL - ADD stress at 0 and 30° McMurray’s Joint line tenderness 2.LCL - ABD stress at 0 and 30° Joint line tenderness 3.ACL and PCL- Lachman’s Steinman’s Ant/Post drawer Meniscus - “bounce” home Joint line tenderness Apley’s compression McMurray’s Patellofemoral- Clarke’s apprehension Patellar PA push Patellar - passive glide Apprehension Compression ITB - Noble Ober Other tests - Squat and rise Single leg stand Duck walk
