Wellness Articles

The Knee

The knee is one of the least secure joints in the human body. It is also the hardest joint to return to 100% following trauma so it is imperative you seek a diagnosis and treatment for an injury as soon as possible.

“Genu” is 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 centre of the knee, limits rotation and forward movement of the tibia in relation to the femur.
The posterior cruciate ligament (PCL), also in the centre 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, fibrous 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

Orthopaedic 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
4.Meniscus – “bounce” home, joint line tenderness, Apley’s compression and rotation, McMurray’s
5.Patellofemoral- Clarke’s, apprehension, patellar PA push
6.Patellar – passive glide, apprehension, compression
7.ITB – Noble, Ober
8.Other tests – Squat and rise, single leg stand, and duck walk

Have a great weekend!
Dr. Crysta Serné
Vancouver Chiropractor and owner of Vitality Clinic

• Posted: August 22, 2014
• |  by: Dr. Crysta Serne
• |   1 Comment
• |  Categories: Chiropractic, Sports Therapy, Wellness Articles
• |  Tags: ACL,  Anatomy,  Knee,  MCL,  Patella