3. How Does Rotation Differ From Circumduction?
1. Define nonaxial, uniaxial, biaxial and multiaxial joint movements. Give one example of each.
Nonaxial: slipping movement only; intercarpal joints
Uniaxial: movement in one plane; elbow
Biaxial: movement in two planes; jaw
Multiaxial: movement in or around all three planes; shoulder
2. How does rotation differ from circumduction?
Rotation is the turning of a bone around its own axis; circumduction is the circular movement of a limb. Circumduction can only be executed by a ball-and-socket joint, while the majority of rotation comes from pivot joints.
3. What is the specific role of the menisci of the knee? What about the anterior and posterior cruciate ligaments?
The meniscus is a piece of cartilage in the knee joint,
it helps to protect other more tender cartilage and to help with stability and weight distribution.
4. Why are sprains and cartilage injuries a particular problem?
Sprains happen when the ligaments reinforcing a joint are torn, while cartilage injuries (as the name suggests) involve the cartilage being torn or “popped”. Partially torn ligaments of a sprain are very slow to heal, and completely torn ones require surgery. Cartilage injuries always require surgical repair. These are a particular problem because in a lot of cases surgery is the only means of fixing these injuries.
5. List the functions of the following elements of a synovial joint: fibrous part of the capsule-permits movement of the joint, and resists dislocation. synovial fluid- lubricate and reduce friction, supply nutrients, and remove metabolic waste. articular cartilage-reduces friction, and absorbs shock.
Nonaxial: slipping movement only; intercarpal joints
Uniaxial: movement in one plane; elbow
Biaxial: movement in two planes; jaw
Multiaxial: movement in or around all three planes; shoulder
2. How does rotation differ from circumduction?
Rotation is the turning of a bone around its own axis; circumduction is the circular movement of a limb. Circumduction can only be executed by a ball-and-socket joint, while the majority of rotation comes from pivot joints.
3. What is the specific role of the menisci of the knee? What about the anterior and posterior cruciate ligaments?
The meniscus is a piece of cartilage in the knee joint,
it helps to protect other more tender cartilage and to help with stability and weight distribution.
4. Why are sprains and cartilage injuries a particular problem?
Sprains happen when the ligaments reinforcing a joint are torn, while cartilage injuries (as the name suggests) involve the cartilage being torn or “popped”. Partially torn ligaments of a sprain are very slow to heal, and completely torn ones require surgery. Cartilage injuries always require surgical repair. These are a particular problem because in a lot of cases surgery is the only means of fixing these injuries.
5. List the functions of the following elements of a synovial joint: fibrous part of the capsule-permits movement of the joint, and resists dislocation. synovial fluid- lubricate and reduce friction, supply nutrients, and remove metabolic waste. articular cartilage-reduces friction, and absorbs shock.