Question

The Skeletal System to compare the ball-and-socket joints of the hip and shoulder. Describe the structures that contribute to stability, and types of injuries likely to impact each joint. Respond to at least one other student's. Cite supporting reference information in APA format.

Answer 1

The ball-and-socket joint is a sort of synovial or diarthrodial joint that we would find in the shoulder and hip as an instance of these joints. Generally speaking, synovial joints enable movement with a common core across an indefinite amount of axes. The motions are bending, extension, abduction, rotation, and circumduction. There are several structures in the framework of a synovial joint: two bones coated in articular cartilage and a tight space between them, called the articular cavity comprising the viscous synovial fluid needed for lubricating the joint.

Within the joint capsule, the fluid is retained which envelops the entire joint in a continuum with the periosteum of the bones engaged in that particular joint. Synovial joints require extra constructions for motion and stability. These include muscles, tendons, bursa and ligaments.

There are prevalent injuries to the shoulder joint. Repetitive use of the upper limb, especially in abduction such as throwing, swimming, or racqueting sports, may result in severe or chronic inflammation of the bursa or muscle tendons, glenoid labrum tears, or rotator cuff degeneration or tears. Because the humeral head is strongly supported by muscles and ligaments around its anterior, superior, and posterior aspects, most dislocations of the humerus occur in an inferior direction.

This can happen when force is applied to the humerus when the upper limb is completely removed, such as when you dive to catch a baseball and land on your side or elbow. Inflammatory reactions to any shoulder injury can lead to the formation of cicatric tissue between the articular capsule and adjacent structures, decreasing the mobility of the shoulder, a disease called adhesive capsulitis

The radial collateral ligament supports the elbow's lateral side. This stems from the humerus ' lateral epicondyle and then blends into the annular ligament's lateral part. The annular ligament surrounds the radius head. This ligament promotes the radius head as it articulates at the proximal radioulnar joint with the ulna's radial notch. This is a pivot joint that enables the radius to rotate during the forearm's supination and pronation.

The patellar ligament continues from the patella to the anterior tibia just below the knee. The quadriceps femoris acting through the patella and patellar ligament is a strong muscle acting to stretch the arm at the knee. It also serves as a “dynamic ligament” to provide very important support and stabilization for the knee joint..

There are prevalent knee injuries. Since this joint is supported mainly by muscles and ligaments, there will be pain or knee instability caused by injury to any of these structures. Injury to the posterior cruciate ligament happens when the knee is flexed and the tibia is pushed backwards, such as falling and landing on the tibial tuberosity or hitting the tibia on the dashboard without wearing a seatbelt during a car accident. More commonly, when forces are applied to the extended knee, injuries occur, especially when the foot is planted and can not move.