Final answer:
The capsular pattern of restriction of the knee involves more limited passive flexion than extension due to ligament tightness or swelling. Key structures include the anterior and posterior cruciate ligaments, which support during knee extension and flexion respectively, and the extrinsic ligaments that stabilize against hyperextension and rotation.
Step-by-step explanation:
The capsular pattern of restriction of the knee joint refers to the typical pattern of limitation seen in joint movement due to capsular tightness or swelling. Within the knee, the intracapsular ligaments such as the anterior cruciate ligament and posterior cruciate ligament play vital roles. The anterior cruciate ligament is particularly crucial when the knee is extended, as it resists hyperextension. Conversely, the posterior cruciate ligament is stronger and provides support when the knee is flexed and weight bearing, preventing the femur from sliding anteriorly off the top of the tibia.
The extrinsic ligaments, including the tibial and fibular collateral ligaments, also contribute to knee stability by resisting hyperextension and rotation of the extended knee. The medial and lateral menisci, which sit between the femoral and tibial condyles, act as articular discs to provide cushioning and improve bone fit within the joint. When considering the capsular pattern of the knee, a common finding is more loss of passive flexion than passive extension.