Normal Tracking During Flexion And Extension Of The Knee
Question
Describe the theoretical course of the patella during normal tracking during flexion and extension of the knee.
Given the normal knee ROM need for running, what phase of the patellar tracking is most likely involved?
Expert Answer
This solution was written by a subject matter expert. It’s designed to help students like you learn core concepts. Normal Tracking During Flexion And Extension Of The Knee
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The patella tracks normally as the knee joint flexes and stretches along a predetermined path. The patella rests in the lower portion of the trochlear groove of the femur as the knee extends. The patella slides up along the groove and toward the top of the femur as the knee flexes.
Explanation:
The patella is stabilized by a network of ligaments and muscles that help to keep it centered within the groove. The quadriceps muscles, which attach to the patella via the patellar tendon, play a significant role in this process. As the quadriceps contract, they pull on the patellar tendon, causing the patella to move up along the trochlear groove.
Step 2/3
The patella, or kneecap, is a small bone located in front of the knee joint. During normal tracking, the patella moves up and down within a groove on the femur (thigh bone) as the knee flexes and extends. This groove is known as the trochlear groove.
Explanation:
During knee extension (straightening), the patella sits in the lower part of the trochlear groove. As the knee flexes (bends), the patella slides up along the groove, moving towards the top of the femur. This movement is facilitated by the action of the quadriceps muscles, which pull on the patellar tendon, causing the patella to move.
During flexion, the patella also rotates laterally (outward) to some degree due to the oblique orientation of the trochlear groove. This lateral rotation helps to maintain proper alignment of the patella within the groove, and prevents it from dislocating.
Step 3/3
The normal knee range of motion (ROM) required for running involves repeated cycles of knee flexion and extension. The phase of patellar tracking that is most likely involved during running is the mid-range of knee flexion, typically around 30-60 degrees.
Explanation: Normal Tracking During Flexion And Extension Of The Knee
During this phase, the patella comes into contact with the femur and experiences the highest compressive forces. Proper patellar tracking and alignment during this phase are crucial to avoid overloading the joint and developing knee pain or injury.
Final answer
When running, the knee joint undergoes repeated flexion and extension cycles. The phase of patellar tracking most likely involved in running is the mid-range of knee flexion, typically around 30-60 degrees.
At this point, the patella is most likely to come into contact with the femur and to experience the highest compressive forces. Therefore, proper patellar tracking and alignment are essential to avoid overloading the joint and developing knee pain or injury. Normal Tracking During Flexion And Extension Of The Knee