Hip And Knee Complex

The condition of genu valgus refers to a "knocked-knee" posture, where the knees are positioned inward, causing the lower legs to angle outward. This posture puts excessive stress on the medial structures of the knee, leading to overstretching. At the same time, it compresses the lateral structures of the knee. Therefore, the correct answer is that the "knocked-knee" posture causes an overstretch of the medial structures of the knee and compression of the lateral structures of the knee.

Genu varus refers to a condition where the legs appear bowed outwards, with the knees being farther apart than the ankles. The given answer states that the "bow-leg" posture causes overstretching of the lateral structures of the knee and compression of the medial structures of the knee. This explanation aligns with the definition of genu varus, as the lateral structures of the knee are stretched and the medial structures are compressed in this condition.

Using the cane on the opposite side helps to shift weight off of the painful/weaker hip and widens the base of support for stability. This is because when the cane is used on the opposite side, it allows the individual to lean on the cane and transfer some of their body weight onto it, reducing the load on the painful/weaker hip. Additionally, using the cane on the opposite side widens the base of support, providing more stability and balance while walking.

Genu recurvatum refers to the hyperextension of the knee joint, where the knee bends backwards beyond its normal range of motion. This condition occurs when there is an overstretching of the posterior structures of the knee, such as the hamstrings and the posterior capsule, and compression of the anterior structures of the knee, including the patella and the quadriceps tendon. This imbalance in forces leads to the abnormal alignment of the knee joint and the characteristic backward bending.

The primary movers of hip flexion are the rectus femoris, sartorius, and iliopsoas muscles. The adductor magnus and longus muscles are not involved in hip flexion, but rather in hip adduction. Therefore, they are not included in the list of primary movers for hip flexion.

The rectus femoris and hamstrings are the muscles of the hip joint that are affected by knee position. The rectus femoris is one of the quadriceps muscles and it crosses both the hip and knee joints. It is responsible for flexing the hip and extending the knee. The hamstrings, on the other hand, are a group of muscles located at the back of the thigh. They cross both the hip and knee joints and are responsible for extending the hip and flexing the knee. Therefore, the position of the knee can affect the function and tension of both the rectus femoris and hamstrings.

The medial meniscus and ACL (anterior cruciate ligament) are the structures of the knee that are most commonly prone to injury. The medial meniscus is a C-shaped cartilage that acts as a shock absorber between the thighbone and shinbone, while the ACL is one of the main ligaments that provide stability to the knee joint. These structures can be injured through activities such as sports, sudden twisting movements, or direct impact to the knee, leading to pain, swelling, and instability in the knee joint.

The muscles that flex the knee are the hamstrings, sartorius, and gastrocnemius. The peroneus longus muscle, however, is not involved in knee flexion. It is located in the lower leg and is responsible for eversion (turning the foot outward) and plantar flexion (pointing the foot downward). Therefore, the correct answer is Peroneus longus.

The patella functions as an anatomic pulley for the quadriceps muscles, meaning it helps to change the direction of the force generated by the quadriceps muscles. The patella also functions as a boney protection to the distal surfaces of the condyles during knee flexion, providing extra support and stability to the knee joint. Additionally, the patella functions to reduce friction between the quadriceps tendon and femoral epicondyles, allowing for smooth movement of the knee joint. However, the patella does not function to decrease leverage of the quadriceps tendon.

The patella functions as an anatomic pulley for the quadriceps muscle, allowing it to exert greater force on the tibia. It also functions as a bony protection to the distal surfaces of the condyles during knee flexion, preventing damage to the joint. Additionally, the patella helps to reduce friction between the quadriceps muscle and femoral epicondyles, allowing for smoother movement. However, it does not function to decrease leverage of the quadriceps muscle.

During one-leg stance, the gluteus medius muscle on the weight-bearing leg and the quadratus lumborum muscle on the non-weight bearing leg need to contract to help prevent pelvis drop on the opposite side of the weight-bearing leg. The gluteus medius is responsible for stabilizing the pelvis and preventing it from dropping, while the quadratus lumborum helps to maintain the alignment of the pelvis and spine. This combination of muscle contractions ensures proper balance and stability during one-leg stance.

When the knee is in the closed packed position, it is in its most stable position. In this position, the femur rotates externally on the tibia, causing the tibia to lock in place. This is known as the screw-home mechanism. When the knee is locked in this position, the quadriceps muscles do not need to contract to maintain knee extension. Instead, the mechanical structures of the screw-home mechanism provide stability and maintain knee extension. Therefore, muscle contraction of the quadriceps musculature is minimal or non-existent in the closed packed position.

The given answer is correct because it accurately explains the difference between coxa vara and coxa valga. Coxa vara refers to a larger angle of inclination, which means that the neck of the femur is tilted more vertically, resulting in an increase in leg length. On the other hand, coxa valga refers to a smaller angle of inclination, meaning that the neck of the femur is tilted less vertically, resulting in a decrease in leg length.

The primary functions of the hip complex include providing support and protection to the abdominal cavity, providing stability and helping to transmit forces between the upper body and the ground, and providing mobility for locomotion and placing the lower extremities in space. However, the hip complex does not operate mostly in an open kinematic chain and is not independent of the positions of the spine. In fact, the hip complex is closely connected to the spine and its position and movements are influenced by the spine.

When there is pain or weakness in the muscles of one hip, the body tends to compensate by adopting a posture that helps to alleviate the discomfort. In this case, during unilateral stance on the weaker/painful hip, the trunk laterally flexes toward the weaker/painful hip. This means that the trunk bends sideways towards the side of the affected hip. Additionally, there is a pelvic drop on the uninvolved side, which means that the opposite side of the pelvis drops down. This compensatory posture helps to distribute the load and reduce strain on the weaker/painful hip.

During unilateral stance on the weaker/painful hip, the compensatory posture that occurs at the trunk is trunk lateral flexion toward the weaker/painful hip with pelvic drop on the uninvolved side. This means that the person will lean their trunk towards the side of the weaker/painful hip while the opposite side of the pelvis drops. This posture helps to shift the weight away from the weaker/painful hip and provide stability during stance.

When the hip is fully flexed and the knee is fully extended, the hamstring muscles are in a shortened position at both joints. This causes the muscles to become passively insufficient, meaning they are unable to generate as much force as they would be able to in a more optimal length-tension relationship. This can limit the ability of the hamstrings to generate force and contribute to movements such as hip extension and knee flexion.

The closed packed position of the hip joint refers to the position in which the joint is most stable and has the least amount of mobility. In this position, the hip is extended, meaning the thigh bone is moving backward, and internally rotated, meaning the thigh bone is rotated inward. This position allows for maximum contact between the surfaces of the hip joint, providing stability and support.

A minimal range of motion (ROM) of 0-20 degrees for hip abduction, hip internal rotation, and hip external rotation is needed for most daily functions. This means that the hip joint needs to be able to move within this range in order to perform basic activities such as walking, sitting, and standing. Any ROM beyond this range is not necessary for most daily functions.

When moving from a standing position to a sitting position, the hip and knee joints undergo flexion. The rectus femoris muscle controls knee flexion with an eccentric contraction, meaning that it is lengthening while generating force. The hamstrings control hip flexion with an eccentric contraction as well. This means that the hamstrings are lengthening while generating force to control the movement of the hip joint.

When the hip is fully flexed and the knee is fully extended, the Rectus Femoris muscle becomes active insufficient. This means that the muscle is unable to generate its maximum force because it is shortened and in a position where it cannot contract effectively. This is because the Rectus Femoris crosses both the hip and knee joints and functions as a hip flexor and knee extensor. When both joints are in their end ranges of motion, the muscle is at a mechanical disadvantage and cannot generate optimal force.

The knee joint is primarily responsible for supporting body weight in a standing position, transferring body weight during locomotion, and lengthening and shortening the lower extremity. However, it does not directly provide mobility for actions of the hip and spine. The hip and spine have their own separate joints and muscles that allow for movement and mobility. Therefore, the statement that the knee joint functions to provide mobility for actions of the hip and spine is incorrect.

The dynamic stabilizers of the knee help to provide stability and control movement of the knee joint. The quadriceps femoris and extensor retinaculum, hamstring musculature, and pes anserinus are all examples of dynamic stabilizers. However, the soleus and anterior tibilais are not involved in stabilizing the knee joint. Therefore, the correct answer is Soleus & anterior tibilais.

The normal joint end feel for full knee flexion is a soft end feel. This means that there is a cushioned sensation when the knee reaches its maximum flexion, indicating the presence of soft tissue compression. This can be attributed to the compression of the articular cartilage and the soft tissues surrounding the knee joint, such as the muscles and ligaments.

The patella, also known as the kneecap, is not considered a static stabilizer of the knee. Static stabilizers are structures that help maintain the stability of the knee joint by providing support and preventing excessive movement. The iliotibial band, ACL, PCL, collateral ligaments, menisci, and joint capsule are all examples of static stabilizers. The patella, on the other hand, plays a role in the mechanical advantage of the quadriceps muscle and aids in knee extension.

The gluteus maximus is not a primary mover of hip abduction. The primary movers of hip abduction include the gluteus medius, gluteus minimus, and sartorius muscles. The gluteus maximus is primarily responsible for hip extension and external rotation.