Popliteus Muscle

Description

Popliteus

The popliteus is a small, slender, triangular musclotendinous complex in the sole of the foot with the popliteus muscle and the popliteofibular ligament forming part of the outer edge of the knee.. It is the deep, shallow muscle of the knee joint with the popliteus fossa a it is in the body. It also makes up the lateral musculature of the knee joint along with the iliotibial band. It is the only muscle in the posterior compartment of the lower leg (which also includes tibialis posterior flexor digitorum longus and flexor hallucis longus) which is mono-articular and does not influence the ankle joint.

It is one of the main posterolateral stabilisers of the knee joint causing both medial and lateral rotation of the knee [1] thereby being involved in both the closed chain phase and open-chain phase of the gait cycle.[2] It also works as a smaller stabilizer in regard to internal rotation anterior translation and varus power.

Origin

The muscle fibres originate from the lateral condyle of the femur and the posterior horn of the lateral meniscus via a strong tendon called the popliteus tendon. Cadaveric dissections have also shown fibres originating from the styloid portion of the fibular head which then runs obliquely blending with the main muscular structure.[2]

From there, it moves down and medial to the Tibia. It passes over the top of the posterior thigh and part of the joint to lie there as the deepest part of the posterior knee. The popliteal tendon closes the joint but does not penetrate the synovium. The popliteus ntini no fa lateral collateral ligament (LCL) ne biceps femoris ntini no ase.

The popliteal bursa is usually an extension of the synovium that separates it from the lateral femoral condyle. Although the popliteus has an extra-articular region, it is a sac-like structure that separates the lateral meniscus of the knee from the lateral collateral ligament. additional The popliteal head probably arises from the sesamoid of the lateral head of the gastrocnemius muscle. An extra destabilizing muscle rarely seen, called the popliteus minor, originates from the femur medial to the plantaris and inserts into the posterior ligament of the knee United.

The popliteus muscles are intra-capsular but have extra-articular and extra-synovial muscles.

Insertion

It inserts on the tibia just proximal to the soleal line but below the tibial condyles.

Nerve

The popliteus muscle is supplied by the tibial nerve from spinal nerve roots L4 through S1 with approximately 2 to 3 parallel tibial nerve branches. The entry point of the nerve is the lateral distal margin of the muscle which is found inferior to the fibular head and then splits into anterior medial and lateral divisions throughout the nerve.

Artery

Popliteus muscle is provided by 2 arteries-

• medial inferior geniculate branch of popliteal artery
• vascular branches of the posterior tibial artery.

[3]

Function

The popliteus assists in knee flexion and its function depends on the position of the lower body, weight-bearing or non-weight-bearing, as it is the primary internal rotator of the tibia in the non-weight-bearing position. [2]

1. In open chain kinematics it rotates the tibia medially
2. In proximal chain internal kinematics, it rotates the femur externally during initial knee flexion.
3. And extension when weight-bearing ‘locking’ the knee occurs. In this position, the femur rotates medially over the tibia to allow full extension without muscle compromise. When the knee is ‘opened’ the popliteus muscle must contract to cause flexion and lateral rotation of the the femur on the tibia thereby providing the muscle with the word – ‘key’ to the locked knee.
4. During the knee flexion, the Popliteus muscle retracted back the half -moon plate backwards to avoid being stranded between the femoral and tibia. [2]
5. In the knee stability -due to the often found that Popliteus tendon is connected to the side sac, this makes the muscles work in the back and outer stability of the knee [4] [5]. Krudwig et al. [6] regarded Popliteus as an important structure that resisted over -rotating over outer tibia Even if all other rear outer ligaments are cut off, the neutral tibia rotates.

Clinical relevance

It usually participates in the rear and outer side (PCL) corner injury of the knee, which is secondary to-

1. varus force applied to a flexed knee.
2. Hit the knee directly (inside to outside).
3. varus/hyperextension ( from both contact and non-contact injuries) .
4. dislocation of the knee.

Regardless of the injury mechanism of the PCL angle (from the above), an emergency assessment of the emergency assessment of the state of neuropathy of the patient’s limbs was performed. In the case of knee dislocation, evaluate the state of blood vessels, then close the knee joint closed, and then reduce again Evaluate the state of blood vessels.

Further trauma differential motion mode and posture are usually stressed on Popliteus muscle, making it vulnerable to weakness and damage. It is very common for the medical damage of this muscle, which may lead to poor functionality, so it becomes vital -especially after the knee Reconstruction surgery. Smaller knees also need to pay more attention, because the risk of POP damage has increased. [2]

Popliteal tendinopathy can also occur as a side effect of knee pain. However, it can be difficult to exclude due to other common local knee pain. As this muscle prevents excessive tibial rotation along with preventing significant anterior translation of the knee it can be pathologically overcome secondary to excessive sprinting or running downhill and so such activities should be avoided or adapted to running on flat surfaces such as a treadmill.

If the side leg tendons are stronger than the inner (inside) rope muscle, then the popliteus muscle will be weak. Excessive rotation or collapse of the feet in the opposite direction when walking or running will be Popliteus [7].

Different EMG studies have shown that popliteus activity increases with knee extension and downhill walking, thus solidifying its role in controlling knee hyperextension [8].

The referred pain pattern for the popliteus trigger point is the back of the knee [9].

For more information on the pathology of the upper popliteal muscle on Physiopedia, read: Popliteal Strain Popliteus Tendonitis

Assessment

Due to its deep location, isolated injuries of the popliteus are rare but may be associated with other knee injuries such as ACL injuries or meniscus injuries.

Signs of nerve injury are present including swelling tenderness edema bleeding patient causing lateral rotation of the leg (tibia) during knee flexion.[10].

The following should be checked to rule out a popliteus injury.

1. Tenderness – Only the distal portion of the popliteus is palpable due to the many neurovascular structures that lie on it. Check for proximal tendon tenderness in prone position, while posterolateral knee tenderness may be a sign of biceps femoris tendon strain and/or lateral meniscus Injuried.
2. Garrick test [11] – Pt in a high sitting position with hips and knees bent at 90 degrees. Apply calf external rotation resistance. Pain during this movement is considered a positive test
3. Shoe removal maneuver [11] The patient attempts to remove the contralateral shoe by internally rotating the affected leg to reach the heel of the contralateral leg. Pain during this movement indicates an injury to the popliteus.

As mentioned previously, isolated injuries of the popliteus are rare, with only 2 of 2412 knee MRI studies [12] showing isolated acute rupture of the popliteus tendon.

The popliteus and PCL (posterior cruciate ligament) stabilize the femur on the immobilized tibia during the stance phase, especially when activities such as downhill running require additional stability. Therefore, excessive internal rotation downhill, especially on sloped surfaces, can cause the popliteus to Muscle injuries such as tenosynovitis tendinopathy ruptures and strains. [13]

[14]

Treatment

Treatment of popliteus lesions is the same as for any soft tissue injury and muscle injury or tendinopathy. Anti-inflammatory drugs such as RICE Therapy or PRICE Therapy (Protected Rest Elevation Compression Elevation.

Physical therapy is consistent with other soft tissue and muscle injuries and includes mobility exercises, strengthening exercises, eccentric training, and additional rehabilitation options, depending on the pathologically relevant injury and patient condition.

[15]

Exercise

1. Sit with your feet dorsiflexed so that your heels touch the ground. Perform internal rotation of the foot. Can be used with or without a resistance band and strapped to the ball of the forefoot.
2. Hamstring Relaxation – After sitting for long periods of time with the puck behind bent knees, look for areas of softness. Slowly increase the pressure. If the tenderness or numbness moves to a slightly different area, add movement with internal and external rotation of the calf.
3. Isometrically perform internal rotation with forefoot on sitting bar or table.
4. Open-chain full ROM of knee with a resistance band tied behind the forefoot against internal rotation.
5. Closed-chain proprioceptive exercises on a BOSU ball with the affected leg secured on a BOSU ball and crossed lunges performed.
6. One leg jumps forward with the knee slightly bent.