Popliteus muscle: anatomy and functions

The muscle responsible for relaxing the knees while walking

Popliteal muscle

in the leg is used to unlock the knees when walking, with the sides rotating the femur on the tibia while keeping the chain part of the gait cycle closed (one leg in contact with the ground). In open chain movements (where the affected limb is not in contact with the ground), the popliteus muscle medially rotates the tibia on the femur. It is also used when sitting and standing. It is the only muscle in the back (back) of the lower leg that only affects the knee and not the ankle. The gastrocnemius muscle acts on both joints.

Structure [edit]

The popliteus muscle originates from the lateral surface of the lateral condyle of the femur with a rounded tendon. [1] Its fibers extend downward and inward. It attaches to the posterior surface of the tibia above the plantar line. [1] The muscle originates within the capsule of the knee joint, and its tendon separates the lateral meniscus from the collateral ligament of the joint.

Nervous nutrition [edit]

The popliteus muscle is supplied by the tibial nerve from the dorsal roots and.

Option [edit]

Sometimes there is an additional head from the sesamoid bone in the lateral (external) head of the gastrocnemius muscle.

Rarely an additional non-constant muscle; The popliteal secondary is visible. It originates from the femur on the inside of the plantaris muscle and enters the posterior ligament of the knee joint.

Peroneotibialis, 14% of the population. Origin - the inner side of the head of the fibula, confluence with the upper end of the oblique line of the tibia, lies below the popliteal bone. [2]

Another option, ciamella,

It is a small sesamoid bone embedded in the popliteus tendon. It is rare in humans, but is more commonly described in other primates and some other animals. [3]

Diagnostics

Due to its deep location, isolated PM injury is rare, but it can occur in association with other knee injuries such as anterior cruciate ligament or meniscal injuries.

There are common symptoms of muscle damage such as swelling, tenderness, swelling, and bleeding. If the PM is damaged, the patient may try to keep the leg (shin) in a position of external rotation while bending the knee.

To prevent damage to the PM, you need to check the following:

• Soreness. Since many neurovascular structures lie on top of the muscle, only its terminal portions can be palpated. The proximal part of the PM is palpable in the prone position. Pain at the posterior side of the knee may indicate damage to the biceps femoris tendon or lateral meniscus.
• Garrick test. In a sitting position, when the knee and hip joints are bent at an angle of 90 degrees, it is necessary to check the resistance of the lower leg to external rotation. The test is considered positive when pain occurs.
• Pain when removing shoes. The patient tries to remove the shoe from the healthy leg by pressing (medial rotation) into its heel with the toe of the affected leg. The test is considered positive when pain occurs.

As mentioned earlier, isolated damage to the PM is rare, and an isolated rupture of its tendon was found in 2 of 2412 cases (using MRI of the knee joint).

The popliteus, together with the posterior cruciate ligament, stabilizes the femur over the fixed tibia during stance, especially when additional stability is required, such as when running downhill.

Thus, running downhill and overpronating leads to PM injuries such as tenosynovitis, tendinopathy, sprain or tear.

Function [edit]

The popliteal joint helps flex the leg at the hip; when the leg is flexed, the tibia rotates inward.

It is especially active at the onset of knee flexion as it causes slight internal rotation of the tibia, which is important early in this movement.

When the knee is fully extended, the femur rotates slightly medially on the tibia to lock the knee joint in place. The popliteal joint is often referred to as the "key" to unlocking the knee because it initiates knee flexion by lateral rotation of the femur on the tibia. [4]

The popliteal joint also attaches to the lateral meniscus in the knee and pulls it posteriorly during knee flexion to prevent the meniscus from being crushed between the tibia and femur when the knee flexes.

Clinical relevance

Poor posture and irrational movement patterns can place excess stress on the midsection, which contributes to weakness and injury. Any knee injury will affect the PM.

If there is an imbalance of hamstrings, then the PM will weaken. Overpronation and collapse of the inside of the foot while walking or running will also put stress on the foot.

Various EMG studies have shown that the activity of the popliteus muscle increases during knee extension and downhill walking, so it plays an important role in the control of knee hyperextension.

Links[edit]

This article incorporates open access text from page 484 of the 20th edition

"Grey's Anatomy"
(1918).

1. ^ ab Strickland, Justin P.; Fester, Eric W.; Noyes, Frank R. (2017-01-01), Noyes, Frank R.; Barber-Westin, Sue D. (ed.), "2 - Lateral and Posterior Anatomy of the Knee", Noyes Knee Disorders: Surgery, Rehabilitation, Clinical Outcomes (Second Edition)
   , Elsevier, pp. 23–35, doi:10.1016/b978 -0-323-32903-3.00002-0, ISBN 978-0-323-32903-3, received 2021-03-01
2. Gray, Henry. 1918. Anatomy of the human body. Page Reshebnika 485
3. Akansel, Gur; Inan, Nagihan; Sarisoy, H. Tahsin; Anik, Yonka; Acancel, Sertac (2006). "The popliteus sesamoid muscle (Cyamella): Appearance on radiographs, CT and MRI." Surgical and radiological anatomy
   .
   28
   (6):642–645. DOI: 10.1007/s00276-006-0134-8. PMID 17066262. S2CID 13339926.
4. Wood, Addison; Boren, Morgan; Dodgen, Taylor; Wagner, Russell; Patterson, Rita M. (March 2021). "Muscular architecture of the popliteus muscle and key scientific findings". Knee
   .
   27
   (2): 308–314. DOI: 10.1016/j.knee.2019.12.001. ISSN 1873-5800. PMID 31954610.

Treatment

Treatment for acute PM injury is the same as for any other soft tissue, muscle, or tendon injury. Use the RICE or PRICE protocol (protection, rest, ice, compression, elevation) and nonsteroidal anti-inflammatory drugs.

Physical therapy in this case is of the same importance as in other pathologies associated with damage to soft tissue, muscles or tendons. This includes exercises for mobility, strength (e.g. eccentric training protocol), endurance, etc. It all depends on the patient’s condition and related problems.

Hamstring muscle[edit | edit code]

Home[edit | edit code]

Hamstring muscle

• Lateral femoral condyle, posterior horn of the lateral meniscus (posterior meniscofemoral ligament), arcuate ligament (part of the knee joint capsule)

Attachment[edit | edit code]

• Proximal third of the posterior fascia of the tibia, superficial to the origin of the soleus muscle from the line of the soleus muscle

Innervation[edit | edit code]

• Tibial nerve, L5-S1

Hamstring muscle

The lesion rarely presents as a single muscle syndrome; most often the muscle is affected simultaneously with the gastrocnemius and biceps muscles.

Clinic. When the muscle is affected, pain appears in the back of the knee joint when the joint is loaded (for example, when running, squatting, walking downhill and down stairs) and rarely occurs at rest (for example, at night).

Anatomy. A thin, flat, triangular-shaped muscle runs obliquely from the lateral surface of the lateral femoral condyle to the posterior medial aspect of the tibia proximal to the soleus line and forms the floor of the distal popliteal fossa behind the knee joint.

Function. Internal rotation of the tibia relative to the femur at the knee joint. Or in other words, the muscle prevents the lateral femoral condyle from rotating forward from the lateral superior articular surface of the tibia in the knee joint (together with the medial femoral extensors and sartorius muscles and against the resistance of the biceps femoris muscle). This internal rotation of the tibia is possible with a flexed hip and an unfixed tibia (for example, in a sitting position with a straight back).

External rotation of the thigh outwards in the knee joint with a fixed lower leg. Such a movement is possible, for example, when leaning on the leg, while the knee joint “opens”.

Slight flexion at the knee joint. Keeping the femur from moving forward and upward at the knee joint (on the upper articular surface of the tibia), when squatting with support on a bent knee (shared with the posterior cruciate ligament). {banner_st-d-1}

Diagnostics.

Popliteus muscle - Mayfield palpation - sitting position. The painful attachment of the muscle to the femur is palpated. Patient: sitting. Throws the affected leg over to the opposite leg, placing the outer surface of the lower leg on the thigh of the healthy leg, the foot hangs freely. Palpate the insertion of the muscle tendon on the lateral edge of the femoral condyle and then continue to palpate the tendon 2 cm proximal to the point where it passes posteriorly and inward from the fibular collateral ligament (a very clear landmark). Note: tenderness on palpation in the area where the muscle attaches to the femur can be detected with the patient lying on his back, or with the patient lying on his back with his legs positioned in the same way as in a sitting position.

Popliteus – Rotation tests – supine, prone or sitting position. The patient: sits or lies on his back or stomach, fixes the hip and bends the leg at the knee joint 90 degrees. Execution: passive external rotation and active internal rotation of the leg are performed against the doctor’s resistance. Evaluation of the research results: when the muscle is damaged, sharp pain and limitation of passive external rotation of the leg appear, and weakness appears when performing active internal rotation.

Popliteus - Extensor test - sitting or lying on your back. Execution: the patient tries to fully straighten the leg at the knee joint. Evaluation of the research results: when the muscle shortens, pain appears in the final phase of leg extension in the knee joint. Note: when the muscle is shortened, the range of extension is limited slightly. The test is not specific to the popliteus muscle.

Treatment. Pain in the back of the knee joint most often occurs when the gastrocnemius and biceps femoris muscles are affected. Such pain is associated with damage to the popliteus muscle only after examination and appropriate treatment of these muscles. Similar pain can occur with damage to the knee joint (inflammation, trauma, meniscus tear) and thrombophlebitis. {banner_st-d-2}

Popliteus muscle – Postisometric relaxation – prone position. Patient: lying on his stomach. The leg on the affected side is slightly bent at the knee joint (you can place a pillow in the ankle joint area), the thigh is rotated outward. 1. The doctor performs a preliminary passive stretch of the muscle by rotating the shin outward with a slight force until a light, springy, comfortable feeling of tissue tension (elastic barrier) appears and holds it for 3-5 s to adapt (accustom) the muscle to stretching. 2. The patient looks away from the restriction of movement (limitation of external rotation of the leg) or upward, inhales slowly and smoothly, holds his breath and tries to perform internal rotation of the leg with minimal effort against adequate light resistance from the doctor for 7-9 s. 3. The patient exhales slowly and smoothly, smoothly relaxes the muscles and turns his gaze towards the restriction of movement (towards the external rotation of the leg) or down, and the doctor performs additional soft, smooth passive stretching of the muscle by increasing the volume of external rotation of the leg with minimal effort until some springiness appears. tissue resistance (tension) or until mild pain appears for 5-10 s. In this new stretched position, the muscle is held in place by tension to repeat the isometric work. 4. The technique is repeated 4-6 times without breaking the stretching force between repetitions by carefully holding the muscle in a stretched state and without returning it to a neutral position.