Physiotherapy with self patellar mobilization in knee pain and stiffness

 

Ordinarily, people see knee movement in bending (flexion) and straight (extension) that looks like one joint motion. In fact, basic knee complex bone anatomy includes femur, tibia, and patellae. The term knee complex was named due to it combining more than one joint. The knee complex is two articular joints that consists of a tibiofemoral and a patellofemoral joint. 

Knee motion in daily living
(Ref: https://www.crossfit.com/)

The patellofemoral plays an important role in the tibiofemoral motion. The tibiofemoral provides knee flexion and extension mainly. To complete knee biomechanics, patella or kneecap has to glide during knee flexion and extension that is related to the lever. 

Knee injury including intra - articular and extra - articular structure which develop patellae hypomobility or limited kneecap motion can affect knee bending and straight limitation. 

Knee joint anatomy
(Ref: https://www.sportssurgerychicago.com/)

Patellofemoral joint pain (PFP) is one of the most common conditions presented to the sports physical therapist. Disorders of this articulation are found in a variety of active individuals including runners, tennis players, and military personnel. Females tend to report more patellofemoral pain due to numerous speculations for this reason.

I have always given patellar mobilization in patients with kneecap pain and knee bending and straight limitation that stretching could not achieve motion, to decrease pain and increase knee range of motion.

        Basic biomechanically, the kneecap glides upward in knee straight whereas the kneecap seem gliding downward in knee bending.

Kneecap gliding related tibiofemoral function
(Ref: https://doctorlib.info/) 

I have arranged the mobilization for chronic patellar tendinitis, post ACL reconstruction, post PCL reconstruction, knee OA, Total Knee Replacement, stable lateral patellar dislocation, and ITB syndrome. 

The basic kneecap mobilization

Exercise #1: self massage around kneecap.

Exercise #2: Upward gliding (from toe to head direction): for improving knee straight.

Exercise #3: Downward gliding (from head to toe direction): for improving knee bending.

Exercise #4: Lateral gliding (from big toe side to little toe direction): for stretching medial patellofemoral ligament that I hardly glide to this direction.

Exercise #5: Medial gliding (from little toe side to big toe direction): for stretching lateral patellofemoral ligament and insertion of ITB. Because patellar lateral glide is more opportunity than medial glide from muscle imbalance or external force. I often glide to this direction in patients with lateral patellar dislocation and ITB syndrome. 

The tibiofemoral joint

            This joint is a connection of the tibia and femur that is the biggest of the knee complex. This joint not only provides flexion and extension motion but also allows transmission of body weight from the femur to the tibia while providing hinge-like, sagittal plane joint rotation along with a small degree of tibial axial rotation. To image a hinge joint is like a swing type door or window. 

Tibiofemoral joint anatomy consists of femur (thigh bone) and tibia (shin bone)
(Ref: https://www.lecturio.com/)

Functionally, the quadriceps muscle group and patellofemoral articulation—along with the tibialis anterior and ankle joint—act to dissipate forward momentum as the body enters the stance phase of the gait cycle. Hamstring group works behind this joint for bending the knee i.e. stepping during walking or running, up - down stairs. Additionally, hamstring provides assisted tibia rotation and prevents tibia forward translation. Tibia forward translation prevention too far can damage an ACL that can say hamstring is ACL knight. ITB is one that involves the knee joint, it provides lateral knee stability and tibia rotation.  

Hinge joint like
(Ref: https://brainly.in/)

Tibiofemoral joint effusion can be caused by ACL injury, PCL injury, Meniscus injury, cartilage injury, post operative ACL, post operative PCL, post operative meniscus, and knee articular replacement. The effusion can limit joint motion especially slightly knee flexion. Slightly knee flexion is the result of arthrogenic muscle inhibition (AMI) and increased joint space compensation. 

Gliding related ACL and PCL injury
(Ref: https://www.kneeandshouldersurgery.com/)

Ice compression to control effusion in this joint is one important component to increase range of motion. Sometimes, it needs tibiofemoral joint or patellofemoral joint mobilization to help range of motion improvement. 

The patellofemoral joint

    The patellofemoral joint consists of femur and patella (kneecap). The patellofemoral articulation is commonly referred to as the extensor mechanism. Although true that the concentric action of this motor unit is extension of the knee, functionally, the quadriceps acts eccentrically during gait, running, or jumping. 

Patella in trochlea groove of femur (femoral sulcus)
(Ref: http://kneereplacements.co.uk/)

The patella is the largest sesamoid bone in the body. Described in more detail in the section that follows, the patella is invested in the retinacular layer of the extensor mechanism receiving direct insertion of the deeper layer of the patellar tendon distally and the vastus intermedius proximally. 

Concave on its superficial surface, the articular surface of the patella contains a vertical central ridge that separates a broader lateral facet from a medial facet and a smaller, more medial odd facet. The patella articulates with the femoral sulcus or anterior articular surface of the distal femur, which is a coalescence of the medial and lateral femoral condyles. Matching the patella, the lateral portion of the femoral sulcus is relatively broader and contains a higher lateral ridge than the medial portion. This topography ascribes some bony stability to the joint when the patella is engaged in the sulcus at an angle of approximately 45 degrees of knee flexion.

Patella bone (kneecap)
(Ref: https://www.theskeletalsystem.net/)

The patellar tendon extends from the inferior pole of the patella and inserts on the tibial tubercle. Proximal to the tubercle it is separated from the underlying tibia by the infrapatellar tendon bursa. The patellar tendon comprises a superficial layer, which is contiguous with the retinacular layer, and a deeper layer, which is again the deep layer of the extensor mechanism. In the substance of the patellar tendon, these layers are largely adherent, much as the subscapularis tendon is to the anterior capsule of the shoulder joint.

Involved tendon of kneecap: quadriceps tendon (above kneecap) and patellar tendon (below kneecap)
(Ref: https://orthoinfo.aaos.org/)

In my physiotherapy experience, I have found patellar tendon and quadriceps tendon thickening and stiffness following the tibiofemoral effusion and after chronic patellar tendon inflammation. Stiffness of both structures develop patellar hypermobility in between head and toe direction that cannot achieve full flexion or extension. 

Some of my patients who got lateral knee pain or medial kneecap border pain from patellar lateral glide. This gliding is able to give shear force to medial patellofemoral ligament which are small connecting ligament between kneecap and femur. Moreover, the patellofemoral cartilage can be degenerated by lateral glide that develop to be patellofemoral pain syndrome afterward. Pushing kneecap toward to little to side direction is a part of lateral knee pain rehabilitation. 

If necessary, I have always recommend my patients to do self kneecap mobilization as home base program.  cannot achieve full flexion or extension.

Reference:

http://courses.washington.edu/bioen520/notes/Knee_Anatomy_&_Biomechanics_%28Flandry%29.pdf 

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jor.24120

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095937/

 

Physiotherapy with special dual posterior knee stretching in knee swelling.

SLR stretching with ACL brace
(Ref: https://www.choc.org/orthopaedics/)

  In my physiotherapy experience, I have a special stretching pose for specific conditions. The posterior knee tightness from swelling is a specific condition which can be found in knee joint injury. It is common in ACL injury, PCL injury, meniscus injury, knee degenerative, and postoperative all of them.

“The remarkable feature is slightly knee flexion with normal SLR range”. 

So, I never achieve full knee extension by SLR stretching. Physiotherapists and doctors have used the low - load long duration techniques including “Knee lag stretch” and “Prone knee hanging stretch” to improve full knee extension. Many patients do like the knee lag stretch because they feel more comfortable than the prone knee hanging stretch. I prefer the prone knee hanging stretch because I feel more effective. Do not sleep during stretching, you will get strong suffering at knee fold and hamstring tendon because of too long stretching.

Left side of picture illustrates knee swelling
(Ref: https://www.bjchealth.com.au/)

I have never seen any studies that compared the effectiveness of both of them. I cannot identify which one is the best. Select the best stretch following the surgeon recommendation, condition, precaution, and contraindication

The prone hanging is a stretch pose which hangs the target lower leg away from the edge of support for a while. The lower leg is pulled downward by gravity that will move away from the upper leg which is stationary with support. The result of this mechanic makes the soft tissue at the knee fold expand. 

Knee swelling with slightly knee flexion
(Ref: https://www.bjchealth.com.au/)

Exercise #1: The prone knee hanging stretch: Prone on the table with a towel as cushion at the table edge. Put the distal thigh or knee cap on the towel and relax the hamstring muscle that means do not go against the gravity. Try to keep the pelvic on the table. You can apply some weight at the ankle to increase stretch. I have selected weights between 3 - 10 kilograms that depend on the patient's body size.

Hold 1 - 5 minutes with rest 30 - 60 seconds. Make 3 - 5 reps/set and repeat 3 - 5 sets during the day. 

This exercise should not be done if the surgery was performed with a hamstring graft.

Exercise #2: The knee lag stretch: Sit or supine with a roll towel supports the heel that has space under the knee fold. Put some weight on the knee cap and let the knee straight as much as possible, that means do not bend the knee against the weight. I have selected weights between 5 - 10 kilograms that depend on the patient's body size.

Hold 1 - 5 minutes with rest 30 - 60 seconds. Make 3 - 5 reps/set and repeat 3 - 5 sets during the day. 

3 options to do the knee lag stretch
(1) by bag (2) by free weight equipment (3) by sand weight
(Ref: https://www.pogophysio.com.au/blog/)

It has been stretched by standard hamstring stretching that cannot straight that area. I have given SLR to some athletes that was normal range but the knee fold still was not straight. This is the reason which doctor and physiotherapist gave the knee lag stretch and the prone knee hanging stretch to solve the problem. 

Normal range of motion of knee
(Ref: https://favpng.com/)

In many textbooks, knee range of motion is described as 0 degree of extension and 135 or 140 degrees of flexion. However, 96% of the population has some degree of hyperextension. They found normal knee extension to be a mean of 5 degrees of hyperextension in males and 6 degrees of hyperextension in females. In my physiotherapy experience, I have seen slightly knee flexion between 5 - 30 degrees. 

Knee hyperextension in standing
(Ref: https://www.knee-pain-explained.com/)

Knee hyperextension in supine
(Ref: https://championptandperformance.com/)

Knee articular injury or injury into the knee joint, including knee surgery take many chain conditions. The most common is pain and joint effusion because there is some intra - articular fluid or blood. Pain can be caused by structure damage and intra - articular pressure from effusion. The intra - articular pressure can be a trigger of the pain impulse to the brain. 

Slightly knee flexion needs to be done to release pain from effusion. The strategy of releasing pain is to decrease pressure by increasing joint space so that the fluid will be distributed to that space. The trigger of the pain impulse gets less pressure that the pain intensity will decrease afterward. 

Moreover, knee joint effusion arises from joint injury, ACL tear, PCL tear, knee osteoarthritis (OA), and after knee surgery. One effect of knee joint effusion on quadriceps muscle is quadriceps arthrogenic muscle inhibition (AMI). On the other hand, I have never seen AMI in patients with MCL injury, LCL injury, or patellar tendinitis which are extra - articular structure. 

Ice compression to control swelling 20 minutes often.
(Ref: https://www.active.com/running/articles/)

Arthrogenic muscle inhibition (AMI) impedes the recovery of muscle function following joint injury, and in a broader sense, acts as a limiting factor in rehabilitation if left untreated. 

This common clinical scenario reflects an underlying neurophysiological phenomenon known as arthrogenic muscle inhibition (AMI) in which otherwise healthy muscle becomes reflexively inhibited following an injury to the joint. The AMI contributes to the characteristic muscle weakness, activation failure, and atrophy observed in patients recovering from joint injuries. The restoration of muscle function is not only essential to short-term recovery but also poses a threat to long term joint health and patient well-being if left unresolved. Therefore, AMI impedes the recovery of muscle function following joint injury, and in a broader sense, acts as a limiting factor in rehabilitation if left untreated.

 

Knee cap mobilization
(Ref: https://thenakedphysio.com/)

AMI has been linked to articular swelling, inflammation, pain, joint laxity, and structural damage. The relative importance of these factors is not clearly understood but it is generally accepted that AMI is caused by a change in the discharge of sensory receptors from the damaged knee joint. To understand this phenomenon from a neurophysiological perspective, we must consider motor neuron behavior as muscle function is dependent on both the availability of motor neurons and the ability to voluntarily recruit them.

  As early as 1965, we learned that capsular stretching in response to an experimental knee effusion causes a reflexive inhibition of the quadriceps. The resulting change in sensory information arising from joint mechanoreceptors was presumed to play an important role in this process. This observation was later repeated and confirmed in the early 1980s as we understood that the magnitude of inhibition was related to the amount of effusion present. Although pain was identified as an independent cause of AMI at that time, subsequent investigations confirmed it was not required to inhibit the surrounding musculature.

Neuromuscular Electrical Stimulation to restore VMO muscle function
(Ref: https://mikereinold.com/)

By theory, the treatment approach is simple by attempting to resolve (1) minimize pain, effusion, and inflammation of the injured joint; (2) improve muscle activation; and (3) minimize atrophy of the involved musculature.

My own protocol includes ice to control inflammation and swelling at the same time with the knee lag stretch or the prone knee hanging stretch, mobilize knee cap, facilitate quadriceps that focus on VMO by neuromuscular electrical stimulation, and activate quadriceps that focus on VMO by neuromuscular facilitation. Then, I have maintained all of them until effusion and muscle function are improved. 

In conclusion, the factor of slightly knee bending consists of knee joint posture adaptation for more comfortable position and decrease pain, and quadriceps dysfunction with AMI. They affect knee fold shortening including hamstring tendon. The low - load long duration techniques are needed to be a part of treatment. 

In ACL reconstruction, has could been started the low - load long duration techniques since the first day after operation for achieve knee ROM 0 - 90 degree in the first two week. The protocol recommends static 1 - 5 minutes with rest 30 - 60 seconds. Make 3 - 5 reps/set and repeat 3 - 5 sets during the day. 

In PCL reconstruction, has could been started the low - load long duration techniques since the first day after operation for achieve full knee extension in the first three months, and not allow to be hyperextension by three months. The protocol recommends holding 15 minutes for 4 reputation or 60 minutes of stretch time total per day. 

I cannot find a paper about recommendations for knee replacement patients. I have always selected the details following ACL reconstruction.   

Sand weight at ankle in the prone knee hanging
(Ref: https://www.researchgate.net/figure/Prone-Hang-Begin-without-weight-for-10-minutes-and-progress-to-increased-weight_fig1_22168841)

Reference:

https://www.jospt.org/doi/pdf/10.2519/jospt.2012.3871

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953293/ 

https://medicine.osu.edu/-/media/files/medicine/departments/sports-medicine/medical-professionals/knee-ankle-and-foot/pclfinal-document2020.pdf?la=en&hash=49FDFF419616E58163A1B5EE17A8CC39FA6B82BB

https://www.uwhealth.org/files/uwhealth/docs/sportsmed/SM-35549_ACL_Protocol.pdf 

https://www.researchgate.net/publication/356897678_Arthrogenic_Muscle_Inhibition_Best_Evidence_Mechanisms_and_Theory_for_Treating_the_Unseen_in_Clinical_Rehabilitation 

https://www.semanticscholar.org/paper/Quadriceps-arthrogenic-muscle-inhibition%3A-neural-Rice-McNair/619d6847dc03ead3a4cb2a4ab809b04ae48ebe29