Saturday, January 16, 2010

The Popliteus Muscle – Why does the back of my knee hurt? Part 2

As stated in my previous blog there are numerous reasons why manual therapist, trainers and athletes should consider the Popliteus muscle in the rehabilitative process. Here we will discuss some exercises which can be used to rehabilitate the Popliteus muscle.

Often people think rehab is about getting stronger and will do an old approach of taking a dysfunctional muscle and simply exercising it. The problem is rehabilitation isn't often about strength as much as it is about educating muscles. You can have the strongest muscles in the world but can get injuries if you dont teach them to fire properly or to work in the manner they should. The Popliteus is a great example of this concept as you never see people "working out" their Popliteus.

As mentioned previously the Popliteus is a muscle used mostly for kinesthetic awareness and stability in the knee. When an athlete pivots quickly or changes direction the Popliteus is put to work. When observing the picture below you can see how the muscle acts as a connection between the medial and lateral knee structures.

This means as the medial compartment experiences tension and the lateral side experiences compression the Popliteus receives this sensory feedback and stabilizes the knee. The opposite is also the same when the lateral side experiences tension and Medial experiences compression. This type of interaction occurs in the knee constently as an athlete brings the knee from flexion to extension and when performing pivoting moves.

So we need to rehabilitate it in a way that allows it to learn this function. However, how do you teach this function without putting stresses on the knee in an injured patient?

Exercises for the Popliteus

Exercises should consist of non-weight bearing and weight bearing exercises.

1. Using a resistant band attach one end to a stable service and the other around the forefoot of the affected leg. Using a wall for support begin the exercise with the affected leg unsupported at the patients side. From the start position begin flexing the knee and bringing the foot behind the stance leg as if attempting to touch your toe to your opposite hip. This creates flexion of the knee and internal rotation of the tibia. This motion will contract and activate the Popliteus. Now return to the starting position slowly to also train the Popliteus to contract eccentrically as well.

2. Stepping task - This exercise is used for progression and performed to challenge the Popliteus in a more functional manner. Using a small step up place one foot on the step allowing the knee to be maintained in a slightly flexed position. With the opposite leg off of the step bring yourself to a fencer type of stance.

Now while maintaining the supported knee in flexion begin different stepping manouvers. First going to 3 oclock back to start, 12 oclock and then 9 oclock. This exercise trains the Popliteus on how to prepare for cutting motions which will involve a forceful planting of the foot and manoeuvring in different directions.

The exercise can be further challenged by using verbal or visual cues to create a spongtanoise stepping action as apposed to the patient knowing where they will be going. Tossing a ball or using a racket can also make things more sports specific depending on the athlete. In addition, one can challenge the exercise by adding a blindfold to remove visual stimulus.

Once a patient displays proper technique in this exercise they may now progress to the same exercise above but using an unstable service.

3. Stepping Task Unstable Surface

4. The last exercise is done to train the Popliteus in a manner that challenges it to receive tension and then create a reflexive contraction. This involves a series of jumping task using pylons.

Standing alongside a pylon with one foot supported the patient jumps to the opposite side. The patient now has three options upon landing.

a) Land on the opposite leg they took off from allowing the Popliteus to be trained concentrically
b) Land on the same leg they took off from allowing the Popliteus to be used in a concentric to eccentric manner
c) Do option b followed by quickly jumping to the opposite side of the pylons allowing the Popliteus to be trained concentrically to eccentrically and then quickly concentrically again. This emulates a very quick stopping task or explosive take off manouver which man occur in multiple sports.

In summary, these are just a few quick exercises that can used in preseason training for athletes or any patient with knee problems. Dr. Wayne Button, BSc, DC

Nyland, J. (2005). Anatomy, Function, and Rehabilitation of the Popliteus Musculotendinous Complex Journal of Orthopaedic and Sports Physical Therapy DOI: 10.2519/jospt.2005.1414

Saturday, January 9, 2010

The Popliteus Muscle – Why does the back of my knee hurt?

The knee is one of the most complex joints in the human body. It is impossible to summarize such a topic with the understanding of only one muscle. However, certain muscles in the human body appear to be more important then others. With regards to the knee the Popliteus is one of these muscles. In this column I will attempt to explain the importance of the Popliteus Muscle in an injured knee and the rehabilitative process.

Anyone can open an anatomy textbook and retrieve the basic information about a muscle so how about I save you some time?

Popliteus Muscle:

O – Lateral Surface of the lateral condyle of the femur
Attachment to the lateral meniscus
I – Upper part of the posterior surface of the tibia
A – Medial rotates the tibia
Inn – Tibial Nerve (Moore, 2006)

Basic anatomy has its importance but to truly understand injuries one has to grasp the concept of muscles working in synergy together. Sometimes this ideology is referred to as the Kinetic Chain.

Some of the most important anatomical aspects of the Popliteus muscle will not be found in your basic textbook but in research. The Popliteus muscle is one of the most researched muscles in the knee and is always being debated upon its main role. Here are some important anatomical concepts you should know.

1. The Popliteus muscle plays an important role in “unlocking” the knee joint. When flexion and extension occurs the Popliteus is involved in rotating the Tibia and Femur. This action allows the two bones to deviate from one another and now the bones will not “collide” or “lock”. This mechanism leads to a smooth movement of flexion and extension throughout the knee.

This gives good indication to the importance of soft tissue therapy to the Popliteus muscle. When patients present with injuries that don’t allow a smooth or full range of motion the Popliteus muscle could be the culprit. With a knee that is “catching” the Popliteus muscle should be “released”. Releasing the Popliteus muscle can be done with heat, stretching, Myofascial Release Therapy, Active Release Technique or Graston Technique. (Manual Therapy Techniques)

2. The Popliteus muscle is what we call a “feed forward” muscle. Other “Feed Forward” muscles include the Multifidus in the back and Supraspinatus muscle in the shoulder. These are muscles that can actually “turn on” or “fire” before movement even occurs amongst the joint. Furthermore, these muscles have a high amount of receptors making them very important for proprioception and balance training. This is important to know because any patient who has an “unstable” joint or a past knee dislocation can vastly benefit from a rehabilitative program which exercises the Popliteus muscle.

In addition, this knowledge is a good indication that athletes may benefit from a preseason exercise routine, which involves the Popliteus muscle. By training a muscle involved in proprioception this may lower the incidence of knee injuries. This same concept is already being explored with preseason prevention of ankle injuries and acl tears by certain workout regiments.

3. The Popliteus muscle also works in synergy with the posterior cruciate ligament (PCL). Anatomical studies have shown that by actually cutting the Popliteus muscle tension increased in the PCL. The same is true otherwise that by increasing the force through the Popliteus, tension has been lowered in the PCL. This concept makes sense when you observe the following picture. When you look at the Popliteus and PCL together they almost both make a hammack for the knee joint allowing the bones to rest on their surfaces. It makes sense that if you were to injury, tear or have one weak the other would need to support the load.

This details the fact that by maybe strengthening the Popliteus muscle PCL injuries would decrease. Furthermore, if you have a weak and dysfunctional Popliteus you may develop PCL insufficiency or obtain an injury in the future.

Need more details? The Popliteus also:
- helps in movement of the lateral meniscus
-Is involved in posteriorlateral stability of the knee
-Plays an important component in down hill running
-Has attachments to all of the following

–Distal MCL
–Fibular Head
–Lateral Meniscus

These are just a few concepts of why I believe the Popliteus is thee most important muscle of the knee. Even if the muscle itself is not injured addressing it may give significant results. The old concept of only treating what is injured is dead and understanding the body as a whole is starting to evolve.

So how do I exercise/rehabilitate the Popliteus muscle?
Tune in for a rehab protocol of the Popliteus next blog

Nyland, J. (2005). Anatomy, Function, and Rehabilitation of the Popliteus Musculotendinous Complex Journal of Orthopaedic and Sports Physical Therapy DOI: 10.2519/jospt.2005.1414