The Forum of Benfleet Running Club

Mike Mason · Joined: 02 Jun 2006 Posts: 891 Location: Hockley

Well you can all stuff your shinsplits, rolled ankless, ITB etc - get yourself a real man's injury,,,,,,, compress

Popliteus muscle and knee injuries - Chris Mallac digs deep to discipline the unruly popliteus
Knee pain Small muscle, big trouble
‘Bloody hell, don’t English physios know what a popliteus muscle is?’ cried one of my exasperated rugby clients on his return from a recent training squad with an international team. His frustration stemmed from the fact that for a while we had overcome his problem knee by (among other things) regularly massaging and de-toning the popliteus to improve his range of knee extension. Two weeks without treatment and he soon learnt to appreciate the value of this small but problematic muscle. And his irritation triggered this thought in me: is it possible that not all sports therapists appreciate the significance of the popliteus? Read on, and prepare to be converted.

Anatomy
The popliteus is a small muscle that runs in the posterior (back) part of the knee. It is much smaller than the hamstrings and gastrocnemius. It is deep down and hard to find, and for the most part is considered an inconsequential muscle that rotates the knee.

The popliteus tendon originates on the lateral surface of the lateral femoral condyle (in front of and below the lateral collateral ligament origin) and also from the fibular head. It also has an origin stemming from the posterior horn of the lateral meniscus. The tendon then courses under the lateral collateral ligament, descends into the ‘popliteal hiatus’, and becomes extra-articular (outside the knee joint) before joining its muscle belly. It inserts into the tibia above the popliteal line. It is therefore a relatively horizontal muscle lying deep in the back part of the knee.

Functions
The popliteus is believed to have a number of functions, made possible by its unique ability to reverse its origin and insertion, depending on whether the femur or the tibia is fixed.

Internal rotation of the tibia in an already extended knee. Due to the contour of the femoral condyles, this internal rotation of the tibia ‘unlocks’ an extended knee. In essence it initiates knee flexion.
External rotation of the femur on a tibia that is fixed, as in the stance phase of gait. It is an important controller of knee rotation during the stance phase of locomotion.
Helps to bring the knee out of a position of full extension.
Helps the PCL (posterior cruciate ligament) maintain stability by preventing excessive posterior translation of the tibia.
Helps to withdraw the lateral meniscus during knee flexion.
Provides some rotary stability of the femur on the tibia.
Prevents excessive external rotation and varus rotation of the tibia during knee flexion.
Mechanism of injury
Acute trauma: Car accidents and falls with the knee extended are the most common causes of damage to the postero-lateral corner of the knee. Another mechanism is forced hyperextension and varus of the knee. Severe PCL injuries and even occasionally ACL injuries may involve a tear to the popliteus tendon;

Chronic overuse: Excessive use of the popliteus due to poor biomechanics, running surfaces or poor training progression can lead to tendinitis of the popliteus;

Reactive muscle tone: This is due to knee pathology. This is the nitty gritty of popliteus problems and the focus of this article.

Reactive muscle tone
In short, a popliteus that is tight and in spasm will cause a number of problems. The most significant of these is lack of full knee extension and lack of external rotation of the tibia on the femur. Both these movements will be affected by a tight popliteus that has a high resting and active level of muscle tone. Why does the popliteus exhibit increased reactive muscle tone? There are three main possibilities:

a. Reactive to knee joint pathology
It is common to see a popliteus (among other muscles) that is tight and in spasm following knee joint surgery. This may be caused by a structural operation such as an ACL reconstruction or a simple meniscal debridement. The effect is that the knee will have difficulty in fully extending and have poor initial resistance to movement with external rotation of the knee joint while in an extended position.

The most plausible explanation for reactive tone in the popliteus is the presence of a knee-joint effusion. Studies using intra-articular injections of saline into the knee show that the quadriceps, in particular the medial quadriceps, will become inhibited if the knee joint capsule is distended(1).

It is argued that the swelling in the joint capsule depresses reflex motor-neuron excitability. It is also possible (although there are no studies on this) that the popliteus may exhibit increased motor-neuron excitability to hold the knee in slight flexion and internal rotation in the presence of swelling inside the knee joint. Stratford(2) demonstrated that effusion-induced inhibition is less if the knee joint is slightly flexed. Reactive tone in the knee flexors such as the popliteus will keep the joint out of its close packed position of full extension and external rotation.

b. Compensation for poor quadriceps function
The popliteus may also become overactive in the presence of a poorly functioning quadriceps muscle group. A key role of the quadriceps is to control posterior tibial translation during movement. This is particularly evident in a knee that is PCL deficient.

The most likely reason for a poorly functioning quadriceps is inhibition caused by a knee joint effusion (see above) and/or knee pain. This is possible in a range of pathologies including post-surgical, patellofemoral problems and patella tendinopathy. In these cases, the popliteus may become quite overactive to help maintain posterior stability.

c. Compensation for poor rotary control by the hamstrings
The hamstrings group is the main torque producer for knee flexion. It helps control tibial rotation during the stance phase of gait. The lateral hamstrings (biceps femoris) actively externally rotate the tibia on the femur but also control internal rotation of the tibia on the femur in stance phase of gait. The medial hamstrings (semitendinosus and semimembranosus) control external rotation of the tibia on the femur in stance phase of gait.

A poorly functioning hamstring due to weakness or pathology may result in a compensatory overuse of the popliteus to control tibial rotation in stance phase.

Management of the popliteus
Assessment: It is hard to identify the popliteus as a source of dysfunction through routine clinical assessment. The patient may complain of posterior knee pain/tightness and/or a knee that does not want to fully straighten. They may also complain that the posterior part of the knee ‘blocks’ up with full knee flexion such as deep squatting, often leading the clinician to make a false positive diagnosis for a posterior horn meniscal tear.

On examination the knee may appear to have a slight lack of passive extension but more importantly, the knee will have a harder end feel to passive extension by the therapist. The knee may also demonstrate a firmer end feel with external rotation in extension. Furthermore, the knee may feel blocked with full flexion on a McMurray’s meniscal test.

Seated ‘figure 4’ (foot resting across opposite knee) positions will highlight the popliteus that has a tendinitis, but not necessary be positive in a muscle that is suffering increased tone. Another neat assessment idea is to feel passive external tibial rotation while in flexion, for example sitting with the feet dangling off the floor.

Other than that the therapist must get the patient prone and have a feel of the tone in the popliteus. This is best done with the knee flexed 20 degrees and passively supported. This takes away the tension in the gastrocnemius that may hide the popliteus.

Treatment: The best way to treat increased tone in the popliteus is through direct hands-on massage and ischaemic pressure. The popliteus is a very difficult muscle to stretch and will respond a lot better to hands-on treatment.

Direct massage is best done with the knee slightly flexed, as mentioned above. The bulk of the muscle belly lies in the postero-medial part of the knee under the medial gastrocnemius. Flush massage from medial to lateral tends to work best.

Direct pressure therapy is also best done with the knee slightly flexed. This will feel very uncomfortable to the patient and the therapist must be very wary of excessive pressure in the popliteal fossa, as some important nerves and blood vessels course through and down between gastrocnemius.

References
Young et al (1987). Effects of joint pathology on muscle. Clinical Orthopaedics and Related Research 219; 21-27.
Stratford P (1981). Electromyography of the quadriceps femoris muscles in subjects with normal knees and acutely effused knees. Physical Therapy 62; 279-283.

Behind Problem Knees: The Popliteus Muscle
By James P. Kotorac, D.C.

The popliteus is a small muscle that runs behind the knee. Due to its small size compared to the hamstrings above and the calf below, it is often overlooked in knee and lower leg injuries. It also isn't a very strong muscle, which adds to its relative obscurity. It is, however, of paramount importance to athletes. The popliteus has three basic motions. It helps to flex the knee, in fact, it begins the motion of knee flexion, actually unlocking the knee from full extension. In relation to this motion, a tightness or shortening of the popliteus inhibits full extension of the knee, leaving the knee unable to fully straighten.

Another motion is laterally rotating the upper leg on the lower leg when the foot is planted. For a runner, this becomes critical as a balanced gait is only achieved when this muscle is functioning properly. The final motion is medially rotating the lower leg under the upper leg. In running this would occur when the foot of that leg is in the air, powering toward the next foot strike. Shortness of this muscle would lead to an improper foot plant and excess pronation.

Injury occurs in two ways:

Any acute sprain/strain to the knee will involve the popliteus muscle.
Chronic overuse/ imbalance stress will also injure the muscle.
When the lateral hamstrings are stronger than the medial hamstrings, the popliteus muscle will weaken. Overpronation or running in worn shoes will cause excessive lower leg rotation and overstress the popliteus. A common practice among runners is hanging out or walking around in old running shoes. While you may be running in a good neutral position, the rest of the day you can be adding stress to the popliteus and the rest of your body as well.

The most effective treatment to an injured popliteus is manually applied trigger point therapy and ultrasound. While many muscles respond well to self-applied rubbing or kneading, the popliteus muscle should be approached with care. It overlies the popliteal fossa which is loaded with sensitive blood vessels and nerves where damage via too much pressure is possible.

The popliteus muscle is slightly stretched when the hamstrings are stretched. To strengthen the muscle, sit on a high chair with your legs dangling off the ground. Using elastic tubing anchored at one end, wrap the other end around the inside of your foot and rotate your foot and lower leg inward. Use low resistance and high repetition, remembering that this is not a powerful muscle.

Examination and, if necessary, treatment, therapy and strengthening of the popliteus should occur after any knee or ankle injury, lower leg break, or after any knee surgery. Here the popliteus' lack of strength is an advantage. Treatment restores this muscle to normal in a relatively short time compared to other larger and stronger ones. But don’t let its size and strength fool you. A popliteus problem can cause severe enough knee pain that running can become impossible.

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To Investigate the Anatomy and Function of the Popliteus Muscle
David Bryde, Linda Khong, Palina Karakasidou, Nessa Waters, Michael Wong
Clinical Implications
The popliteus muscle contributes to the movement of knee flexion (Williams et al 1995). It also initiates and maintains internal tibial rotation during gait, thus maintaining knee rotary stability (Basmajian and Lovejoy 1971, Fulkerson and Gosling 1980, Mann and Hagy 1977). Harner et al (1998) report that it acts synergistically with the posterior cruciate ligament (PCL) to help prevent forward translation of the femur on the tibia.

There are various popliteal pathologies, such as tendon subluxation (Crites et al 1998 and McAllister and Parker 1999), popliteus tenosynovitis / tendinitis (Howard et al 1992 and Mayfield 1977) and myofascial pain syndrome (Travell and Simons 1999).

There are two main palpation tests for diagnosing popliteus pathology. Bruckner and Khan (1999) and Travell and Simons (1999) have described palpation of the muscle belly posterolaterally at the knee joint in 30° of knee flexion. Griffin (1984) and Mayfield (1977) describe palpation of the tendon immediately anterior to the LCL in 90° of knee flexion with the hip abducted, laterally rotated and flexed. In the present dissection, it was not possible to support the validity of the latter test, as the tendon was deep to the LCL.

The authors consider that the popliteus muscle could contribute to rehabilitation of a PCL lesion. The PCL is placed under tension with posterior translation of the tibia and deep knee flexion (Garrett et al 2000). As the popliteus muscle internally rotates the tibia and helps to reduce its posterior translation, the authors propose that strengthening of the popliteus muscle will help to decrease tension on the PCL during loading. This would be especially important following a PCL reconstruction. The proposed procedure for strengthening of this muscle would be knee flexion, with resisted tibial internal rotation. This could be achieved in a sitting position with the knee flexed to approximately 90 degrees, with resisted tibial internal rotation by means of ‘theraband’ being placed around the foot. It is important that the medial hamstrings are not activated during this movement, as they will produce a posterior translation of the tibia, thereby tensioning the PCL. This is achieved by using the fingers to palpate the medial hamstrings as a means of biofeedback for hamstring inhibition.

It is well documented that popliteal muscle/tendon injuries occur most frequently with downhill running or walking (Garrett et al 2000, Mayfield 1977, Travell and Simons 1999). This may be due to the repetitive use of the popliteus musculotendinous unit in preventing anterior translation of the femur on the tibia, as popliteus muscle activity is proportional to increased load on a flexed knee (Davis et al 1995). The authors propose that strengthening of the popliteus muscle, as previously discussed, will strengthen the musculotendinous unit and thereby minimise trauma during downhill running activities. Many athletes use hill running as a functional lower limb strengthening exercise, and we believe that strengthening of the popliteus muscle may prove valuable in preventing injuries in this population.

Strengthening of the popliteus muscle could also be beneficial for people who have genu recurvatum. This condition can sometimes be painful in adults and children. The authors propose that decreasing the posterior translation forces of the tibia by increasing the strength and tone of this muscle could reduce pain levels in this population.

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Its everyone's lucky day since in my transition from swimming to tris I had every running injury in the book (I'm not really exaggerating). The popliteal tendinitis is probably deep hamstring problems. The root cause is probably a combo of the cambered roads (try running the lagoon trails by the Lomas Santa Fe train station -they connect to the trails in Rancho) and hip/knee muscle imbalance.

I would recommend as much trail running as possible because the uneven landing forces you to build stablizer muscles. Also, do a little single leg strenth training (lunges off a half ball, single leg squats, etc). They will build stablizers and help teach the muscles to fire properly. For the IT band strengthen vastus medialis (bump of muscle on the inside of your knee). Use the seated leg extension machine (actually ONLY for this purpose if you value your knees). Use low weights (start around 10) and do one leg at a time. You should mostly activate the quad muscle on the inside of your knee. Do sets of 12-20 reps with the leg turned 30deg outward. This will help balance the muscles around the kneecap. You can also do reps without weights while sitting in a chair at home or work. I *try* to lift about 2xweek but 15min a day of this stuff will do wonders. You can get a physio ball at home.

Fortunately for you H20Chica, I'm was an SD local until recently. I know a FANTASTIC sports massage therapist in Encinitas. He did wonders for my IT band tendinitis in 2001. Call 760 634-3701 and ask for an appointment with Richard. (The facility is Elite Care Chiropractic). I also know a PT in La Jolla and Mission Valley that has done a lot of work with me on hip stability (gino@functionsmart.com, functionsmart.com). He also does active release which is probably the only magic bullet I've ever come across. It hurts like hell but its a good, releasing kinda hurt. It breaks up the scar tissue and you walk away feeling better. I've found active release to be especially good for those persistent hamstring problems. A buddy of mine went to PT and massage therapists for 6months before seeing someone for ART and the sore hammys were back in a few days.

For immediate relief and prevention, I'm a huge fan of epsom salt baths. Also, I use Ben Gay patches on trouble spots. (Especially effective for calves). There is some new mixture of menthol and arnica gel out called "black and blue" that is growing on me. Its avaliable at Nytro.

Good luck, poor injured souls. PM me with any questions.

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If there is one area that always comes in for a bashing when people run, it is the knee. Ironically the knee joint is actually rarely the problem and the fault often lies in the joints above and below the knee. Unfortunately the knee is between the ankle and the hip, two areas where people often lack the necessary stability (in and mobility to create good movements.

Over time imbalances start to develop as muscles begin to take on jobs that they are not intended to do, which can lead to inflammation and injury, and it sounds like this may be the problem in this case. When we run there is an increase in the amount of load that has to be absorbed by the body of up to 3 – 4 times our bodyweight. Combined with the large amounts of mileage that people often put in while training for a marathon and you have ideal conditions to reveal any poorly functioning muscles and movements. Rest and symptom reduction through ice and painkillers will help alleviate the pain, but they won’t make the problem go away. You will need to get an actual diagnosis on the injury from a physiotherapist who can perform an analysis of your running style and check out your muscle function, although it sounds like you might well have a problem with a little known muscle called the popliteus. The popliteus is a small muscle that is at the back of the knee joint and it is often the source of pain in runners. The good news is that this condition can be remedied by treatment from a physiotherapist, osteopath, or an active release therapist (find one at activerelease.com).

It also sounds like your hamstrings (the large muscles that run from the hip down the back of the thigh) are taking on more than their fair share of the work when you are running. This is actually quite a common problem as these muscles are somewhat prone to getting overworked. While the hamstrings should be helping out during running, they are not ideally placed to be doing all the work of extending the hips, which needs to be done by the muscles of the backside. Stretching of the hamstrings can help relieve this, but you should combine it with strengthening exercises for the buttocks. You must also ensure you warm up thoroughly when training.

Stretch the hamstrings by lying on the floor with one leg straight and the other pulled toward the chest. Slowly extend the foot towards the ceiling until you feel a stretch in the back of the leg. Ease into the stretch and hold for 2 – 3 seconds, repeating this ten times on each leg. To strengthen that backside, lay supine bending both knees to ninety degrees with the feet flat on the floor. Keeping the abdominals tight and the pelvis in a neutral position, squeeze the bottom and lift the hips off the floor. Hold for 2 seconds and then lower, repeating for 15 – 20 repetitions for up to 3 sets. Once you have mastered this you can progress onto exercises such as high step-ups to encourage the muscles to work as part of the whole body during movement.

_________________
'sometimes I am running so fast it appears that rocks and trees are standing still......' 'I may be slow, but you are ugly and I can train harder.' '90% is mental, the other half is physical'it's going to get a lot worse, before it gets worse'.

mikemoreton · Joined: 23 Apr 2007 Posts: 502 Location: Hockley, GORC.

*yawn*

MM1,

Should i still go to benfleet physio, or stop running and get fatter, scoffing all the biscuits?

Karl C · Joined: 11 May 2006 Posts: 1539 Location: Rayleigh

will the real Mike Mason please f*ck off, please f*ck off..
will the real Mike Mason please f*ck off, please f*ck off..

will the real Mike Mason please f*ck off, please f*ck off..

will the real Mike Mason please f*ck off, please f*ck off..

will the real Mike Mason please f*ck off, please f*ck off..

will the real Mike Mason please f*ck off, please f*ck off..

Mike Mason · Joined: 02 Jun 2006 Posts: 891 Location: Hockley

Typical...I try to be constructive and offer advice and.................
_________________
'sometimes I am running so fast it appears that rocks and trees are standing still......' 'I may be slow, but you are ugly and I can train harder.' '90% is mental, the other half is physical'it's going to get a lot worse, before it gets worse'.

Karl C · Joined: 11 May 2006 Posts: 1539 Location: Rayleigh

I was going to say GET LOST.......but even I'm not that childish....

anyway, where the feck is our shortbread !

mikemoreton · Joined: 23 Apr 2007 Posts: 502 Location: Hockley, GORC.

Karl,

that has to be of your better comments/questions

Where IS the shortbread?