Overcoming and Preventing Knee Pain

Clinical Study of the Role of the Vastus Medialis and its Importance within Overcoming and Preventing Knee Injuries

Nick Doughty, CES, TRI, PES, CPT, PICP


"Over the last century great strides have been made in the physical medicine and training fields. Manipulative techniques for joint dyskinesia have become refined and specifically advanced. Training and treatment methods have become more scientific. Now, as we enter the 21st century, the world is seeing rapid advances in the field of functional neurology. Methods for correction of aberrant neurological control and muscle performance enhancement are quickly rising to the forefront of current treatment and training approaches. This area "neuroplastic" treatment and training is now receiving recognition for the critical role it plays in complete treatment and training methods. In creating and utilizing a neurosummative methodology, Trigenics® enables enhanced stimulation of neurological pathways for a spinal and brain-based results effect which are unparalleled."

Dr. Allan Gary Austin Oolo, 2000 [11]

The knees are the most easily injured part of the body despite not being the most structurally complex. The Knee is the largest of joints and is used in everything from sitting to standing, walking to running and makes it more susceptible to the risks of acute or overuse injuries as its a weight bearing joint that works in all three planes of movement (Saggital, Frontal and Transverse).

Acute knee injuries (including torn ligaments and torn cartilage) are often caused by twisting the knee or falling. Sports that involve running and jumping and sudden stopping and turning, such as football, rugby, tennis and also includes contact sports such as hockey increase the risk of an acute knee injury. [12]

But more common than sudden knee injuries are injuries caused by overuse and include muscle strain, tendonitis and bursitis, and can develop gradually over days or weeks. Pain is often mild and intermittent in the beginning and worsens over time. When muscles and tendons are stressed even slightly beyond their capabilities, microscopic tears occur. (Inflammation, which is part of the healing process, is what causes the pain). Knee pain is commonly caused by doing too much too soon when you haven't exercised for a long period of time - especially high-impact aerobics; walking, running or jumping on hard surfaces or uneven ground; excessive running up and down stairs (When you walk upstairs you are putting pressure on your knees that is equivalent to four times your body weight, when running up the stairs it can be eight times your body weight).[2]

Anatomy of the Knee

The principal knee movements are flexion and extension with a degree of rotation possible when this joint is in the flexed position (standing). In full extension the knee is rigid because the medial condyle of the tibia is larger than the lateral condyle and will ride forward on the medial condyle of the femur thus screwing the joint in a firm position and fully activates the lower portion of the VMO. The unscrewing of the knee comes about when the popliteus unlocks the knee from the lateral side of the femur and inserts into the upper end of the tibia.

The knee joint's main function is to bend and straighten for moving the body. The knee is more than just a simple hinge. It also twists and rotates. In order to perform all of these actions and to support the entire body while doing so, the knee relies on a number of structures, including bones, ligaments, tendons, and cartilage.

The knee joint involves three bones, The thighbone or femur comprises the top portion of the joint and the tibia, provides the main supporting structure for the bottom portion of the joint. The third bone considered to be the patella or knee cap.

Ligaments are fibrous bands that connect bones to each other, the knee comprising of four main ones, all four of which connect the femur to the tibia: The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) provide front and back (anterior and posterior) and rotational stability to the knee.

The medial collateral ligament (MCL) and lateral collateral ligament (LCL) located along the inner (medial) and outer (lateral) sides of the knee provide medial and lateral stability to the knee.

Tendons are fibrous bands similar to ligaments but instead connect muscles to bones. The two important tendons in the knee are (1) the quadriceps tendon connecting the quadriceps muscle, which lies on the front of the thigh, to the patella and (2) the patellar tendon connecting the patella to the tibia (contradictorily this is actually a ligament as it connects bone to bone).

The quadriceps and patellar tendons as well as the patella itself are sometimes called the extensor mechanism, and together with the quadriceps muscle they facilitate leg extension (straightening).

Cartilaginous structures called menisci (one is a meniscus) line the top of the tibia and lie between the tibia and the two knuckles at the bottom of the femur (the femoral condyles). Menisci provide both space and cushion for the knee joint. Bursae (singular is bursa) are fluid-filled sacs that help to cushion the knee. The knee contains three important groups of bursae.

- The prepatellar bursa lies in front of the patella.
- The anserine bursa is located on the inner side of the knee about 2 inches below the joint.
- The infrapatellar bursa is located underneath the patella. [8]

Acute or chronic trauma causes a painful and often swollen knee from the inflammation of the bursae. A particularly common bursitis is prepatellar bursitis. This type of bursitis occurs in people who work on their knees. It is often referred to as housemaid's knee or carpet layer's knee. Another type of bursitis is anserine bursitis. The anserine bursa is located about 2 inches below the knee along the medial side of the knee. Though it occurs more commonly in the overweight and in women, it also affects athletes and others. Anserine bursitis often causes pain in the region of the bursa and is often worse with bending the knee or at night with sleep.

Despite this problem being situated around the knee I have ruled this out a having any interference of the firing of the VMO. Increased risk of knee injury (chondromalacia) occurs during knee extension activities that surpass 30 degrees.[2]

A Delayed response of VMO to the VL's Onset Timing Contributes to the development of Patellofemoral Pain in Previously Healthy Men[3] caused when the patella becomes laterally displaced with the pull of the Vastus Lateralis. This patella tracking problem can produce wear on the inferior patellar surface. Greater pain is usually experienced during leg extension activities in which the knee is a greater than a 20 to 30 degree angle. Avoiding full range of motion (i.e. not locking out) during Quadricep exercise may not allow the Vastus Medialis to be fully strengthened since it is more fully activated between the final 10-20 degrees of knee extension[5].

Patellofemoral syndrome (PFS): The commonest cause of chronic knee pain, PFS characteristically causes vague discomfort of the inner knee area, aggravated by activity (running, jumping, climbing or descending stairs) or by prolonged sitting with knees in a moderately bent position (the so-called "theater sign" of pain upon arising from a desk or theater seat). The knee may be mildly swollen. If chronic symptoms are ignored, the loss of quadriceps strength may cause the leg to "give out."

PFS is caused by an abnormality in how the kneecap (patella) slides over the lower end of the thigh bone (the femur). Normally, the patella (kneecap) is pulled up over the end of the femur in a straight line by the quadriceps (thigh) muscle. In PFS, there is patellar "tracking" toward the lateral (outer) side of the femur. This off-kilter path permits the underside of the patella to grate along the femur leading to chronic inflammation and pain. Females are at greater risk than males for PFS.

Knock-kneed and flat-footed runners and persons with an unusually shaped patella are predisposed to PFS. Initial pain management is icing, anti-inflammatory drugs and avoiding motions which irritate the kneecap. Treatment and rehabilitation are designed to create a straighter pathway for the patella to follow during quadriceps contraction. Selective strengthening of the inner portion of the quadriceps muscle helps normalize the tracking of the patella. Cardiovascular conditioning can be maintained by stationary bicycling (low resistance but high rpms), pool running, or swimming (flutter kick). Changes in training that may have led to the PFS pain should be reviewed and running shoes examined for proper biomechanical fit to avoid repeating the painful PFS cycle. Occasionally bracing with patellar centering devices is required. Stretching and strengthening the quadriceps and hamstring muscle groups are essential to an effective and lasting rehabilitation of PFS. "Quad sets" are the foundation for such a program and are done by contracting the thigh muscles while the legs are straight and holding the contraction for a count of ten. Sets of 10 contractions are done between 15-20 times per day. Under optimal circumstances, there should be a rapid recovery and return at full functional level to sports. Iliotibial band syndrome

Description: A fibrous ligament, called the iliotibial band, extends from the outside of the pelvic bone to the outside of the tibia. When this band is tight, it may rub against the bottom outer portion of the femur (the lateral femoral epicondyle). Symptoms and signs: Distance runners typically suffer from this condition. These runners complain of outside knee pain usually at the lateral femoral epicondyle. Early on, the pain will typically come on 10-15 minutes into a run and improve with rest.

Treatment: The most important aspect of treating iliotibial band syndrome is to stretch the Iliotibial band. One way to do this is to place the right leg behind the left while standing with your left side about 2-3 feet from a wall. Then, lean toward your left for 20-30 seconds using the wall to help you support yourself. In addition to stretching the iliotibial band, PRICE therapy and NSAIDs may be of some help.

The purpose of this particular and independent study was to selectively challenge the role of the vastus medialis oblique muscle in comparison with other quadricep muscles when acting upon injury stricken knees.

Several patellofemoral studies were included as the main focus was on the VMO and the exercises that recruit muscle fibres of the VMO. Patellofemoral pain is often the cause of muscle imbalance between VMO and VL or alteration of the timings of the muscles as stated by Herrington et al.

Researchers believe that if the Vastus lateralis fires first, the patella is prone to have maltracking problems, but if Vastus Medialis was to fire first this would not be the case.

The inclusion criteria for patellofemoral pain subjects included a diagnosis of patellofemoral pain syndrome, chronic knee pain for over a year, Pain free, missed at least one training session within two months, pain with resisted knee extension, pain squatting past 30 degrees, stairs, prolonged sitting, hopping or jumping, positive apprehension test, full range of motion or insidious onset.

The Inclusion criteria for the healthy subjects were no history of knee pathologies, full range of motion, no swelling and no patellofemoral pain syndrome.

The exclusion list for both parties consisted of pain on palpation of quadriceps or patellar tendon, snapping sensation at the knee, pain at joint line or trauma to the lower extremity (surgery, fracture or sublaxing patella)

The study was conducted in a clinical environment involving four different participants , all displaying signs of AKP. Forty people underwent all pre requisite tests including the Werner score test and patella glide test.

Each participant under went muscular length and strength tests of the quadriceps and hamstring and were subjected to patella glide test before hand to rule out pain upon palpation. Finding the location of pain is very useful to make diagnosis and plan treatment, with lateral retinaculum being the focus point with emphasis on the insertion into the patella [4]. The patella is divided into four longitudual quadrants and a medial translation of one quadrant is suggestive of lateral tightness and with this test pain will be elicited over the lateral retinaculum (Figure 1.1). Patellar tilt can also detect tight lateral recinaculum and should always be carried out (Figure 1.2). The knee is started in 30 degrees of flexion and quadriceps relaxed.In a normal knee, the patella can be lifted from its lateral edge farther than the transepicondylar axis, with a fully extended knee. Contradictoryto this a tilt of 0 degrees will indicate a tight lateral retinaculum. Lateral retinacular tightness is common in patients with anterior knee pain and a show-sign of lateral pressure syndrome (I.T Band Syndrome).

A patella grind test to rule out originating pain patellofemoral articular surfaces of the patella or trochlear subchondral bone. When this test is positive it shows that there is an increase in intraosseos pressure. [5] To perform the test the patella is bumped against the trochlea with the palm of the hand at various angles of knee flexion (Figure 1.3) Contact is made proximal to the patella and distal upon the femur, with any pain or crepitation being felt at approximately 90 degrees of flexion. Contradictory to this ant distal pain will be felt in the early degrees of knee flexion. Allen and colleagues have found that in patients with AKP, a significent association was noted between proximal patellar tendinopathy, palpation of the inferior pole of the patella should be carried out pressing downward on the proximal patella tendon (Figure 1.4)

Measurement of the Q-angle was noted on all participants, despite this not being a reliable indicator of patellar alignment. However I regard this as valuable information which might correlate with other findings to help understand misalignment problems.

Measurement was taken with the patient in a supine position, at approx 30 degrees of flexion. Normal readings for males is 12 degrees compared to that of 15 degrees for females. [13]

All participants completed a Werner Test Score for functional AKP and participants displaying signs and symptoms of knee pain scored each question between 0-3 (Figure 1.5).

All clientele showed imbalances between quadriceps and hamstrings with the semi membraneous showing a prevalent weakness in comparison to the lateral hamstring/ Quadricep muscles. Being that the medial Quadricep was also showing up weak I believe this to be poor reciprocal inhibition of the medial muscular structures and was dominant throughout all participants. Hypo trophy of the VMO is common in anterior knee problems, and is one of he most vulnerable muscles in the knee extensor mechanism. The pure powering size of the Vastus Lateralis muscle is what causes the unbalanced action of the quadricep component and closely linked to the patellar maltracking shown during knee extension when VM pulls the patellar first medically then proximally which is opposing to that of the VL muscle. [14]

The following muscles were palpated on all subjects;
- quadriceps
- hamstrings
- gastrocnemius
- I.t band

Soft tissue massage was performed on any of these surrounding musculature that required it as it has been noted in past clinical study's that there was a correlation to AKP.

Tightness of the I.T Band and T.F.L have shown to cause AKP, resulting in deviation of the patella laterally, with lateral tracking and tilt, usually also weakening the medial retinaculum.

Tight hamstrings, gastrocnemius or soleus can result in over pronation of the subtalar joint in the foot causing inwards collapse of the knee (valgus knee).

If there is an indication of tight gastrocnemius this can cause a lack of dorsiflexion and a decrease in the talocrural joint. Bio mechanically this can alter walking or running gait and cause the onset of many associated knee problems.

Each participant then completed one of the following strength tests depending on the severity and age of their injury;

  • Klatt test
  • Overhead Squat
  • Wobble board test
  • Rocker board test

Within these performances ALL 4 PARTICIPANTS showed signs of weak or tight VMO muscles.

The Participants then performed one of the following Vastus medialis specific strengthening exercises depending on the state of their injury and capability to perform:

Split Squats

  • Poliquin Step Up (Raise of 12 inches)
  • Cable Reverse Petersen (With 20 degrees of flexion measured by goniometer)
  • Weighted swiss ball single leg squat (With 20 degrees of flexion measured by goniometer)

Following the results that the participants obtained from their strength tests, a range of procedures were applied to each individual depending on the severity of their problem and the need for clinical attention:

  • Trigenics
  • Myofascial Release
  • Kinesio Taping
  • Fascial Abrasion/Muscle Stripping
  • VMO Specific Strengthening Exercises
  • Trigenics is a medical assessment and treatment system which uses interactive applied functional neurology to reset the way the brain communicates with the body. The result is that of immediate, dramatic pain relief with instant increase in strength and movement. A worldwide leading innovation in the field of functional neurology, Trigenics has revolutionised the way patients with musculoskeletal disorders and pain syndromes are treated.Founded by Dr. Allan Oolo Austin, Trigenics was the first in history to introduce the concept of combining muscle treatment with resisted exercise. The therapeutic neuroplastic effects of Trigenics are unprecedented![1]
  • Myofascial release is a form of soft tissue therapy used to treat somatic dysfunction, pain and restriction of motion. Using palpatory feedback to achieve release of myofascial tissues, accomplished by relaxing contracted muscles, stimulating the stretch reflex of muscles and overlying fascia response as well as increasing circulation and lymphatic drainage.
  • Kinesio Taping Method involves taping over and around muscles in order to assist and give support or to prevent overcontraction. The first technique gives the practitioner the opportunity to actually give support while maintaining full range of motion. This enables the individual to participate in their normal physical activity with functional assistance. The second technique, which is most commonly used in the acute stage of rehabilitation, helps prevent overuse or over-contraction and helps provide facilitation of lymph flow for an entire 24 hour period. Correctional techniques include mechanical, lymphatic, ligament/tendon, fascia, space and functional. Kinesio Taping can be used in conjunction with other therapies, including cryotherapy, hydrotherapy, massage therapy, and electrical stimulation [10]
  • Fascial Abrasion Technique involves the use of a tool to break down scar tissue and resolve fascial restrictions. Fascial abrasion technique is used to treat painful conditions resulting from injury or overuse disorders such as carpal tunnel syndrome, plantar fasciitis, cervical and lumbar strain, tendinosis (achilles, rotator cuff) patella-femoral knee pain and tennis and golfers elbow. [7]
  • Upon completing these procedures the clients then performed their exercise again. All participants succeeded in improving their previous score experiencing no knee pain whilst performing more repetitions and/or more weight.


    A number of anterior knee pain patients show signs of tight Iliotibial band and other lateral muscle structures. A lot of the stretches for this area can be performed by the patient themselves therefore I have instructed them on the best practice to do this. To end the clinical trial I also perform a particular stretch on all participants. In a side lying position on the opposite side with the symptomatic knee in approx 30 degrees of knee flexion, I then move the patella medically and tilt the medial border of the Patella posteriorly and stretch the lateral retinaculum.

    Furthermore to the clinical testing that took place I included balance and co-ordination exercises into the participants future training programme. Physical training causes changes within the nervous system that leads to nervous system that leads to improved co-ordination between muscle groups and regular practice results in automatics, which indicates a change and improvement in the motor program.

    When the activity and function of he VM has improved, balance and co-ordination training of the lower extremitys should be started. Balance and coordination exercises should preferably be performed during knee loading conditions and with slightly flexed knees in order to try to direct the training to the knee joint.

    Knee rehabilitation exercises that included isometric knee extension with the hip at neutral, 30° external, and 30° internal rotation; isokinetic knee extension through full range; isokinetic knee extension in the terminal 30° arc; sidelying ipsilateral and contralateral full knee extension; and stand and jump from full squat were given to strengthen the relevant Quadricep muscles.

    By improving the efficiency of the VMO muscles firing rate, this has been proved to be highly beneficial in the rehabilitation of AKP using Trigenics.

    This emphasises that the VMO is the main element in knee pain and by using Trigenics to structurally balance the knee through facilitated change on the nervous system, holding longer than just working on the muscles or joints. [8]