An In-depth Review of Protonics and Knee Pain

Technological advances over the last 20 years have dramatically changed society. People now have more leisure time than ever before. Individuals are engaging in more sports and at an earlier age. It is not uncommon for a six or seven year old to be involved in two or three organized sports at the same time. This increased activity may carry over into adolescence and adulthood. This means a larger number of patellar-femoral dysfunction complaints are encountered. Patients with PFD have two primary complaints:

• Anterior knee pain.
• Decreased levels of activity and function.

This discussion will look at another way to describe, diagnose, and treat patello-femoral dysfunctions. Patello-femoral compression, a leading cause of patello-femoral dysfunction may be the result of other underlying circumstances. This will require a shift of thought, a paradigm shift. The discussion will look at how poor hip stability and posture affect the patella/femur alignment problem associated with PFPS and not how the patella is misaligned due to an imbalance in muscle strength.

While you will not find this information presented this way in any textbook, supporting evidence for everything that is discussed can be easily found in available textbooks or research articles that have been published and accepted for the last 15 to 20 years.

In order to share this with as many readers as possible, the report is written using easy to understand terminology. It is hoped that the reader will concur that this information contains new and exciting technological advances in the treatment of patello femoral pain.

Conventional Patello-Femoral Dysfunction Description and Treatment.
In its simplest form, PFD is described as misalignment of the patella on the femur. In addition to alignment, the dysfunction is also described as an abnormal movement of the patella (kneecap) on the femur (patellar tracking). This movement causes an excessive amount of pressure between the patella (kneecap) and the femur (thighbone). This pressure or compression causes the cartilage on the under side of the patella and the cartilage on the bottom end of the femur to start to soften, degenerate, and wear away (see Figure 1). If left untreated, the cartilage can be worn away completely. This is known as chondromalacia patella. It is generally accepted that this compression is most often due to an imbalance in the thigh muscles (quadriceps) strength. The muscles on the outside or lateral side of the patella (vastus lateralis) are too strong, the muscles on the inside or medial side of the patella (vastus medialis) are too weak, or a combination of both (see Figure 2). The result of this imbalance is a repositioning of the patella to the outside.

Traditional treatment for PFPS usually starts with an exercise program that concentrates on strengthening the vastus medialis. A special patellar brace, strap, or tape is usually the next step. Both the brace and tape are used to attempt to manually pull or push the patella back into its normal position. If these two forms of treatment do not work, surgery is sometimes recommended. A procedure known as a lateral release is the most common. It involves separating or releasing some of the fibrous tendon like material on the lateral side of the patella. The final option generally recommended is to have knee joint replacement surgery. However, physicians normally will not perform this procedure on patients unless they are 60-65 years of age. Artificial knee joints typically last a dozen or so years and the procedure can only be performed two to three times. Some patients will have to endure years of pain and suffering because of this.
The New Perspective:
Pelvic-Femoral-Patellar Alignment

In the diagnosing and treatment of patellar-femoral pain, the focus of attention has generally been an area six to eight inches above and below the knee joint. By concentrating on this small area, it seems as though the patella is being pulled into the femur. This new concept looks at the whole body for an answer rather than just the knee. Research has lead to the conclusion that a large percentage of PFD patients
have an instability in the hip and pelvis area


can trace their problems back to poor hip/pelvis posture (excessive lumbar lordisis). This biomechanical instability of the hip results when the pelvis is tipped forward. Many contributing factors can be linked to this condition. Forward head posture, weak abdominals, excessive weight, tight lower back muscles, tight groin muscles, weak muscles in the buttocks, and weak hamstrings (muscles on the back of the thigh) are just a few. In this pelvic position, the femur is repositioned inwardly. This repositioning can restrict a patients ability to flex the knee under a load due to lateral compressive forces of the femur on the patella. CYCLE

In a normal knee the muscles pull on the patella evenly. When the bone is out of place the contact points of the joint are changed. Thus the pressure on the normal points is changed. When the knee bends this additional pressure in the joint causes pain and or degeneration of the cartiledge on the back of the patella.

The ability to turn the leg in and out is called internal and external rotation respectivly.

The position of the pelvis and femur directly relates to the pressure that is causes muscles normally used for postural support and normal function to effectively shut down or become dormant. This forces other structures on the outside of the thigh to hold the body up. Two of these structures are the vastus lateralis (VL) and the iliotibial band (IT band). The VL is the muscle located on the lateral side of the quadriceps group of muscles. This muscle directly attaches to the patellar ligament on the lateral side. The patella is located just underneath this ligament and attaches directly to it. The IT band is composed of a fibrous tissue called fascia. It starts at the hip and runs down the lateral side of the leg. It also attaches to the patellar tendon/ligament (see Figure 3).

The kneecap actually may be in its "normal" position and the femur is the bone actually "misplaced" or turned in under the kneecap. This produces tightness of the VL and IT band.

PROTONICS®

When muscles are “turned on” other muscles need to be “turned off” in order for movement to occur. For instance, in order to bend or straighten the knee, two muscle groups need to work together. The muscles on the back of the thigh (hamstrings) cause your leg to flex/bend when they contract. The muscles on the top of the thigh (quadriceps) cause the leg to extend/straighten when they contract. In order for movement to happen, one set of muscles needs to contract while the other set relaxes. This is known as “reflex inhibition”.

Protonics™ applies a programmable and variable resistance during the flexing action of the knee. This resistance “turns on” muscles in the back of the thigh, buttocks, and abdominals. In response, each time the Protonics™ resistance is engaged, there are three main muscles that are “turned off”.
1. Psoas (pronounced "so us") This large muscle in the abdomen (lower back? abdominal cavity?) is attached on one side to the lower spine and to the femur just below where it (femur) inserts into the hip socket (see Figure 4. By shutting down this muscle, the muscles in the buttocks and abdominals stabilize the pelvis. As a result, the hip is rotated back into its normal neutral position.

2. Tensor fasciae latae (TFL). This muscle is located on the front of the thigh on the lateral side near the hip (see Figure 5). This muscle attaches to the hip and to the IT band. The TFL is the primary muscle used to rotate the femur inwards. If this muscle is turned off, the internal rotation of the femur is lessened.

3. Vastus lateralis (VL). As discussed earlier, this muscle attaches to the femur and directly to the patellar tendon on the lateral side. If this muscle is turned off the amount of lateral pull on the patella is reduced (see figure 5).

The result of these three muscles being effectively “turned off” is that:
1. The hip is in a more neutral position reducing the tendency for the femur to rotate inward.
2. The TFL is not rotating the femur inwards.
3. The femur is in its normal neutral position.
4. An appropriate femur–tibia–patella alignment during movement is realized.

The concept described above is why many patients report immediate pain relief when initially using a Protonics™ system. Patients may also benefit in the long term because Protonics™ provides a way for the body to learn how to correctly function again.

A process known as feed forward activation is used. Feed-forward activation is the process by which muscles “learn” how and when to contract or relax during certain phases of movement. This process happens on a neuromuscular level involving the muscles, nerve cells, brain, and other structures involved in the central nervous system. To describe in very simple terms, feed-forward activation is the ability of a muscle or group of muscles to learn a specific pattern of movement through repetition. By having a patient wear the system during functional daily activities in addition to when they are doing specific exercises, the muscles of the leg and hip are stimulated by the Protonics™ resistance programs over and over again. In time, these muscles will learn to anticipate this stimulus and therefore move in the correct manner even without the system.

Postural and functional dynamic demands placed on the lateral side of the knee (biceps femoris, vastus lateralis, IT tract) can be reduced through functional resistance applied to the hamstrings. Excessive internal rotation of the femur and tibia, into the patella, secondary to overuse of the psoas and biomechcanical instability of the hip (lumbar lordosis) creates high degrees of patello femoral compression. Patello femoral compression and pain is reduced through “feed-forward” activation of the hamstrings, obliques, gluts and abdominals and through reciprocal inhibition of the psoas, vastus lateralis, and tensor fascia latae. Programmable functional resistance applied to the hamstrings normalizes dynamic stability of the hip and reduces abnormal rotation of the femur on the hip. Appropriate femur and tibial axial alignment and position to the patella during active patella tracking is therefore experienced.

Below is a flow chart that visually explains how PFD develops and how Protonics™ resistance can relieve and retrain the pain and suffering associated with PFD.






Basic Anatomy
The femur has two knobs on the end. A very tough, but very slick cartilage covers these knobs. The tibia in contrast is more flat and has two pieces of cartilage called menisci (meniscus -–singular) attached to the end. The menisci have an outer con-cave surface that the 2 balls of the femur sit in. See fig. 3. The human knee does not bend like a hinge, it moves with a “slide and roll” type of bending. See fig 1. The patella sits just in front of and a little higher than where the femur and tibia meet. The patella is kind of triangular in shape when viewed from the side. It is lined with cartilage all along its underside. It is this shape that allows the patella to glide down along the femur and in between its knobs as the knee is being bent.

Over the top of the patella lies a tough ligament called the patellar ligament. This ligament provides the connection between the muscles on the front of your thigh (quadriceps) and the 2 bones in the leg (tibia, fibula). This connection allows you to extend your leg such as when you rise from a seated position. Because of the way the knee moves (“slide and roll”) and because of the ligament covering the patella, when the knee is bent the patella is pushed against the femur. See fig. 2. This compression is normal and is even necessary for the knee to remain stable. The problem occurs when the alignment of the bones in the knee is off.