Anatomy

The Knee is a big hinge joint (though it is not a simple hinge joint). The knee cap slides on the groove of the thigh bone when the knee bends beyond 15 degrees. As the strong quadriceps muscles are attach on the knee cap and becomes the patellar tendon that coneects to the shank bone, pressure up to 3-5 times of the body weight is exerted on the square inch contact surface behind the knee cap.

Pathology

The knee cap sometimes will slide on the groove in a wrong track. One of the quadricep muscles (Rectus Femoris) runs from our pelvic in an oblique way. If the pelvic is too wide, or there is knocked knee (Genu Valgum), the angle of pulling the knee cap is more on the outward direction (that is called Q-angle). It leads to a tracking problem of the knee cap and the pressure in the joint is no longer evenly distributed, thus causing early degeneration of the cartilage.

Foot pronation is also proven to be a significant factor of this degenerative process. Excessive foot pronation may induce internal rotation of the shank bone and thigh bone, causing relatively more outward displacement of the knee cap. This phenomenon is more common in female since

1) Female has wider pelvic so that the Q-angle is larger.

2) Female has weaker core muscles and more internal rotation of the leg and thigh.

Treatments

Rest or avoid activities require bending of the knee.

Stretching of the quadriceps.

Strengthening of the Vastus Medialis Oblique (VMO) that helps to stablize the knee cap on track.

Surgical Options.

Biomechanics evaluation on the hip, knee and foot.

 

• Foot biomechanics plays an important role on patellofemoral syndrome. As the foot pronation causes collapse of the arch, it leads to excessive internal rotation of the thigh bone and more outward displacement of the knee cap. Knee alignment is also evaluated as knock-knee may place excessive pressure on the inner side of the foot, causing excessive collapse of the arch in weight-bearing condition.

Prevention

Proper training plan (Avoid running hills)

Core muscles training.

Stretching of the quadricep muscles in daily basis.

Avoid wearing high heels.

Biomechanics Insoles that maintain the good body alignment.

 

 

• Biomechanics Inosles helps to reduce excessive foot pronation (arch collapse) and thus prevent the thigh bone from the internal rotation, holding the knee cap in a more proper tracking in the groove of it.