Protocol for Anterior Knee Pain

Application

Background

• delay in contraction of the Vastus Medialis Obliques (VMO) vs. the Vastus lateralis (VL)
• weakness of the VMO
• weakness of the Gluteal medialis contributing to increased q-angle and, as a conseuqense, poorer momentum for the VMO

Other factors could be stiffness of the hip, shortening of the psoas major and excessive pronation of the foot.
Conventional physical therapy methods like strengthening the VMO, taping the patella, co-ordinations training as well as electrical stimulation have shown fairly good results in treatment of this problem. Recently some indications of superiority of EMG biofeedback for treatment of this problem has been suported. (1; 2) This is probably due to the improvement of delay in the recruitment of the VMO in pateller tracking, (3) or the change of activity from the VMO from tonic to phasic (4).
These results put emphasis on the control and recruitment of the VMO prior to strengthening which is of course important as well. The EMG biofeedback is a great tool for rehabilitation of this problem because it gives the patient the opportunity to gain inner perception in the recruitment and timing when contracting the VMO/VL complex.

Examination with KineLive

The picture on the right side reveals proper electrode placement for the VMO-VL.
The VMO electrode should be placed at 80% on an imaginary line between the spina iliaca anterior superior and the medial joint space just in front of the medial ligament.
The VL electrodes are placed at 2/3 on the line from spina iliaca anterior superior to the lateral side of the patella. Place the active electrodes (+ and -) parallel to the orientation of
the muscle fibers on the involved leg.

Remember to put just a thin film of gel on the electrodes before placement, otherwise refer to the practical manual on electrode placement and signal detecting.
Now click the record button to keep reference to look at and evaluate later.

Next step is to look at some functional activities these could be (depending on the patient status):

• walking
• squatting
• one leg squatting 
•  walking up and down in stairs 
•  running 
•  jumping

The wireless EMG makes this comfortable and easy task to do.
For testing choose the movement or functional activity that best matches your patient’s problem.
Do more than one test movement to be sure to get a good picture of your patient problem.

Now stop the recording to look at the results of your examination.
Two parameters are the main interest here:
a) timing of muscle recruitment (figure 1, click for bigger image)

Figure 1

b) amplitude of the muscle contraction (spikes are selected (figure 2, click for bigger image))

Figure 2

In the example above (figure 1) the problem is a delay and weakness of the VMO vs. VL.
This is the most common problem but you could see the opposite with VL tendonitis (Ice-skaters!) If the timing and difference in muscle strength is in order, the problem is either not from muscular origin or the test task is too easy for the patient.
Use the scroll bar to browse through your rapport and increase the size of interesting areas with the magnifier on left (manual).

Training with KineLive

We can divide the training in four stages:

1) Muscle setting:

• Train isometric contraction of key muscles; in this case it could be VMO, or VMO in combination with the Glut. Med.
• It could be helpful for the patient if you give resistance to isometric contraction in the beginning.
• Sometimes it is helpful in a standing position to put the hand over the gluteus medius on crista iliaca and contract the gluteii in combination with the contraction at the knee.
• It is of course possible to put an electrode at 50% on the line from crista iliaca to trochanter major to get signal from the gluteal medius muscle as well.
• Use the Visual Feedback from the ‘set max’ bar to enhance the awareness of muscle contraction on either VMO or Gluteus Medius.
  

2) Muscle control VMO vs VL in a simple movement.

• Choose appropriate movement like knee bending or stepping down from a platform to train the co-ordination. 
• Use the visual feedback ‘set max’ bar to enhance muscle contraction of the VMO and the ‘set min’ bar to withold contraction of the VL. (figure 3). 
• Choose absolute values from the right upper corner to monitor fatique of the muscles. Pause if you are not able to reach desired contraction of the VMO. 
• Stop the recording and look at the result. 
• You may have to repeat this session several time before you get results, and can move to the next step.
  
  Figure 3

3) Muscle control VMO-VL in a more complex movement.

• Some athletes need more challenge before symptoms are provoked. 
• Here you can for instance put the patient on a treadmill and run up hill or down hill at different speeds or you could choose sequence like running –jumping-landing, or jumping from hight and up again.
• You should especially monitor the muscle recruitment at landing and take off. 
• It could be important to look at the recruitment of VMO vs Semitendinosus as well. 
• In these situations it is beneficiary to connect a projector to the PC to have a bigger screen. 
• Because of the wireless technique you can move around in your gym to test various combinations and exercises. This is great because you can mimic the conditions from real situations of your patient.

4) Weaning off

• It is important to wean the patient from the biofeedback. 
• Let the patient work without looking at the pc. 
• Use the Audio alarm (drums) to give signal for good performance 
• Record the exersise or follow on the screen as appropriate. 
• Weaning off is also beneficiary after stage two.

Training with KineLive is both fun and easy! It is an exciting training tool that gives great motivation for the patient. The results of training with biofeedback are scientifically proven. Lately there have been published some articles stating the superiority of bio-feedback over other conventional methods and some are sited below. Otherwise I refer to the litterature for patellar tracking problems and biofeedback training in general.

References

2) Yip SL, Nq GY.  Biofeedback supplementation to physiotherapy exercise programme for rehabilitation of patellofemoral pain syndrome a randomized controlled pilot study Clin Rehabil. 2006 Dec; 20(12) : 1050-7

3) Cowan SM, Bennell Kl, Hodges PW Crossley KM, McConnell J, (2001).  Delayed onset of Electromyographic Activity of Vastus medialis oblique relative to Vastus lateralis in subjects with patellofemoral pain syndrome.  Archives Physical Medicine and Rehabilitation 82: 183-189)

4) Richardson C, Bullock MI. (1986). Changes in muscle activity during fast, alternating flexion-extension movements of the knee.
Scand J Rehabil Med. 1986;18(2):51-8.,)

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