People suffering from anterior knee pain/patellofemoral pain usually will benefit from proper strengthening, stretching, and alignment during functional activities.  But some people tend to continue to have discomfort at their knee even when those deficits are corrected.  There has been recent research showing that people suffering from anterior knee pain can also be from mechanosensitivity/hypersensitivity.

Continued irritation and swelling tends to promote blood vessel and nerve proliferation.  Also, nerves can eventually adhere to structures at the knee such as the bone, ligament, fascia, etc. from injury.  Treatment for improving neurodynamics at the femoral nerve, and associated medial and lateral patellar branches, around the knee can prove beneficial.

Two studies by Lin et al. and Huang et al. examined the use of the Femoral Slump Test to assess neurotension at the knee and other predictors that an individual might benefit from nerve tensioning/gliding.

Individuals that may benefit from this type of treatment are people with symptoms at the anterior knee at the knee cap during stair climbing, squatting, kneeling, or sitting for a long time.  They will also be positive for more than 2 of these clinical tests:

Clarke’s sign – The individual is supine with their knee extended and pressure is applied to the knee cap as they contract their quadriceps.  The test is positive if there is a reproduction of their symptoms.

Waldron Test – The individual is supine with their knee slightly flexed and pressure is applied to the knee cap the knee is progressively flexed more.  The test is positive if there is a reproduction of their pain or crepitus.

Active Patellar Grind Test – The individual sits with their knee at 90 degrees and the examiner palpates the knee cap as the individual straightens their knee.  The test is positive if crepitus is felt during the motion.

Patellar Compression Test – The individual is supine with their knee extended.  Their knee cap is compressed and shifted superiorly.  The test is positive is there is a reproduction of their symptoms.

Assessment and completion of nerve tensioning/gliding is not appropriate if the individual’s anterior knee pain is due to other pathologies such as meniscus, ligaments, etc.

The Femoral Slump Test should be completed with measurement of hip flexion bilaterally when symptoms come on.

The test is positive if the individual’s anterior knee pain is reproduced and then reduced or eliminated with extension of the head.  If the individual has a history of lower back pain and there is a difference of hip flexion during the slump (>3 degrees on the affected side) then the prediction that nerve tensioning/gliding is greatly improved.

The authors of the article completed tensioning of the nerve by taking the hip into extension in the Femoral Slump Test position until the individual’s anterior knee pain is  first felt  then held for 2 seconds.  This was completed 10 times for 3 sets.  Improvement of knee pain was seen on the first session in 50% of subjects and in all subjects by the sixth session.

References:

1. Lin PL, Shih YF, Chen WY, Ma HL. Neurodynamic response to the femoral slump test in patients with anterior knee pain syndrome. J Ortho Phys Ther. May 2014; 44(5):350-357.
2. Huang BY, Shih YF, Chen WY, Ma HL. Predictors for identifying patients with patellofemoral pain syndrome responding to femoral nerve mobilization. Arch Phys Med Rehabil. 2015; 96:920-927.