Dear Sir, as a doctor and with my experience of treating patients with Sciatica nerve pain --- where Sciatica is  not a medical diagnosis in and of itself—BUT---it is a symptom of an underlying medical condition, such as a lumbar herniated disc, degenerative disc disease, or spinal stenosis. if and have to manual therapy is done as a choice of treatment along with medication and injections and lumbar belt support and physiotherapy then the radicular pain( radiating pain) is measured a NPS (Numerical Pain Scale) from 1 to 10  as 1 to be no pain and 10 to be intolerable pain. usually during the manual therapy the pain scale by NPS is of 6-8 before and after manual therapy. Thanks.

Try to measure flexion range of motion of  hip joint before and after therapy.

I take that the radiculopathy is the result of either disc disease (bulging or herniated) or degeneration of the facet joints. Other pathologies are excluded after the pre-intervention screening. The objective measurement has to be performed using a device before and after the given treatment. The questionnaire scales are subjective and not objective (even those that are validated from institutions). In my experience there is no device to measure radicular pain and give a quantitative reading. The pain score table for disability can be used, but it is subjective. It is validated by the Societies and Social Security Agencies and used to assess disability of back pain sufferers in general.

One classic test to assess and quatify the effect of manual therapy oncases with schiatica (symtom not syndrome as mentioned above !) is the straight leg raise test (Lasegue's sign). If this sign is positive at 30 degrees raise before therapy and positive at 60 degerees after it, then you may register quatitative imrovement. It is not entirely objective, but to some useful extent.

Laseque or Straight Leg Raise is a test that may give you some answer and I agree with Panayot but what if the initial is measuring 30 and the latter 35 -40 degrees. This is a possibikity that the objectivity may be questioned and this is what Panayot is saying that it "is not entirely objective".

It is better to go through the pain score table. Because differences in first day and last day complaint may observed easily. We are diing Cupping and massage regular for five 10 to 15 days and observed by the same pain score table for the same condition. 

I do insist on straight leg raise test applicability because this test provokes and reproduces the pain intensity.  It is well known that usually   pain relieves in hip and knee position, so it depends on the position. And second, it is strogly subjective. 

The difference in degree of the SLR in combination with the slump

There  can by the SLR also with more inversion of the foot give an higher reaction . Two reaction are important , first the resistance and the neurological symptom

succes

In addition to all that was mentioned, a chart with clear marking of location of pain can demonstrate if the pain changes to be more proximal or distal and is therefor useful. 

Documentation of the movements that reproduce the pain and in what range can also be helpful (as with SLR and Slump). Por example in side flexion, how far down does the patient reach untill the pain is produced.

Agree with the posts written above, that straight leg raise test can give you valuable information. It will also show you changes in their motor abilities influenced by your therapy, which should be important for both you and your patients. By my opinion it is fine that the test is not entirely objective, since the patients subjective feeling of the pain level is highly influencing their quality of life. 

Regards,

Vladimir

It seems no standardized outcome measure is available for objective assessment of radicular symptoms but instruments like Visual Analogue Scale and Modified Oswestry Disablity Index are not out of place since radicular symptoms include pain and disability.

Measurement with SLR and slump can give an differences in degree of hip ankle and that can be an measurement that indicates that som relieve must have taken place.. Shalock / butler and Coppetiers ( NOI) used this also and of course an VAS scale 

I agree with Jan Van de Rakt. SLR and Slump/modified Slump can give you the differences in joint magnitude. NOI and Neurodynamics Solutions use this. You can also have a look on this article. You will find the usage and validation of the maneuvers.

Miller, K. J. (2007). Physical assessment of lower extremity radiculopathy and sciatica. Journal of Chiropractic Medicine, 6(2), 75–82. http://doi.org/10.1016/j.jcme.2007.04.001

You could consider utilizing patient-reported outcome assessments such as the Sciatica Bothersomeness Index or Sciatica Frequency Index:

Article The bothersomeness of sciatica: Patients' self-report of par...