Spine Position and Neural Sensitivity
Condition: Sciatic Nerve; Postural Lordosis; Nerve Pain
MeSH terms: Lordosis; Neuralgia
Study type: Interventional

Summary: 
      The purpose of this research study is to see if there is a relationship between the tightness
      of the hamstring muscles (muscles on the back of the thighs), reported sensations related to
      stretch of the nerves of the lower extremity, and different positions of participants' backs.
      We will investigate the qualitative differences as provided verbally by participants
      (sensation felt at maximum knee extension angle) and quantitative differences as provided by
      surface electromyographic (EMG) measurements of hamstring activity and inclinometer measures
      of the knee angle.
    

Detailed description: 
      The Slump Test, introduced by Maitland in 1978, has been a clinical staple for determining
      adverse neural tension or altered neurodynamics and neurosensitivity related to intradiscal
      derangement or stenotic narrowing of the lumbar spine. The slump test is a highly reliable,
      common clinical tool used to assess neural tissue mechanosensitivity in patients with both
      spinal and lower limb pain. However, it is unclear if the slump test can be used to
      differentiate between those with true adverse neural tension compared to those with
      neurosensitivity due to compression of the neuroforaminal interface. The positioning of the
      slump test places maximal tension on the neural tissues both caudally and cranially, either
      reducing knee extension angle (KEA) in the affected side as opposed to the unaffected side,
      provoking radicular symptoms, or both. Hall's research found that there was mechanical
      activity in the hamstring muscles that came on with neural tension testing. This finding can
      be used to objectively assess when a participant is at their peak tolerable limit of neural
      tension in specific trunk positions during the slump test. Observation and clinical
      experience suggest there may be a subset of individuals who have increased neural tension in
      the slump test during spinal extension (shortening of the nerves) as opposed to flexion
      (stretch of the nerves). To date, there has been little research that has objectively
      demonstrated how trunk position affects neural tension during the slump test. Our research
      aims to determine if there is a difference in patient reported symptoms and hamstring
      activity between trunk flexion and extension during the slump test with healthy, younger
      individuals with no recent history of low back pain (LBP) or related symptoms. We expect to
      find a difference in range of motion (ROM), symptoms, and hamstring activity when the slump
      test is done in spinal flexion as opposed to spinal extension. This research will help to
      establish the prevalence of greater sensitivity in the extended vs flexed posture and
      establish a normative set of symptoms as described by healthy individuals.
    

Intervention name(s): Knee extension angle; Straight Leg Raise; Slump Test; Extended slump test
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): Knee Extension Angle (KEA):
This test will be administered with an ankle-foot orthosis (AFO) maintaining the participants ankle in neutral.
The participant will lie supine on the examination table with the contralateral lower extremity (LE) stabilized on the support surface using a mobilization strap.
The hip of the lower being examined will be flexed to 90 degrees.
The participant will then actively straighten their lower leg while maintaining upper leg in same position
Once the participant feels they are at maximal knee extension (patient instructed to straighten leg as far as what is comfortable), the angle will be measured with iPhone Inclinometer.
Participant asked to report any symptoms they are feeling and where (recorded for qualitative analysis); Straight Leg Raise (SLR):
Position the participant in supine on the plinth with knees extended and L LE strapped to the plinth
The participant will keep the AFO donned on the R distal ankle to keep the ankle in neutral position.
A researcher will passively lift the participant's right leg moving at a slow but consistent pace of approximately 15 degrees per second, while keeping it straight until a significant resistance is detected or the participant reports a production of symptoms, whichever occurs first.
Measurement of the SLR angle will be assessed with iPhone inclinometer.
Participant asked to report any symptoms they are feeling and where (recorded for qualitative analysis); Slump Test Procedure:
Participant will be instructed to sit upright with their legs over the edge of table
AFO remains on R leg
Participant will sequentially flex trunk, look down at the floor
Participant will extend R knee until symptoms are felt. Measure of angle with iPhone inclinometer placed at superior aspect of medial malleolus
Participant asked to report any symptoms they are feeling and where (recorded for qualitative analysis); Extended Slump Procedure:
Participant will be instructed to sit upright with their legs over the edge of table
AFO remains on R leg
Participant is asked to arch their lower back into maximal extension in sitting, stabilized to research bench to maintain hyper-lordosis posture.
The participant is asked first flex cervical spine, then to extend their knee until it reaches full ROM or symptoms are felt that limit ROM.
Knee extension ROM is assessed with iPhone inclinometer at superior aspect of medial malleolus.
Participant asked to report any symptoms they are feeling and where (recorded for qualitative analysis)
Other intervention name(s): KEA; SLR
Intervention model: Single Group Assignment
Intervention model description: Quasi-experimental single group laboratory study
Masking: None (Open Label)
Primary purpose: Basic Science