Spine Position and Neural Sensitivity

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.

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.

Eligibility Criteria:
Inclusion Criteria:

* healthy individuals between the ages of 18 and 65 without low back pain.

Exclusion Criteria:

* Known previous diagnoses of sciatica or disc herniation
* Diagnosis of scoliosis
* History of pain in the low back or back of the leg
* History of back surgeries
* Any recent hamstring injuries
* Any recent fractures
* History of osteoporosis
* Have feeling of pins and needles down the leg
* Have a known nervous system disorder
* Have a known systemic inflammatory condition
* Have Rheumatoid Arthritis
* Known history of cardiovascular issues
* Have a known connective tissue disorder
* Bowel/bladder issues
* Are or may be pregnant
* Type 1 or type 2 diabetes mellitus
* Active/history of cancer
* Allergy to adhesives
* Are actively involved in a lawsuit regarding personal bodily injury or receiving workman's compensation
* Currently taking/have recently taken antibiotics known as fluoroquinolones (ie. Cipro, Levaquin, Noroxin)