Local and Widespread Hypoalgesic Effects of Neurodynamic Mobilization in Healthy Controls

Background & Significance Pain is the primary reason many patients seek care from healthcare professionals who utilize various manual therapy techniques. Gaining further understanding of the hypoalgesic properties of such techniques can enable practitioners to more skillfully integrate them in managing patients presenting with pain. Previous research has revealed that various manual techniques result in both local and widespread hypoalgesic changes in asymptomatic controls and patients in pain. Much of this previous research has investigated thrust manipulation; however, there is a paucity of similar research investigating these effects in neurodynamic mobilization. Specific Aims Aim: To assess for immediate local and widespread hypoalgesic effects of neurodynamic mobilization applied to the upper extremity. Hypotheses: Subjects who receive neurodynamic mobilizations will exhibit greater positive changes in local and widespread Qualitative Sensory Testing (QST) measures compared to those who receive a sham mobilization. Subjects who receive neurodynamic mobilizations will exhibit greater positive changes in elbow ROM and reported sensation intensity with upper limb neurodyndamic testing as compared to those who receive a sham mobilization. Aim: To assess for differences in immediate local and widespread hypoalgesic effects of sliding vs tensioning neurodynamic mobilization techniques applied to the upper extremity Hypotheses: Subjects who receive sliding neurodynamic mobilizations will exhibit greater positive changes in local and widespread QST measures compared to those who receive tensioning neurodynamic mobilization Subjects who receive sliding neurodynamic mobilizations will exhibit greater positive changes in elbow range of motion (ROM) and reported sensation intensity with upper limb neurodynamic testing testing compared to those who receive a tensioning neurodynamic mobilization

neurodynamics, neurodynamic mobilization, quantitative sensory testing, median nerve, pressure pain threshold, thermal pain threshold, thermal pain tolerance

Each subject will be randomized to one of three groups: Neurodynamic Slider Mobilization Neurodynamic Tensioner Mobilization Sham Neurodynamic Mobilization Outcomes will be assessed immediately prior to and immediately following the intervention.

Subjects will be positioned in supine with the examiner supporting his/her arm and facing caudally. The arm will be taken into the ULNT2a position as described in Butler's text - so as to bias the median nerve. Once passive resistance is felt or a feeling of mild tension is reported in the median nerve field, a series of mobilizations will be performed to "slide" the nerve proximally and distally in an alternating manner via providing wrist extension with concurrent shoulder girdle elevation and then providing wrist flexion with concurrent shoulder girdle depression. This will be performed for 2 sets of 10 cycles at a rate of 6 seconds per cycle (3 sec in each position) - not moving further into described tension or passive resistance.

Subjects will be positioned in supine with the examiner supporting his/her arm and facing caudally. The arm will be taken into the ULND2a position as described in Butler's text - so as to bias the median nerve. Once passive resistance is felt or a feeling of mild tension is reported in the median nerve field, a series of mobilizations will be performed to "tension" the nerve in an alternating on/off manner via providing wrist extension with concurrent shoulder girdle depression and then providing wrist flexion with concurrent shoulder girdle elevation. This will be performed for 2 sets of 10 cycles at a rate of 6 seconds per cycle (3 sec in each position) - not moving further into described tension or passive resistance.

Subjects will be positioned in supine with the examiner supporting his/her arm and facing cranially - in a similar position as the UNLD1 test described previously. From here, the therapist will position the patient's arm in 45 deg. of shoulder abduction without scapular depression, 45 deg. of shoulder external rotation, 45 deg. of elbow flexion, and forearm pronation. From this position, a series of sham mobilizations will be performed by passively alternating flexion and extension of the wrist for 2 sets of 10 cycles at a rate of 6 seconds per cycle (3 sec in each position).

PPT will be assessed bilaterally over the thenar eminences, over the dorsal aspect of the 1st carpometacarpal (CMC) joint, and over the tibialis anterior using a pressure algometer with an affixed 1cm2 rubber tip.

TPT will be assessed bilaterally over the thenar eminences, over the dorsal aspect of the 1st carpometacarpal (CMC) joint, and over the tibialis anterior.

TPTol will be assessed bilaterally over the thenar eminences, over the dorsal aspect of the 1st carpometacarpal (CMC) joint, and over the tibialis anterior.

A neurodynamic test of the median nerve will be performed according to the ULNT1 procedure originally described by David Butler. Degrees of elbow extension will then be recorded using a universal goniometer, and each subject will rate each of the following 5 sensory descriptors on a 10 cm Visual Analog Scale (VAS): "Stinging", "Tingling", "Tightness", "Sharpness", and "Numbness". The average of the 5 sensory descriptor ratings will then be averaged to create a single sensory descriptor VAS score - as outlined in Beneciuk et al 2009.

Inclusion Criteria: Age: 18-65 Ability to speak and comprehend English. Exclusion Criteria: Current neck or upper extremity symptoms Disorders that could result in impaired sensation - such as diabetes. Current use of prescription pain medication or other medications that could result in altered pain perception - such as anti-anxiety medications or anti-depressants. History of any chronic painful condition Diagnosis of any major psychiatric disorder Current pregnancy Any painful condition within the past 3 months for which care was sought