Comparative Effects of Tensioning and Sliding Neural Mobilization on Nerve Root Function :Randomized Controlled Trial

Initial participant positioning for gliding will be : lying in supine, shoulder at approximately 90 of abduction, wrist in neutral, elbow at 90 flexion and head/neck neutral. From this starting position, participants actively and simultaneously will perform extension of the elbow (to 45) and ipsilateral neck flexion (to approximately 45) and then returned to 90 of elbow flexion and 45 of contralateral neck flexion while maintaining the shoulder at 90 abduction. According to Silva et al., (2014) this combination of movements was the one that promoted the greatest excursion of the median nerve (10.2 mm) . For gliding, four series of 10 movements at a rhythm of approximately 6 s per cycle and 1-min rest between series was performed.

Tensioning will be performed with the subject lying supine. The investigator will perform the upper limb neurodynamic test as reported by Butler (2000): shoulder depression; 110 of shoulder abduction; external shoulder rotation; wrist and fingers extension; forearm supination and then elbow extension. The final test position will be defined as either i) end of joint amplitude or ii) the joint amplitude that provokes pain, paresthesia or numbness. In this case, a decrease of 5 to 10 of range of motion (elbow extension) will be allowed for symptoms to disappear and from this end position the investigator will perform repetitive movements of approximately 10 of elbow flexion/extension while maintaining the test end position for all the other joints. For tensioning, four series of 10 movements at a rhythm of approximately 6 s per cycle and 1-min rest between series will be performed. After each cycle of 10 repetitions, the position will be held for 10 seconds.

Participants in the sham group will receive a treatment consisting of maneuvers that mimic the neural mobilization treatment but not to stress the neural tissues in the upper extremity. The sham mobilization consists of passively positioning the participants in the following consecutive positions: (1) a neutral cervical spine (0° of lateral flexion), (2) 45°of shoulder abduction without scapula depression, and (3) 45° of shoulder external rotation combined with 45° of elbow flexion with forearm pronation. This will be immediately followed by 10 cycles of passive wrist flexion/extension at a rate of approximately 6 seconds per cycle (3 seconds into extension and 3 seconds into flexion) . Upon moving from wrist flexion to extension, an initial sense of resistance will be used as a sign to alternate directions. Following the 10th cycle, a static hold will be maintained while in wrist flexion for 10 seconds.