Study design: Two-group repeated measures.
Objectives: To evaluate the changes in the flexor carpi radialis H reflex after reading and neck retraction exercises and to correlate reflex changes with the intensity of radicular pain.
Background: Repeated neck retraction movements have been routinely prescribed for patients with neck pain.
Methods and measures: Ten nonimpaired subjects (mean age, 27 +/- 4 years) and 13 patients (mean age, 35 +/- 9 years) with C7 radiculopathy volunteered for the study. The flexor carpi radialis H reflex was elicited by electrical stimulation of the median nerve at the cubital fossa before and after 20 minutes of reading and after 20 repetitive neck retractions. Subjective intensity of the radicular pain was reported before and after each condition using an analog scale.
Results: For patients with radiculopathy, a repeated-measures analysis of variance showed a significant decrease in the H reflex amplitude (from 0.81 +/- 0.4 to 0.69 +/- 0.39 mV), an increase in radicular symptoms after reading (from 4.2 +/- 1.3 to 5.6 +/- 1.4 on the visual analog scale), an increase in the H reflex amplitude (from 0.69 +/- 0.39 to 1.01 +/- 0.49 mV), and a decrease in pain intensity (from 5.6 +/- 1.4 to 1.5 +/- 1.3) after repeated neck retractions. There was an association between cervical root compression (smaller H reflexes) and increased pain during reading and between cervical root decompression (larger H reflex) and reduced pain (r = -0.86 to -0.60). Exacerbation of symptoms was found with a reading posture. There were no significant changes in the H reflex amplitude in the nonimpaired group. No changes were found in reflex latency for either groups.
Conclusions: Neck retractions appeared to alter H reflex amplitude. These exercises might promote cervical root decompression and reduce radicular pain in patients with C7 radiculopathy. The opposite effect (an exacerbation of symptoms) was found with the reading posture.