Aberrant protective force generation during neural provocation testing and the effect of treatment in patients with neurogenic cervicobrachial pain.

BACKGROUND

Observation of the occurrence of protective muscle activity is advocated in assessment of the peripheral nervous system by means of neural provocation tests. However, no studies have yet demonstrated abnormal force generation in a patient population.

OBJECTIVES

To analyze whether aberrations in shoulder girdle-elevation force during neural tissue provocation testing for the median nerve (NTPT1) can be demonstrated, and whether possible aberrations can be normalized following cervical mobilization.

STUDY DESIGN

A single-blind randomized comparative controlled study.

SETTING

Laboratory setting annex in a manual therapy teaching practice.

PARTICIPANTS

Twenty patients with unilateral or bilateral neurogenic cervicobrachial pain.

METHODS

During the NTPT1, we used a load cell and electrogoniometer to record continuously the shoulder-girdle elevation force in relation to the available range of elbow extension. Following randomization, we analyzed the immediate treatment effects of a cervical contralateral lateral glide mobilization technique (experimental group) and therapeutic ultrasound (control group).

RESULTS

On the involved side, the shoulder-girdle elevation force occurred earlier, and the amount of force at the end of the test was substantially, though not significantly, greater than that on the uninvolved side at the corresponding range of motion. Together with a significant reduction in pain perception after cervical mobilization, a clear tendency toward normalization of the force curve could be observed, namely, a significant decrease in force generation and a delayed onset. The control group demonstrated no differences.

CONCLUSIONS

Aberrations in force generation during neural provocation testing are present in patients with neurogenic pain and can be normalized with appropriate treatment modalities.