Abstract
M. Tech. Chiro.
The purpose of this study was to determine the effect that C5 and C6 spinal
manipulative therapy had on alpha motorneuron excitability of the
musculocutaneous nerve in the biceps brachii muscle. Readings were recorded
using Electromyography (EMG).
Eighty asymptomatic subjects participated in this study. The subjects selected had
to be between 18 and 35 years of age, having experienced no cervical pain,
discomfort or pathology. The subjects had to present with a C5 or C6 joint motion
restriction based on motion and static palpation. Patients were selected based on
their response to advertisements posted throughout the Technikon Witwatersrand.
Forty of the subjects were placed in the test group and received C5 or C6 joint
manipulation once off. The other forty subjects were placed in the control group.
EMG readings were taken before, at the time of, and after the spinal manipulative
therapy, to ascertain whether the adjustment influenced the strength of the biceps
brachii contraction and the reflexive action of the muscle. Pressure algometry was
used on the biceps brachii as a subjective test on each patient. A repeated measure
student’s t-test was performed, including a Normality and Equal Variance Test for
control and trial groups.
This study showed that spinal manipulative therapy momentarily increases alpha
motorneuron excitability in the biceps brachii muscle in 71.4% of the patients
with C5-C6 joint motion restrictions.
Dr. C. Yelverton
Dr. C. J. Hay