Related Experiment Videos
Clarification of the pronator reflex
1Sports Medicine Center, Mayo Clinic Rochester, Minnesota 55905.
American Journal of Physical Medicine & Rehabilitation
|September 1, 1994
Summary
The pronator reflex, used for evaluating cervical roots, specifically involves the pronator teres muscle, not the pronator quadratus. This finding clarifies its diagnostic utility for C6 and C7 nerve root lesions.
Area of Science:
- Neurology
- Neurophysiology
- Clinical Electrophysiology
Background:
- The pronator reflex is utilized for assessing the 6th and 7th cervical nerve roots.
- Previous literature lacks clarity on the specific muscles involved in the pronator reflex.
Purpose of the Study:
- To identify the specific pronator muscle(s) responsible for the pronator reflex.
- To confirm the reflex's utility in evaluating C6 and C7 root lesions.
Main Methods:
- Surface electromyography (EMG) was used to record muscle activity.
- Recordings were taken over the pronator quadratus and pronator teres muscles in 10 healthy subjects.
- A Teca reflex hammer induced muscle stretch to trigger EMG.
Main Results:
- A reproducible electromyogram response was consistently observed over the pronator teres (mean latency 9.7 ± 1.8 ms).
- No electromyogram response was detected over the pronator quadratus in any subject.
- The pronator reflex was identified as a muscle stretch reflex of the pronator teres.
Conclusions:
- The pronator reflex is mediated by the pronator teres muscle.
- The pronator quadratus is not involved in this reflex.
- This clarification enhances the diagnostic value of the pronator reflex for C6 and C7 cervical root lesions.