Related Experiment Video
Updated: May 18, 2026
Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation
Published on: September 13, 2015
T-reflex studies in human upper limb muscles during voluntary contraction: normative data and diagnostic value for
Tomoko Tetsunaga1, Toshikazu Tani, Masahiko Ikeuchi
1Department of Orthopaedic Surgery, Kochi Medical School, Kohasu Oko-cho, Nankoku, Japan. kwdtmk1201@yahoo.co.jp
Objective:
To evaluate the diagnostic utility of the T reflexes elicited from the upper limb muscles during standardized volitional contraction monitored by a real-time integrating electromyographic analyzer.
Design:
Prospective descriptive study.
Setting:
Department of orthopedic surgery at a university hospital.
Participants:
Healthy subjects (n=80) evenly distributed across decades of age from 21 to 79 years, and 12 consecutive patients with a single cervical root lesion based on clinical and magnetic resonance imaging studies and diagnostic block.
Interventions:
Not applicable.
Main Outcome Measures:
Using a special hammer, which externally triggers the sweep on skin contact, we evoked T reflexes in the biceps (C5), brachioradialis (C6), triceps (C7), and the first dorsal interosseous muscles (C8).
Results:
Simultaneous regression analyses yielded clinically useful upper limits of normative values for latencies, side-to-side differences, and amplitude ratios adjusted to age and arm span. Comparison of the T reflexes between the 2 sides localized the solitary root lesions with a high sensitivity (92%), specificity (81%), and accuracy (83%). T-reflex studies proved helpful to localize the lesion even in patients who solely complained of upper limb pain.
Conclusions:
The T reflexes with a standardized facilitation of the upper limb muscles provide a clinically useful, noninvasive measure to localize the C5 to C8 radiculopathies. This study contributes in reassessing the currently underused T reflex as an electrodiagnostic technique.
