Trans‐spinal magnetic stimulation induces co‐activation of the diaphragm and biceps in healthy subjects

• Published in: Physiological reports Vol. 12; no. 3; pp. e15941 - n/a
• Main Authors: Ren, Ming‐Yue, Liou, Li‐Min, Vinit, Stéphane, Lee, Kun‐Ze
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01.02.2024; Wiley; John Wiley and Sons Inc
• Subjects: Animals; biceps; Biochemistry, Molecular Biology; Body mass index; Diaphragm; Diaphragm (Anatomy); Diaphragm - physiology; Electric Stimulation; Electrodes; Electromyography; Feasibility studies; Female; figure‐of‐eight coil; Forelimb; Healthy Volunteers; Humans; Latency; Life Sciences; Limbs; Magnetic fields; Magnetic Phenomena; Male; Males; Muscles; Original; Physiology; Spinal cord; Thoracic Vertebrae; Thorax; Transcranial magnetic stimulation; trans‐spinal magnetic stimulation; Vertebrae; diaphragm; figure-of-eight coil; trans-spinal magnetic stimulation; biceps
• ISSN: 2051-817X; 2051-817X
• DOI: 10.14814/phy2.15941

The present study was designed to examine the effect of trans‐spinal magnetic stimulation on bilateral respiratory and forelimb muscles in healthy subjects. Two wings of a figure‐of‐eight magnetic coil were placed on the dorsal vertebrae, from the fifth cervical to the second thoracic dorsal vertebra with a center at the seventh cervical vertebra. The surface electromyograms of bilateral diaphragm and biceps were recorded in response to trans‐spinal magnetic stimulation with 20%–100% maximum output of the stimulatory device in male (n = 12) and female participants (n = 8). Trans‐spinal magnetic stimulation can induce a co‐activation of bilateral diaphragm and biceps when the stimulation intensity is above 60%. The onset latency was comparable between the left and right sides of the muscles, suggesting bilateral muscles could be simultaneously activated by trans‐spinal magnetic stimulation. In addition, the intensity–response curve of the biceps was shifted upward compared with that of the diaphragm in males, indicating that the responsiveness of the biceps was greater than that of the diaphragm. This study demonstrated the feasibility of utilizing trans‐spinal magnetic stimulation to co‐activate the bilateral diaphragm and biceps. We proposed that this stimulatory configuration can be an efficient approach to activate both respiratory and forelimb muscles. Trans‐spinal magnetic stimulation is a feasible method to activate the diaphragm and biceps and produce the motor evoked potential recorded by surface electromyogram. Coactivation of bilateral diaphragm and biceps could be induced by trans‐spinal magnetic stimulation simultaneously when the intensity is over 60% maximal stimulus output.