30 June 2026 : Review article
Muscle-Specific Differences in Neuromuscular Block and Quantitative Neuromuscular Monitoring: A Narrative Review
Paweł Radkowski
ABCDEFG 1,2,3, Dawid Kamil Malicki BCDEF 4, Florian Trachte CDEF 5,6, Hubert Oniszczuk CDEF 7*
DOI: 10.12659/MSM.951168
Med Sci Monit 2026; 32:e951168
Introduction
Neuromuscular Conduction
Measurement of Neuromuscular Transmission Depending on Muscle Group: The TOF Method
Adductor Pollicis Muscle
Diaphragm
Muscles of the Arm and Forearm
Orbicularis Oculi Muscle
Corrugator Supercilii Muscle
Laryngeal Muscles
Pharyngeal Muscles
TOF-Cuff Measurements on the Lower Leg
Foot Muscles
Discussion
Future Directions
Conclusions
References
Table 1 Common monitoring sites used for train-of-four (TOF) assessment and the expected observable response with preserved neuromuscular transmission.
| Muscle/region (method) | Stimulated nerve | Observable response with preserved neuromuscular transmission |
|---|---|---|
| Corrugator supercilii muscle | Facial nerve (temporal branch) | Furrowing of the eyebrows |
| Orbicularis oculi muscle | Facial nerve (temporal and zygomatic branches) | Eyelid closure |
| Adductor pollicis muscle | Ulnar nerve (deep branch) | Adduction of the thumb |
| Flexor hallucis brevis muscle | Tibial nerve (medial plantar branch) | Flexion of the great toe at the metatarsophalangeal joint |
| Tibialis anterior muscle | Common fibular nerve | Dorsiflexion of the foot |
| Upper arm/forearm region (TOF-Cuff, compressomyography) | Peripheral nerves within cuff region (ulnar, median, radial, musculocutaneous) | Pressure changes induced by composite muscle contraction |
| TOF – train-of-four; TOF-Cuff – cuff-based compressomyography system. Facial and peripheral muscle responses and innervation patterns are derived from classical neuromuscular monitoring studies and anatomical references. Lower-limb muscle innervation and responses reflect electrophysiological and clinical monitoring data. | ||