Differences between motor point and innervation zone locations in the biceps brachii. An exploratory consideration for the treatment of spasticity with botulinum toxin

Concordance of the location of the innervation zone of the tibialis anterior muscle using voluntary and imposed contractions by electrostimulation

“…When the arrays are placed parallel to the muscle fibers, it is possible to observe the propagation of motor unit action potentials (MUAPs) along the muscle fibers. The point where these are originated or they change their propagation direction has been defined as the location of the IZ (Merletti et al, 2003;Beck et al, 2012;Guzman-Venegas et al, 2014).…”

“…In this procedure, levels of muscle contractions between 10% and 75% of the maximum voluntary contraction (MVC) have been used (Piitulainen et al, 2009;Guzman-Venegas et al, 2014). Patients with spasticity have impaired in voluntary muscle activation associated with lower amplitude of electromyographic recordings of the affected muscles (Li et al, 2014).…”

Three-Dimensional Innervation Zone Imaging from Multi-Channel Surface EMG Recordings

“…14 Unfortunately, the location of IZs varies between muscles and individuals, and currently there is no consensus about techniques which can be used to define IZs accurately. 15 To bridge this gap, the 3DIZI approach was developed to accurately image the distribution of IZs in the 3D space of the target muscles from high-density surface EMG recordings. The surface location of the IZ of each decomposed MU identified from the bipolar map of their MUAP trains was utilized to constrain the source space of the muscle activity imaging solution in the 3DIZI approach to greatly improve its localization accuracy.…”

“…15 Clinically, the motor point (MP) is used as the injection site of BTX since it is broadly homologous to the IZ. However, a significant difference between the MP and IZ locations has been reported.…”

“…However, a significant difference between the MP and IZ locations has been reported. 15 Bipolar high-density surface Electromyography (EMG) mapping has also been used to localize IZs over the skin surface to improve the BTX injection outcome, 14 but the application of this surface localization method is limited by the lack of the depth information of the IZs, particularly due to peripheral adaptive changes including atrophy and fat tissue deposit. 16 3D IZ location is therefore needed in order to improve clinical outcomes with minimal treatment dosages and thus minimize side effects.…”