Optimal injection points for the neuromuscular blockade of forearm flexor muscles: a cadaveric study

Botulinum toxin acts at neuromuscular junctions close to muscle motor points and is used to help manage spastic upper-limb deformities. To develop a system allowing clinicians to identify optimal injection sites by an easily reproducible technique, forearm flexor muscles were dissected in 20 formalin-preserved human limbs. Motor points for flexor carpi ulnaris, flexor carpi radialis, flexor digitorum superficialis and pronator teres were (1) identified, (2) related to a reference grid based on lines (proximal, distal, lateral, medial and diagonals) drawn between forearm anatomical landmarks, and (3) defined in terms of their percentage distances along the established grid lines.