Motor Points for the Neuromuscular Blockade of the Subscapularis Muscle
Presented in part to the Seddon Society, June 16, 2006, Stanmore, UK, and the British Association of Clinical Anatomists, July 18, 2006, Keele, Staffordshire, UK.
Abstract
Harrison TP, Sadnicka A, Eastwood DM. Motor points for the neuromuscular blockade of the subscapularis muscle.
Objective
To locate the motor points of the subscapularis muscle in relation to palpable anatomic landmarks and hence suggest a technique for botulinum toxin injection into subscapularis applicable to patients of all ages.
Design
Anatomic dissection of the innervation of 20 subscapular muscles.
Setting
University dissecting room.
Cadavers
Ten formalin-preserved cadavers.
Interventions
Not applicable.
Main Outcome Measure
The location of motor points in relation to anatomic landmarks.
Results
The median number of motor points for the subscapularis was 5 (range, 3−6). All motor point measurements were related to surface points and converted into proportional values along reference lines. Motor points from the 20 dissections showed clustering in a band. A line of best fit was calculated (y=1.48x–0.743).
Conclusions
We describe an injection technique that would deliver botulinum toxin close to the motor points of the subscapularis, a surrogate marker of the motor endplate zones. By using proportional distances, this technique is applicable to an adult and pediatric population. This should lead to an increased efficacy and decreased side-effect profile in clinical practice, although clinical trials will need to confirm this.
Correspondence to Deborah M. Eastwood, MB, FRCS, Dept of Orthopaedics, Great Ormond Street Hospital for Children, London, WC1N 3JH, UK
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.
ABSTRACT