Brachialis Transposition

[bijou2000]

I'm a first year vet student and was reading about treatments for radial nerve damage on a UPenn vet school website
http://cal.vet.upenn.edu/saortho/chapter_66/66mast.htm

One of the treatments discussed involves trasposition of the brachialis muscle to serve as an extensor of the elbow, since the original extensor muscles of the elbow will not be innervated by the damaged radial nerve. My question is: if the musculocutaneous nerve continues to innervate the biceps brachii (flexor of the elbow) and also innervates the brachialis (now an extensor of the elbow) doesn't innervation of the biceps brachii and brachialis negate each others motions? How can you have one nerve innervate agonist/antagonist muscles? Thanks,
Kim

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[macula_densa]

The reason it is so important to have an elbow extensor is because the primary weight bearing muscle in the forelimb is the triceps. However, weight bearing is complex and involves muscles of both extension and flexion. If the dog was trying to do biceps curls, he would likely have a problems following a brachialis transposition since he wouldn't be able to isolate elbow flexors. However, for weight bearing, it is probably acceptable to have both extensors and flexors innervated by the same nerve. Otherwise, without radial nerve innervation and subsequent extensors, weight bearing is not possible.

I'm a first year vet student and was reading about treatments for radial nerve damage on a UPenn vet school website
http://cal.vet.upenn.edu/saortho/chapter_66/66mast.htm

One of the treatments discussed involves trasposition of the brachialis muscle to serve as an extensor of the elbow, since the original extensor muscles of the elbow will not be innervated by the damaged radial nerve. My question is: if the musculocutaneous nerve continues to innervate the biceps brachii (flexor of the elbow) and also innervates the brachialis (now an extensor of the elbow) doesn't innervation of the biceps brachii and brachialis negate each others motions? How can you have one nerve innervate agonist/antagonist muscles? Thanks,
Kim