[Mike O]

Couldn't this slight increase in right tricept muscle force also be atributed to extensor action, it is impossible for the right tricept to ever be completly inert as some force must be exterted to creast extensor action to take the slack out of the assembly.

Within the context Jeff's post- I was thinking any comment to right tricep pushing was used in the context of an acceleration force. Certainly, in the context of your post - regarding extensor action there would be right tricep muscle force attributed to extensor action- separate from any pushing acceleration force.