That stretchy stuff that Alden is talking about is available from many companies, such as this one
http://www.thera-band.com/
The problem with most strengthening programs is that they train in straight planes of movement, and we do not canoe (or move) that way. For the best results use exercises that most closely resemble your canoe stroke (or better yet, just keep paddling).
For example, here is a helpful site- go to
http://www.selu.edu/Academics/Faculty/r ... rrehab.pdf
Ignore all the stuff until the diagrams on the bottom of p. 4. Try this-
Get a piece of ‘stretchy stuff’, tie a knot in 1 end, and put the knot over a door and shut the door. Then hold the other end of the band in your hand while you move from D2 flexion to D2 extension then back to D2 flexion. This will strengthen the coordinated movements of shoulder extension, internal rotation and adduction along with elbow extension. It also mimics the movements of the “up” (T-grip) arm in paddling. COOL!
A nice thing about including rotation in shoulder exercises is that it trains the shoulder to clear the greater tubercle of the humerus from the acromium process. When this does not occur accurately we pinch on the supraspinatus tendon and get tendinitis of a rotator cuff muscle (a common problem on the T-grip arm).
After that exercise take the stretchy stuff and stand on the knot with 1 foot. With the opposite arm move from D2 extension to D2 flexion and back to D2 extension.
These are good techniques, but give them plenty of time to achieve strengthening (“Wolff’s Law” in the handout with the exercises). Plan on changes in strength and coordination taking weeks/months to achieve.
Good luck,
Jim