Taken from original article by Kelly Maclean available from shouyuliang.com through this link
Kelly Maclean has practiced martial arts for over 10 years and is a both a national and international Taiji champion. --------------------------------------------------------------------------
For Wushu, both shoulder strength and flexibility are required. Increasing these attributes can help give you more control in your forms and weapons.
Strength
This is a series of three exercises I learned from Master Nick Gracenin, a well-known teacher, athlete, and promoter of Chinese martial arts in PennShou-Yu Liangvania. Try fifty repetitions for each exercise, without resting in between. As far as the speed is concerned, approximately one repetition per second is about right. Exercise 1 
Start by standing with the feet at a comfortable distance apart. Hold the arms 180 degrees out to the sides, at shoulder level, with the elbows straight, and the fingers straight, together, and pointing upward. Keep the chest open.
Rotate the shoulders 90 degrees forward, so that the fingers point forward. Keep the shoulders down, elbows straight, hands tight, and chest open.
Return to the start position. Be sure not to over-rotate; fingers should not point backward. Try 50 repetitions, and without resting, go on to the second exercise.
Exercise 2
Remaining in your stance, begin with your fingers pointing forward. Keep the arms 180 degrees out to the sides, at shoulder level, with the elbows straight and the chest open. With the fingers pointing forward, pull your arms back as far as possible, keeping the elbows straight, shoulders down, and hands tight. Do not arch your back.
Return your arms to 180 degrees apart. Repeat fifty times, and without resting, go on to the third part.
Exercise 3
Remain in your stance and begin again with your fingers pointing forward. Bend the elbows slightly and pull them back, so that the chest stays open. Lift the elbows as high as you can, without lifting the shoulders themselves. Return the elbows to level with the shoulders. Resist dropping the elbows below the shoulders. Try to do fifty. After this final exercise, you will probably be ready for a stretch!
Flexibility
Here are some basic stretches to help keep the shoulders limber. All you need is a wall. Try holding each stretch for 30 seconds to a minute.
Stretch 1
Start with your palms against the wall at approximately shoulder height and less than shoulder width apart. Lean forward, keeping the arms and legs straight, until your arms are behind your ears. You should feel the stretch in the shoulders. See if you can touch your head to the wall. Avoid arching the back.
Stretch 2
Next, turn away from the wall, and get your palms against the wall, as close together as possible, with the fingers pointing upward, thumbs on the outside. Bend your knees, and lower your body. Keep the elbows straight, and hands as high and as close together as possible.
Stretch 3
Standing with one palm against the wall, the arm straight and up at shoulder height. Turn your body away from your arm. Of course, stretch both sides.
