USe a weight that gives you a good workout and is doable. Grasp handles on the cable rack machine. Crisscross your forearms and cables so that your right arm works with the left handle and the left arm works with the right handle. Stand with legs shoulder-width apart and knees slightly bent. Bend your arms 90 degrees and straighten them. This works your triceps. Keep your body and upper arms steady. Repeat for five sets of ten repetitions.
Disclaimer: None of the above information can be taken as a substitute for advice from a medical professional such as a physician.
My third book, Pocket Guide to Fitness, is available on www.louizapatsis.com, http://www.authorhouse.com, www.bn.com and http://www.amazon.com. If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories.