Skeletal muscle contractions can be concentric or positive, eccentric or negative or isometric. Many skeletal muscle contraction involve muscle fibers shortening, as described in the previous card. Eccentric muscle contractions involve the lengthening of muscle fibers. Individual muscle fibers contract, but the resistance is greater than the force generated, and the muscle lengthens.
During isometric muscle contraction, individual fibers contract, but there is no muscle fiber length change. Usually the pressure exerted by the muscle is equal to the pressure exerted by an outside mass such as another person or a wall.
For the past several blog posts, I have not created exercise programs. Look to past posts or search by muscle group, and you will find them!
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.