1 Isotonic -a muscle fiber contraction in which force production is unchanged when the muscle contracts causing movement of an external load.  Isokinetic -a muscle fiber contraction in which force production of the contraction is sufficient to overcome the external load.
HIV/AIDS. HIV Risk Behaviors. The risk of getting HIV varies widely depending on the type of exposure or behavior (such as sharing needles or having sex without a condom). Some exposures to HIV carry a much higher risk of transmission than other exposures.
You can become infected with HIV in several ways, including: 1  By having sex. 2  From blood transfusions. 3  By sharing needles. 4  During pregnancy or delivery or through breast-feeding. 5  Symptoms. 6  Risk factors.