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.
Due to loneliness and the availability of money, these men may have unprotected sex with other women or men and become HIV-infected. These HIV-positive men may, in turn, infect their wives and other sexual partners. Some beliefs can result in increased risk of HIV infection.