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.
What Increases Your Risk. Most people get HIV by having unprotected sex with someone who has HIV. Another common way of getting the virus is by sharing needles with someone who is infected with HIV when injecting drugs. You have an increased risk of becoming infected with HIV through sexual contact if you: 1  Have unprotected sex (do not use condoms). 2  Have multiple sex partners. 3  Are a man who has sex with other men.  Have high-risk partner(s) (partner has multiple sex partners, is a man who has sex with other men, or injects drugs).
You can get infected from sexual contact with someone who is infected with HIV. Sexual contact that can transmit HIV includes: 1  vaginal sex (penis in the vagina). 2  anal sex (penis in the anus of either a man or a woman).ee more tips for using condoms. If you have unprotected sex with someone who is infected, it doesn't mean that you will be infected, too. But there is always a chance, especially if your partner is not on effective HIV medicines. Using a condom reduces your risk. HIV is NOT spread by: 1  hugging or massage. 2  masturbation.