Stretching is usually performed before exercise in an attempt to enhance performance and reduce the risk of injury. Most stretching techniques (static, ballistic, and proprioceptive neuromuscular facilitation) are effective in increasing static flexibility as measured by joint range of motion, but the results for dynamic flexibility as measured by active and passive stiffness, are inconclusive. The mechanisms of various stretching techniques in terms of biomechanics and neurology, the effectiveness of the combination of stretching with other therapies such as heat and cold, and the effectiveness of stretching for performance and injury prevention are reviewed. The possible mechanisms responsible for the detrimental effects of stretching on performance and the minimal effects on injury prevention are considered, with the emphasis on muscle dynamic flexibility. Further research is recommended to explore the mechanisms and effects of alternative stretching techniques on dynamic flexibility, muscle soreness, sport performance, and rate of injury.