Its Monday morning, 8 o’clock gym class. Students are trickling in talking about all the fun they had over the weekend. Coach enters and all the students fall into place.
“Okay guys lets warm up first with our feet shoulder width apart,” he shouts, ” Lets get those hamstring. I want you to reach down and stretch those muscles good. Now make sure you bounce up and down so you can really stretch those muscles out. STRETCH!!!!”
This old practice is called Ballistic stretching. It is wrong.
Ballistic (bouncing) stretching consists of rapid jerky movements in which a body part is put into motion (smith et al., 1993; Hedrick; 2000) . Momentum carries the body part through a full range of motion (ROM) until the muscles area stretched to maximal physiological limits (Bandy et al. , 1997).
Ballistic stretching is not recommended because ballistic movements put the individual at greater risk for incurring injury and delayed onset muscle soreness. Delayed onset muscle soreness, which we will discuss in detail at a later date, is pain that may occur during the activity, immediately after the activity, or may be delayed for 24 to 48 hr after the termination of activity. Ballistic movements increase flexibility as much as static movements. Ballistic movements are more effective because these movements mimic parts of motor patterns such as start of the vertical jump (Smith et al. 1993) . Contrary to Smith et al. (1993), Hedrick (2000) found that ballistic stretching had negative effects. These negative effects occurred because ballistic movements are performed at high speeds and the rate of the stretch and force applied to induce the stretch and force applied to induce the stretch is very difficult to control (Hedrick, 2000) .
Hedrick compared ballistic and static stretching techniques and found four disadvantages of ballistic stretching:
(1) there is an increased danger of exceeding the extensibility limits of the tissue involved;
(2) energy requirements are higher;
(3) muscle soreness may occur, which static stretching will not cause; and
(4) activation of the stretch reflex (2000) .
In other words, when you stretch – DO NOT BOUNCE!