I am sure you have seen someone trying to squat or clean a heavy weight and perform a double bounce at the bottom of the squat in order to get out of the hole. Why do they do this? How does it help? And is it safe?
The double bounce technique is actually a strategic skilled used by more experienced lifters to assist them in getting out of the hole (out of the bottom of a squat) of a heavy lift. It is not something used by mistake but actually has scientific support behind it.
There have been studies done that support that the double bounce, when used properly, assists an athlete in lifting heavier weight. For some sports that judge the athlete on max weight lifted, this is important and a great skill to master. It is important to remember; however, even these athletes still train lifts at controlled tempos and without the double bounce for strengthening effects. They tend to use this double bounce as the weight gets heavier or if going for a 1 rep max.
The Science Behind It
The double bounce technique uses a phenomenon known as the "stretch reflex". The stretch reflex is really a protective response from the body to protect muscles, tendons, and ligaments from damage during certain scenarios. The stretch reflex is activated when a stretch is applied to a muscle/tendon. From that stretch, signals are sent to the spinal cord and then back to the muscle resulting in a contraction of that muscle. The contraction is meant to control the stretch on the muscle so that the muscle is not stretched to a length it can't handle. This response happens extremely fast as it bypasses the brain and travels directly to the spinal cord and back to the muscle...as in milliseconds fast.
During the double bounce, the bounce results in a rapid stretch of primarily the quad muscle and tendon. When this occurs, messages are rapidly sent to the spinal cord and then back to the muscle resulting in a contraction of the muscle allowing for the necessary torque production needed to complete the lift.
Is It Safe?
The double bounce technique is just that.....A TECHNIQUE. It takes practice and proper performance to achieve the benefits. It still requires a level of control and precision to be done properly. It also requires that you don't lose tension in the midline during the bounce in order to maintain optimal body position for completion of the lift. But when done properly it is very useful and safe!
Written by: Marissa Oxenford, PT, DPT, CMFA-cert, CF-L1 Trainer, CPT