Pacheco L, Balius R, Aliste L, Pujol M, and Pedret C. J Strength Cond Res. 2011 July; 25(11) 2991-2998.
Proper stretching prior to an activity is critical in avoiding injury. There are many different stretching exercises which can be performed and choosing the correct stretching exercise can actually enhance how the muscle and tendon will react to the demands placed on it during the activity. In order to better understand the effects of different stretching exercises with respect to jump performance, Pacheco and colleagues performed a double-blind, crossover study. The purpose of this study was “to evaluate the differences between different types of static stretching, which differ in terms of both their extension times and muscle activation or relaxation during the execution.” A total of 38 patients took part in the study in which 5 different stretching techniques were assigned. Patients performed 1 of the following lower extremity stretching interventions; 1) static passive stretching (stretch and hold for 30 seconds), 2) proprioceptive neuromuscular facilitation (PNF) stretching (contracting for 4 seconds and passively stretched immediately after), 3) static active stretching in passive tension (contracting the antagonist muscle), 4) static active stretching in active tension (simultaneous contracting agonist muscle and stretching), or 5) no stretching. The effectiveness was evaluated by having the patients perform a jump test both before and after intervention. The jump test consisted of a squat jump, countermovement jump, and a drop jump. Each jump was performed 3 times with a 20 second rest between each jump and a 1 minute rest between each jump type. The best height for each of the three jumps was used. They found the static passive stretching, PNF stretching, and static active stretching in active tension showed significant increases in performance post intervention compared to the pre-test. The greatest significant difference was found in static active stretching in active tension.
There have been several recent SMR posts on the significance of static stretching (see below). You can view them below in the related posts section. This study was designed to examine the effect of performance on several different types of static stretching. Overall this was an interesting study but some aspects were difficult to follow due to a lack details about the stretches being performed. However, the greatest statistical differences were detected in stretches which not only lengthened the muscle but also called on the muscle to contract in an elongated state replicating the demands of activates. This contracting action begs the question. “Are these stretches truly static stretches?” While all stretches were preformed differently, in essence all stretches in this study require some movement or contraction to increase flexibility and explosiveness as demanded by the activity. These PNF stretches may be more effective at increasing flexibility but also increasing the action potential of the muscles which can improve functional performance. As reported in other posts, training the muscle towards its specific demands seems to yield the greatest effectives during activity. Many of you have offered up thoughts concerning the effects of injury prevention, but what about other gains? Have you seen or heard of your athletes making gains in elements of their activity such as jumping ability or explosiveness?
Written by: Kyle Harris
Reviewed by: Stephen Thomas
Pacheco L, Balius R, Aliste L, Pujol M, & Pedret C (2011). The acute effects of different stretching exercises on jump performance. Journal of Strength and Conditioning Research, 25 (11), 2991-8 PMID: 21993032