As discussed in previous blogs, mobility has never been more important in the modern game. Below is an article by Matt Kuzdub (http://www.mattspoint.com/) which was part of his 3 blog series on mobility and flexibility for tennis.
Let us know your thoughts….
BOTH DYNAMIC AND STATIC STRETCHING PLAY A BIG ROLE DURING THE TENNIS WARM-UP
This is the third part of this 3-part series on mobility & flexibility training for tennis. The first post was an introductory post that defined what mobility truly is (read that here) and highlighted some of the problem areas for tennis players – with a special emphasis on the hip and shoulder. The second part went into more specifics regarding the science of stretching and it’s role in the overall development of mobility. That post also included detailed info on how to improve both range of motion (ROM) and strength within those ranges and outlined a shoulder internal rotation stretch example. You can read that article here.
In this post, we’ll primarily be looking at the differences between dynamic and static stretching. More specifically, we’ll outline what role dynamic stretching (DS) and static stretching (SS) play in the warm-up of the tennis player and how to effectively implement each type of stretching into your pre-match/practice routine. Let’s go!
DYNAMIC VS STATIC STRETCHING – DEFINITIONS AND PERFORMANCE IMPLICATIONS
We’ve already outlined static stretching (SS) in the previous post (click on this link for full article internal link) and looked at it’s effect on injury prevention (if you haven’t read that post, spoiler alert, traditional static stretching WON’T prevent injury). Just to refresh your memory, SS implies holding a particular position for a period of time with no movement of limbs, joints, muscles etc. An example being bending your torso to touch your toes and holding that position.
Dynamic stretching (DS) on the other hand, involves moving a joint or muscle group through a particular range of motion and in a particular direction. Examples of this can come in the form of forward lunges, leg swings or hip rotations. Although still a relatively new phenomenon (with regards to the literature), most research has supported the use of DS as part of an effective warm-up because of it’s good correlation with various performance measures (Behm 2011).
DYNAMIC STRETCHING, STATIC STRETCHING AND PERFORMANCE
Although some research has pointed to the benefits of DS for performance enhancement, a recent systematic review by Behm et al (2016) revealed that neither DS nor SS had any significant effects on performance. Meaning, both types of stretching didn’t seem to either hinder or improve subsequent measures of strength, power or speed. Many of the studies in this review DID NOT incorporate a warm-up routine…so it’s practical effectiveness is definitely in question.
When it comes to SS stretching in combination with a warm-up, performance either decreases or there’s no real impact. The stretch duration plays a role here. In other words, most studies that had participants hold a stretch for longer than 30 seconds noticed a decrease in performance while less than 30 seconds had small, insignificant changes in performance. The bottom line here is that SS just prior to training or competition won’t help performance and depending on intensity and duration, could actually impede it.
On the other hand, when performing DS as part of a complete warm-up routine, IMPROVEMENTS in a variety of performance outcomes have been seen. These include shuttle run times, medicine ball throws for distance and vertical jump heights (Behm 2011). Why is this the case? One reason being that most dynamic stretches have similar movement patterns to those encountered during sport AND at similar movement velocities. DS also seems to affect muscle & body temperature and has a role in stimulating the nervous system, providing further evidence for their implementation in a thorough tennis warm-up.
STRETCHING DURING THE WARM-UP AND TENNIS PERFORMANCE
The ITF (International Tennis Federation) recommends that static stretching be replaced with dynamic stretching. This is a good recommendation…to an extent. Let me explain.
Three studies on tennis serve performance and stretching have been conducted. Knudson et al (2004) saw no effect on tennis serve performance (in terms of both serve speed and serve accuracy) following a SS protocol. In other words, there was no increase or decrease in these measures. Gelen et al (2012) had elite players perform 4 different warm-up protocols on 4 different days and analyzed serve performance after each warm-up. The 4 methods were 1) No warm-up, 2) a static stretching routine, 3) a dynamic stretching routine and 4) a ballistic plyometric routine. Figure 1 shows a detailed description of the study and includes the 4 warm-up methods:
What were the results? You probably guessed it – the MOST effective outcome occured after the ballistic plyometric protocol with a serve speed increase of 3.3%. The second highest was the dynamic exercise method (a 1.23% increase) followed by the no warm-up and static stretching protocols. SS had the lowest serve speeds out of all groups. So based on these results, the ITF has a point, static stretching should probably be replaced by dynamic stretching (and ballistic activities…but more on this later in the post).
Finally, Ayala et al (2016) conducted a very interesting study. They investigated the effects of static stretching and dynamic stretching on a variety of performance measures (20m sprint, countermovement jump [CMJ] and serve speed/accuracy) at 3 different time points – just prior to tennis play, 30 minutes into tennis play and 60 minutes into tennis play. It’s important to note that both warm-ups included light aerobic exercise as well as a variety of ballistic movements AND all players performed both protocols (on different days). Four things you need to know about the results of this study:
Overall, in terms of performance in all tasks (sprint, jump, serve) dynamic stretching was superior compared to static stretching.
SS had a negative impact on serve and jump height when tested just prior to tennis play and at the 30 minute interval.
When tested again at the 60 minute mark, serve and jump height performance seemed to level off – i.e. there was no longer a negative effect.
The DS protocol seemed to produce consistent results across all performance tasks just prior, 30 minutes after and 60 minutes after tennis play.
SHOULD THE TENNIS WARM-UP FOCUS ONLY ON DYNAMIC STRETCHING AND ELIMINATE STATIC STRETCHING ALTOGETHER?
Ok so by this point we’re not that surprised that DS was more effective than SS as a warm-up modality but what’s interesting about the study by Ayaya et al (2016) is that the negative effects of SS started to subside around the 30min mark and were back to ‘normal’ at the 60min mark. This study isn’t the only example. Others have seen decreases in strength after static stretching with normal levels returning between that 30min-60min range. Many authors have suggested that this is due to both mechanical and neural factors but the exact mechanisms are not yet known. In any case. from a flexibility perspective, this has important implications – especially for players with mobility restrictions. Here’s why.
AN EXAMPLE – THE TENNIS HIP
Let’s say you or your player, like many tennis players, have hip restrictions. You probably want your hips to function more effectively during tennis play. From a movement perspective, the muscle groups around the hips are our biggest power generating areas. When it comes to the production of power in serves and groundstrokes, without the ability to effectively disassociate the hips from the lower and upper body, power will be limited. Remember the concept of the kinetic chain…well it’s optimized when joints can act like joints and move independent of one another.
The research on hips in tennis, however, is unclear. Three main studies exist but all 3 are descriptive. Below you’ll find a summary of the results from the 3 hip studies – 2 of the 3 studies included male and female players (all competitive, ranging from junior to pro [ATP/WTA]) while the 3rd study analyzed WTA female players only.
(Note – All values are in degrees. Also, SD refers to standard deviation and signifies a range between lowest and highest values.)
Table 1. Internal, External and Total RangIzbqK21qDA[Lȳ