I’ve decided that one of my key goals in 2016 is to improve my serve. More specifically, I want to add power/pace. In order to make this measurable without investing in a radar gun, I’ve set a specific goal to be able to consistently hit the back fence on one bounce by the end of the 2016 season. If I can do this, which I can’t do now, it will mean I’ve added power to my serve.
To begin, this post will analyze my current first serve. I took a video of myself serving in October, and haven’t done any serving since then, although I have started some off-court training which will be probably more important. More on that below.
Some notes on my serve, from a results perspective (i.e. disregarding technique)
- My first serve is fairly consistent. Without tracking stats, I probably hit 75% of my first serves in, and can place them to some extent
- My first serve has some spin on it which gives my opponents some trouble
- I have a reliable second serve with lots of spin (slice) but no power
- My right shoulder hurts after hitting a lot of serves
- I have trouble flattening out my first serve
- Both my first and second serve lack power
- I can only reliably hit slice, not kick
I’ve taken quite a few live lessons and no coach has ever really said there is anything wrong with my basic technique. I’ve heard things like:
- bend your legs more
- toss the ball further to your right
- keep your head up longer
- use a slightly eastern forehand grip to flatten your first serve
To me most of these are small adjustments to be made to a serve that is 90% correct already, but they will only marginally help a fundamentally bad serve (if at all – bending your legs more will not help a serve in which the kinetic chain isn’t functioning properly, like mine – more on this below). Most likely it’s not that my coaches thought my technique was perfect, but, as I’ve found with many strokes, they assume I’m not looking to completely break my serve apart and start from scratch in order to develop perfect technique, and so were suggesting small changes that might help.
I took some videos and sent one to Jeff Salzenstein for analysis as part of a video course I purchased from him. While I knew there were some problems with my form (such as not having my tossing arm vertical in the trophy position and having a very inconsistent toss), since live coaches have said that my overall technique is fine, it came as quite a shock when Jeff told me that I don’t even get into the trophy position! Looking at the video, he is completely right. I’m continually amazed at how much video analysis shows us and how crazy it is that all coaches aren’t using it. Watching my video at regular speed, my serve doesn’t look too bad (at least to me and apparently some other people), but by slowing it down I’m seeing many things I’m doing wrong. The trophy position is the most obvious and a huge one that needs to be fixed, but there are other problems that I’ve identified by comparing my videos to some of Federer’s and by reading up on serve mechanics and these are preventing me from serving the way I want to.
I’m showing stills from the videos of my serve and from two videos of Roger Federer serving (why not learn from the best?) and underneath I am comparing them to look for differences. The purpose of this post is to serve as a baseline that I can come back to at the end of 2016 for comparison.
Jeff pointed out that there is no reason for me to start with my racquet so high and in front of me. It just adds tension into my arms needlessly. Tomaz at Feel Tennis discusses how we should use momentum to swing the racquet head back, and if my arms and shoulder are stiff this is harder. Should be an easy fix. But at least I do have my weight forward on my front foot, like Roger.
Here you can see a couple of differences:
- My palm is facing up (parallel to the court) while Roger’s is perpendicular to the court.
- Roger’s racquet face is directed at the net while mine is clearly opening up towards the right side fence (particularly noticeable in the back-view image).
- Roger’s hips are pointed towards the side fence with his knees relatively square, while his shoulders are turned slightly towards the back fence. This means he is starting to coil his shoulders relative to his hips which is storing energy (similar to the forehand shoulder turn). My hips are angled towards the back, basically the same as my shoulders, so I’m not generating this stored energy.
Midway between Release and Trophy Position
This image again shows that my racquet face is opening up towards the side/back fence while Roger’s is staying closed. Roger also has his racquet arm higher than mine, parallel to the court surface.
Differences here are:
- My racquet face is open almost towards the back fence.
- Roger’s left arm is vertical, whereas mine is angled towards the net and right side fence.
- My hips and shoulders are facing more towards the back. My knees are bent in the same direction. Roger’s shoulders are facing the same direction as mine, but his knees are clearly bent forwards and his hips are somewhere in between. This very clearly shows that Roger’s body is coiled whereas mine is not.
- My trunk is fairly vertical, whereas Roger’s is leaning back. He has his pelvis tilted with his hips thrust forward which makes his body almost a straight line from front knee to shoulders. There is an obvious bend at my waist with my hips more neutral, directly underneath my shoulders.
The main differences here are in the angles of our arm segments. Roger’s upper arm and forearm form a 90 degree angle that is almost lying in a plane that is parallel to the court. My upper arm is angled upwards and my upper and forearm form more like a 30-45 degree angle which results in my racquet being dropped directly behind me (not visible in the side-view image).
Racquet Drop to Contact
Key differences here are:
- My hips, shoulders and knees are turned a little more towards the net than Roger’s, who is still quite sideways facing.
- My upper arm is angled towards the net while Roger’s is still vertical.
- My upper body is angled forward toward the net and also left towards the left side fence while Roger is only slightly angled forward toward the net and quite vertical in the left-right dimension.
- My strings are facing open towards the sky while Roger’s are nearly perpendicular to the ground (actually slightly closed in the back-view image).
Just Before Contact
I thought this image was worth adding since it shows that my racquet face has opened towards the ball while Roger’s is still approaching it “on edge” when we’re about the same distance from the ball.
The main differences here are
- My body is angled to the left while Roger’s is not.
- I seem to contact the ball further in front of me.
- My shoulders are facing the net while Roger’s are still facing largely sideways (more visible in back-view image).
In the back-view image Roger’s racquet arm seems to be slightly bent while mine is straight. Also, my racquet is facing more towards the ground while Rogers is facing the right-side fence. Remember that his racquet was more on-edge just before contact than mine, and is now more on-edge right after contact as well (on the other edge!), so he has done this pronation movement more quickly than me. I pronated, but not as much and not as quickly. I seem to have a more linear swing path.
A couple of things to note:
- In the back-view image I am definitely still leaning to the left and my right leg is thrown out to the right for balance.
- In the back-view image Roger’s racquet clearly stays out to the right side of the body while mine finishes directly in front of me
- In the back-view image Roger’s hips and shoulders are still sideways while mine are facing the net.
- In the side-view image, Roger has not even landed yet when his racquet is pointing down, indicating that he has more hang time than me and/or his racquet moves fast than mine.
Conclusions and Discussion of the Kinetic Chain
Putting this all together, here is a list of what I think are the key problems with my serve:
- Opening my racquet face to the back fence during take-back and trophy position
- No coil in my hips/trunk/shoulders to store energy
- Unusual arm segments positioning in the racquet drop
- No pelvic tilt
- Not getting a vertical tossing arm during trophy position
- Early and slow pronation of my forearm during contact phase
- Hips and shoulders facing forward at contact
- Linear swing path
- Body tilting to the left (off-balance)
- Slow racquet speed
Well it’s a wonder I can get the ball over the net! This seems like a pretty daunting list to tackle, but based on some reading I’ve been doing, I don’t think these problems are necessarily independent of one another. It’s likely that some of them are causing others, so eliminating one problem will eliminate some resulting issues.
I’ve found a few good scientific papers on serve mechanics. This one is a little difficult to understand if you, like me, aren’t an anatomy whiz. It has some great illustrative images though and what I do understand does explain the serve well. Another, less technical, paper is “The 4000-watt Tennis Player: Power Development for Tennis” from the Journal of the Society for Tennis Medicine and Science. This article discusses the importance of the kinetic chain in tennis.
I’m not going to get into the specifics of the kinetic chain and it’s importance in tennis other than to say that a sequenced chain of events must occur to transfer force from one segment to the next. This chain is what allows us to use our strong legs and trunks to cause fast racquet speeds at our smaller wrist joints. The interesting part to me is what happens when the chain breaks down: Decreased performance (velocity/power) or injury (higher loads are placed on joints further down the chain to compensate for the reduced upstream transfer). In my case, my serve lacks velocity/power, and my shoulder hurts (deltoid region) when I hit a lot of serves. Oh, and I’m also recovering from a torn TFCC and ECU sublaxation/tendinosis in my wrist. Could these things be caused by a breakdown in my kinetic chain? According to the STMS paper, the breakdown results from injury, acquired deficits in flexibility or strength, or muscle imbalances. The most common deficits involve the hip, trunk, and shoulder.
Some of the statistics in the STMS paper are (cited from various studies in the article):
- If all segments after the broken one function normally and are activated normally (no compensation) then there will be a decrease in energy supplied to the ball.
- If “catch-up” or compensation is employed to make up for the breakage further down the chain, then a 20% decrease in trunk kinetic chain requires a 34% increase in shoulder velocity or a 70% increase in shoulder mass to get the same energy at the end of the chain.
- Half of arthroscopically (surgically) demonstrated posterial labral tears (shoulder) were associated with hip rotation inflexibility (i.e. if we don’t fix our hip rotation inflexibility we can wind up with a tear in our shoulder!).
I recently began working with a personal trainer, and he performed an assessment of my strength and mobility. Here are the key results, with some pictures I took to illustrate:
- Restricted ankle mobility (Left 3”, Right 2”)
- Restricted hip extension + External Rotation (lateral pull on Thomas Test, difficult to push knees out in squat)
- Restricted Shoulder Flexion
- Restricted Shoulder Flexion/Abduction/External Rotation + Extension/Adduction/Internal Rotation (10” both sides)
- Restricted Thoracic rotation (ability to rotate around my upper spine)
So I basically have restricted movement at my hips, in my trunk and in my shoulders. When I try to serve harder, I’m a) adding more load to already dysfunctional body parts and/or b) compensating for restrictions further down the chain which adds more load to smaller segments and leads to injury. Instead of generating effortless power in my serve in my legs, the energy I’m generating there is progressively lost at each link in the chain that doesn’t function properly. I end up muscling the ball with my arm, which results in weak serves and injuries.
Looking at my list of serve problems, I think that only one of them is easily fixable with a change to my technique, and this is keeping my racquet face closed during take-back and trophy position. The rest are largely due to my strength and mobility issues, so they are much harder to address, but crucial if I want to serve like Roger, and, more importantly, stop hurting myself.
So my plan of action is to spend a lot of my effort improving my strength and mobility before really worrying too much about my technique. I strongly suspect that at least some of the deficiencies in my serve will disappear once my body is working the way it should be, and some of the improvements I want to make likely aren’t even possible without increased strength, flexibility and mobility (such as pelvic tilt, hip rotation and shoulder positioning). On court, I’ll be working on the correct trophy position, staying sideways longer for a shoulder-over-shoulder circular motion rather than a linear one, and keeping my wrist loose and pronating at the right time.
At the end of 2016 I’ll post a similar analysis and see what I’ve been able to do. Maybe by then I’ll be giving Roger some tips 🙂
I’d love to hear what you think. Any tips or arguments are most welcome. Has anyone else out there done a comparison like this?