A common problem seen in tennis players is cramping.  Cramping is seen during Grand Slams tournaments when matches are played in hot and humid conditions. They are very common to see in longer physical matches. In lower levels of tennis such as league or recreational play it is common due to lack of practice time during the week or lack of fitness.  A lot of the time cramping is preventable with proper hydration, nutrition and physical preparation leading into a match or tournament.

1. Hydration - Dehydration is one of the main causes of cramping. The majority of athletes walk into a match or practice already dehydrated. During a match an individual can lose between 1.5 to 3 liters of sweat. The main element lost in sweat is salt. An easy test to see how much an individual sweats is to wear a dark colored shirt. Once the practice or match is complete look for white stains around the shirt, as this is a sign of the amount of sodium lost during the practice or match. The more white (salt) the shirt has is the heavier a sweater he/she is. Consuming a sports drink such as Gatorade will help prevent cramping. If he/she does not like a sports drink, adding salt to your water or drink of choice is a good way to substitute the sodium lost during play. Recent research has shown that drinking Alkaline water also helps keep a higher PH level in the body. This allowed for more efficient utilization of lactate after high intensity exercise. Also remember that hydration begins before the match or practice.
   
   
2. Nutrition – Nutrition plays a big role in an athlete’s performance. Tennis is a high intensity sport with short points (5-20 seconds) and long breaks (20-25 seconds). Carbohydrates are very important for a tennis player. They provide immediate energy during a match. Gel packets and sports drinks are commonly seen being consumed by tennis players because they provide quick energy. Recent research shows that consuming 16g of glucose improved endurance by 14% compared to drinking only water. A suggested consumption of 20-90g of carbohydrates is recommended per hour. This all depends on your ability to digest a gel or sports drink during competition. It is also important to consume enough calories before and after playing. Consuming the right balance of carbohydrates, fats, and protein in your diet is important to have enough energy throughout the practice or match and prevent cramps.

 

1. Physical Preparation – The final piece to the puzzle is fitness. For most professional athletes this is not a problem, but for recreational players it can be. Most recreational players participate in a league or play with friends once or twice a week. The problem is that if they don’t do any work in the gym or supplemental fitness when they aren’t playing tennis they run the risk of cramping during longer matches. Tennis is a high intensity sport. Combined with the pressure of winning and possible hot and humid conditions there is a high risk of cramping no matter the level of he or she competes in. He or she should try and exercise 2-3 times a week outside of a practice or match in order to improve their fitness levels. This will help prevent cramps muscle fatigue which can lead to cramping.

 

1. Emotional & Mental Preparation – Most cramping occurrences happen during matches and competitive environments. Therefore, it is very important to not overlook the stress response and the impact it has on muscle function and physiological responses that contribute to the exercise associated muscle cramping timeline and mechanical process. Working on breathing routines, focusing on the process rather than the outcome and having overall general routines is very beneficial in this perspective. Here is a great resource that has many lesson plans and practical examples on how to improve the emotional and mental skill development  https://www.amazon.com/USTA-Mental-Skills-Drills-Handbook/dp/1606790803
   
   

In conclusion, the 4 main causes of cramping are a lack of hydration, nutritional deficiencies, physical preparation and emotional/mental preparation.

​Here is another great resource from the iTPA on Cramping in Tennis:
Cramping in Elite Level Tennis - http://itpa-tennis.org/itpa-blog/cramping-in-elite-level-tennis
Calambres musculares en el tenis http://itpa-tennis.org/itpa-blog/muscle-cramping-in-tennis-espanol
 
Resources:
https://link.springer.com/article/10.2165/00007256-200434010-00002
https://www.ncbi.nlm.nih.gov/pubmed/29158619
https://link.springer.com/article/10.1007/s40279-014-0148-z
http://www.sciencedirect.com/science/article/pii/S1440244003800051
 

by​ Patrick Aubone, CTPS & Dr. Mark Kovacs, CTPS, MTPS

For the first time in the Open era a Grand Slam lacked major star power on the men’s side with nearly half of the top players being unable to play due to injury. The list of casualties from the top 10 was pretty big: Andy Murray (hip), Novak Djokovic (elbow), Milos Raonic (wrist), Kei Nishikori (wrist), Stan Wawrinka (knee). Five of the top 11 players in the world missed the US Open this year. Last year Roger Federer took the final 6 months of the year to recover from an off court knee injury while Rafael Nadal has been battling injuries for years.
​
This year at Wimbledon, the men’s draw alone had 7 first round retirements and 11 total in the first 2 rounds. According to an ESPN, since Wimbledon 2007 there has been 237 retirements in Grand Slam tournaments for men alone.  This is an astounding number!

"Are all these retirements due to the schedule? Too much travel? Off court stress? Ineffecitve off-court or on-court training? Looking at the ATP Tour website, post US Open, Alexander Zverev and Roberto Bautista Agut lead the top 10 players in matches played with 76 and 71. That doesn’t take into account the upcoming indoor season and year end tournament.  Nadal is a close third with 67 matches played, Federer is at 41, and Del Potro is at 46. Federer has only recently had some injury problem with his knee and most recently his back but prior to age 33 he only experienced an ankle issue one year and still came back for the season ending tournament. Del Potro aside from his multiple wrist surgeries has had an injury-free career though he is still young at 28. Outside of the top 10, Goffin and Theim are the only players above 75 matches.
How much is too much?

The players travel 25-35 weeks a year between tournaments, preseason camps, and home visits. While some individuals can argue that Courier, McEnroe and Lendl all played 85+ matches in the past, there are many variables that have changed. The athletes are stronger, faster and fitter than ever. Matches are going 5+ hours in Grand Slams with the winner having 36 hours to recover before playing again. The physical toll on the athlete’s body after these matches is tremendous. Technology has played a part in developing more powerful racquets allowing players to hit harder and add more spin to the ball.  It has also played a big part in the recovery process with such innovations as compression garments by 2XU & Body helix, Pneumatic Compression like Normatec or Recovery Pump Boots and non-fatiguing Muscle Stimulation machines like the Marc Pro Plus. Most are not even well versed in the various other aspects that contribute the the stress and recovery process.

Here is a good resource from the USTA with some in-depth review of Recovery in Tennis. Here is the Recovery in Tennis Coaches, Parents and Players Booklet - http://s3.amazonaws.com/ustaassets/assets/1/15/recovery_project_coaches_booklet.pdf 

If you are interested in reading more in-depth science around tennis recovery here is the expert written book on the topic (398 pages) edited by Drs. Kovacs, Kibler and Ellenbecker:

​http://assets.usta.com/assets/1/dps/usta_master/sitecore_usta/RECOVERY%20PROJECT%20FINAL.pdf

Even though the increase in top star players injuries is the focus of many articles (see below), the actual yearly data of overall injuries on the ATP World Tour is actually rather consistent with years past. It is just that we have for the first time a large percentage of the Top 10 players unable to play a major championship (the US Open). As a result, it attracts major attention and shines a light on injuries in the sport. However, it is always important to look at the data and understand what is actually happening.

https://www.nytimes.com/2017/07/06/sports/tennis/players-pull-out-at-wimbledon-and-calls-for-reform-flood-in.html?mcubz=0&module=ArrowsNav&contentCollection=Tennis&action=keypress&region=FixedLeft&pgtype=article

http://www.nytimes.com/2011/09/04/sports/tennis/pro-tennis-season-can-nearly-a-year.html?mcubz=0
​
http://www.atpworldtour.com/en/performance-zone/win-loss-index

by Oliver Stephens: 

ITPA Master Tennis Performance Specialist, PTR Master of Tennis (Performance and Development), USPTA Elite Professional

As a Tennis Professional, I have been blessed to have some amazing educational opportunities in the last several years.  None more so than my involvement with the International Performance Tennis Association (iTPA).  I went all in with this organization and took all three of their courses, culminating with the Master Tennis Performance Specialist Course.  All three courses were a deep dive into the science behind tennis specific fitness training, including injury prevention, power training, tennis specific endurance training, training 10U players, seniors, periodization and planning, tennis movement, stroke analysis and so much more. 
 
The courses were a great chance for me to learn in great detail some of the more advanced techniques used by the top professionals in the industry.  To learn from Dr. Mark Kovacs is an amazing opportunity in itself, but it was equally amazing to have the opportunity to learn from some of the other amazing professionals on the courses such as Jonny Fraser, owner of Science in Tennis and Satoshi Ochi from the USTA. 
 
As I said, we took a deep dive into the detail but the one thing I noticed was the emphasis on getting the fundamentals correct.  On the MTPS course for example, we discussed how some of the best 18U tennis players in the country couldn’t execute a simple box jump with the correct form, which would be an indicator of high injury risk later in their career.
 
We spent a lot of time talking about how important a good foundation and solid fundamentals are, and we also discussed how important it is to get the fundamentals trained early on but also that it is not too late to train fundamentals later in a player’s career. 
 
I would like to go through three of the most common exercises that I feel that all tennis players should be able to perform and how to progress up to these exercises by getting the fundamentals correct from the beginning. 
 
Exercise #1
 
Box Jumps
 
I see tennis players performing box jumps all of the time and it makes me cringe.  Its often not the jumping up that is so bad, it’s the landing that looks so bad.  I so often see players landing in a Valgus position (see below):

This position is obviously incorrect, and if performed over time, will put tremendous stress on the ACL and other joints and muscles.  This condition is sometimes an orthopedic issue, and of course, you should refer to a specialist to see if this is the case.  However, I have also found that this is sometimes a condition that can be trained to be better by increasing muscular strength in the Abductor area and by simply training the athlete to be more in control of their body. 
 
Here is my three-step progression that I have had good success with my athletes with:
 
 
1a.             Can the athlete squat and pick up a medicine ball up off the ground with correct form?  
 
Very simply, train your athletes to be able to pick up a 4-6lb Medicine ball up from the floor.  The emphasis of course should be keeping the spine neutral and using your legs to do all the work while keeping the knees in the correct position.  You will be amazed at how many of your BEST tennis players won’t get this right the first time!  As I mentioned above, it may simply be an awareness issue that the athlete just needs to fix with correct training and consistent re-enforcement.
 
1b.       At the same time that you are working on the first progression, you can also             incorporate some lateral and forward monster walks into the fitness     program.  This will strengthen the hip Abductors, which will help your athletes keep their form in more advanced exercises.  Make sure that you don’t apply too much resistance, start with lighter bands and work your way up.  I even have my athletes begin without any resistance at all in order to get the form correct from the start.  I would recommend 3 sets of 12 monster walks 2-3 times a week as part of their fitness routine.
 
2.         Train your athletes to jump and land correctly.  Without any boxes, steps etc, your athletes need to be able to start with their feet 12-18 inches apart, go      into a shallow squat and jump 6-12 inches in the air and land with correct             form.  This exercise is to be done slowly and with an emphasis always on posture and correct form.  When your athletes can perform this well, have them jump (slowly) over a 6-12 inch hurdle.  Always remember, you can always go back and work on more simple progressions (regressions), if your athletes are struggling with form.   
 
3.         Before you progress to box jumps, work on box landings.  Have your athletes           stand on a low box or step and then jump down and land with the correct form.  Your athlete must be able to perform this 10 times without losing their form before you move onto a traditional box jump. 
 
            Remember, don’t be afraid to go back and regress if your athlete loses his or her form and take your time with these exercises.  It may take a few months to have your athlete box jumping efficiently. 
 
 
Exercise #2 Forehand and backhand Medicine Ball Toss, Deep, Short and Wide.
 
This is a very common exercise and for good reason - it is great for tennis players if performed correctly!  However, so often it is not.  Here are the basic fundamental rules to perform an effective Medicine Ball toss. 
 
 

1. Don’t go too heavy!

 
Start with a lighter weight, even a soccer ball in order to get the form correct      from the beginning.  In fact, I wouldn’t even have the players catching and throwing at the beginning, rather, I would have them simply shadow the strokes with the light ball in order to work on PERFECT FORM.
 
 

1. Posture is everything in this exercise:

 
As in the point above, overloading of the athlete, or, too many repetitions will cause athletes to lose their form and especially lose their posture.  Always remind your athletes of the importance of good posture in all their exercises.   This is especially true when you start to incorporate catching and throwing the weighted ball.  Can your athletes keep good posture when they catch the ball as well as when they throw it back?
 

1. Make sure they are in the correct stance for the ball they are receiving:

 
 When they move to a shorter throw they should use a closed stance.  When  they move to a neutral ball, a neutral stance and when they move to a wide ball, an open stance.  Be precise with your feedback and make sure the    athlete is aware of this requirement.   
 
In these kind of exercises the athlete knows what kind of ball they are receiving (closed skill training).  Therefore, we must make sure we are getting the athletes working as accurately as possible and performing the  skills as close to perfection as is possible. 
 
Exercise #3:  Cone Drills
 
Many of you will be using cone drills with your students such as figure 8’s, wide shadow strokes and forwards and backwards recovery drills.  Again, these are great drills and you should use them often.  But we MUST make sure we get the fundamentals right.  Here are some tips to make these drills   fundamentally sound:
 

1. Make sure your athletes are in an athletic ready position before they begin the exercise.   Do they have good posture?  Are they on the balls of their feet and do they generally look ready to go?

 

1. In the figure 8 drill, have your athletes do a split step at the beginning of every figure 8.  I have found that this small detail makes the drill so much more tennis specific.  To quote the iTPA study guide directly “The closer the athlete can experience movements, feelings and situations that will be experienced during competition, the better prepared the athlete will be.”
   
   
2. When performing wide recovery drills, focus on the specific footwork that the recovery should have.  For example, on a ball that you only have to move a few feet for, you make a simple side step to recover.  For a ball that brings you wider, say 15 feet or so, you should have a crossover step as your first recovery movement and for a very wide ball that takes you outside the singles sideline, the athletes should be trained to turn and run a few steps until moving into a more traditional side step recovery movement phase. 
   

These are all simple points that I have tried to make.  I hope you will join me in teaching the FUNDAMENTALS well and not moving your athletes too quickly through the progressions of your exercises and workouts.  Let them walk before they can run and in the long term, you will see better results than if you tried to build Rome in a day!
 

By Patrick Aubone

For the first time in as long as I can remember a Grand Slam lacked star power on the men’s side. The list of casualties from the top 10 was pretty big: Andy Murray (hip), Novak Djokovic (elbow), Milos Raonic (wrist), Kei Nishikori (wrist), Stan Wawrinka (knee). Five of the top 11 players in the world missed the US Open this year. Last year Roger Federer took the final 6 months of the year to recover from an off court knee injury while Rafael Nadal has been battling injuries for years.

This year at Wimbledon, the men’s draw alone had 7 first round retirements and 11 total in the first 2 rounds. According to an ESPN, since Wimbledon 2007 there have been 237 retirements in Grand Slam tournaments for men alone.  This is an astounding number!

Are all these retirements due to the schedule? Too much travel? Off court stress?  Looking at the ATP Tour website, post US Open, Alexander Zverev and Roberto Bautista Agut lead the top 10 players in matches played with 76 and 71. That doesn’t take into account the upcoming indoor season and year end tournament.  Nadal is a close third with 67 matches played, Federer is at 41, and Del Potro is at 46. Federer has only recently had some injury problem with his knee and most recently his back but prior to age 33 he only experienced an ankle issue one year and still came back for the season ending tournament. Del Potro aside from his multiple wrist surgeries has had an injury-free career though he is still young at 28. Outside of the top 10, Goffin and Theim are the only players above 75 matches.

How much is too much?

The players travel 25-35 weeks a year between tournaments, preseason camps, and home visits. While some individuals can argue that Courier, McEnroe and Lendl all played 85+ matches in the past, there are many variables that have changed. The athletes are stronger, faster and fitter than ever. Matches are going 5+ hours in Grand Slams with the winner having 36 hours to recover before playing again. The physical toll on the athlete’s body after these matches is tremendous. Technology has played a part in developing more powerful racquets allowing players to hit harder and add more spin to the ball.  It has also played a big part in the recovery process with such innovations as compression garments by 2XU & Body helix, Pneumatic Compression like Normatec or Recovery Pump Boots and non-fatiguing Muscle Stimulation machines like the Marc Pro Plus. We aren’t even taking into account Central Nervous System (CNS) fatigue, travel related fatigue, family and social fatigue and other aspects of being a year round traveler. Is it time to change the calendar or maybe slow down technological advances in racquets and strings, adjust the court surfaces, etc?

Even though the increase in top star players injuries is the focus of many articles (see below), the actual yearly data of overall injuries on the ATP World Tour is actually rather consistent with years past. It is just that we have for the first time a large percentage of the Top 10 players unable to play a major championship (the US Open). As a result, it attracts major attention and shines a light on injuries in the sport. However, it is always important to look at the data and understand what is actually happening.

https://www.nytimes.com/2017/07/06/sports/tennis/players-pull-out-at-wimbledon-and-calls-for-reform-flood-in.html?mcubz=0&module=ArrowsNav&contentCollection=Tennis&action=keypress&region=FixedLeft&pgtype=article

http://www.nytimes.com/2011/09/04/sports/tennis/pro-tennis-season-can-nearly-a-year.html?mcubz=0

http://www.atpworldtour.com/en/performance-zone/win-loss-index

By Ale Oliveira, CTPS

Atlanta, Georgia hosted the 2017 International Tennis Performance Association World Tennis Fitness Conference on July 22nd and 23rd. The conference was organized by International Tennis Performance Association (iTPA), and included world class faculty who are true leaders in the field of performance enhancement and injury prevention for tennis. Listed below are just some of the exceptional professionals who spoke that weekend:

• Sue Falsone - World Class PT and ATC
• Gil Reyes - Trainer and Mentor for Andre Agassi
• John Downes – Leading Chiropractor and Director Emeritus, Life Sport Science Institute
• Jason Vescovi – PhD, Leading Sports Science and Medicine expert for Tennis Canada
• Clay Sniteman – PT, ATC, Medical Director of the ATP Tour
• Andy Britton - Ohio State University Strength and Conditioning Coach
• Aylin Seyalioglu  - DPT, Tennis Specific Physical Therapist and Young Athlete Expert
• Rodney Harmon - 2008 Men’s Olympic Tennis Coach, Currently GA Tech Women’s Tennis Coach
• Mark Kovacs – CEO, Kovacs Institute and Executive Director of the International Tennis Performance Association (iTPA) – conference chair
• Performance experts from The Ohio State University, The University of Michigan, The University of Georgia, Georgia Tech.

 
Conference Day 1 The day started off with Mark Kovacs sharing his knowledge on Advanced Biomechanics of tennis strokes and movement. One of the top professionals on the subject, Dr. Kovacs demonstrated an up-to-date analyses and protocols on how to work with tennis athletes on and off the court. Later in the morning, a panel, composed of highly respected tennis coaches and strength and conditioning coaches from the collegiate and professional tennis world, gave the conference’s participants the opportunity for a Q&A time and focused around optimizing performance in the collegiate setting. Panel members’ promoted an educational discussion based on their daily protocols, good and bad habits and how to maximize athletes while preserving their health. It gave the participants real life examples and different ways to approach.

Sue Falsone, who was the first female Head Athletic Trainer for a Major League Baseball (MLB) team – the Los Angeles Dodgers, shared her varied knowledge in dealing with overhead injuries. Falsone demonstrated new techniques and approaches that minimize injury risk and restructure the athlete’s body (posture) to maximize performance. She has presented on national and international level conferences in areas focusing on pillar strength, integration of physical therapy and performance training, and comprehensive kinetic chain assessment and rehabilitation.

Gil Reyes energized the room with his enthusiasm while sharing techniques and approaches he has collected throughout the decades working with worldwide legends in the tennis world including Andre Agassi, Simona Halep, Angie Kerber, Genie Bouchard, Jo Wilfred Tsonga and Fernando Verdasco. Reyes is the long time trainer and mentor to Andre Agassi. He worked with Andre during his entire pro career and also held the position as Strength & Conditioning Coach for the 1990 National Championship UNLV Runnin’ Rebels Basketball program. Reyes shared his experiences on the best way to retain the maximum level from your athletes under exhausting circumstances. His focus was on the important of the development of strength for the tennis athlete.

An outstanding practical session was held was held later in the day. Guest speakers and conference participants were able to discuss, learn and share new information and techniques touching all topics of discussed that day. Dean Hollingsworth demonstrated tennis plyometric protocols focused on power and speed. Hollingsworth is an established, highly regarded fitness consultant with more than 20 years of experience. He has worked with youth and young adults focusing on speed, agility, coordination and strength. Following Hollingswoth, Dominic King (Head of Athlete Development at Every Ball Tennis) spoke on the importance of on the road training for tennis. He opened up on how to optimize time and space to promote a high level program, but not forgetting recovery and time management during those tournaments. Andy Britton used the conference room as a mini collegiate weight room to demonstrate the best protocols performed by tennis athletes. Britton has served as a member of the strength and conditioning staff for the Ohio State Buckeyes since 2005.

Day 1 ended with the social and networking event which is always a great way for all the experts attending can talk shop in a relaxed setting.

Conference Day 2 The morning started with the hot topic of treatment techniques used in the ATP World Tour. Clay Sniteman lead the discussion and focused on the top 5 lower body and core issues seen on the tour lately. Clay serves as the ATC and PT for the World Tennis Professional (ATP), and has experience working with the Olympics and the World Champions Chicago Sledge Hockey Team.

Dr. Kovacs then interviewed Reilly Opelka. Reilly is a former junior Wimbledon Champion and one of the top rising stars on the ATP World Tour. Dr. Kovacs has been working with Reilly since the age of 13 and they discussed his development and the goals ahead from a physical and performance perspective.

Jason Vescovi, who oversees Sport Science for Tennis Canada, walked through his expertise on the new technology protocols are being used in sports, and how to quantify loads in tennis: with or without technology. Aylin Seyalioglu followed up with a great talk on the Female tennis player and how to work and train female athletes from a biomechanics and injury prevention perspective.  Leading ATP and WTA nutritionist, Page Love, shared her nutrition knowledge. Love focused on building muscle for the competitive athletes and the innovated and reliable protocols that promote muscle rebuild. Participants also had the opportunity to learn more about the ultimate recovery devices out in today’s market. World recognized companies such as Marc Pro, RP sports, Normatec and Rapid Reboot showcases their products and demonstrated new releases and protocols.

The 2017 conference was a success. The weekend’s agenda provided attendees the opportunity to learn from the best professionals out in today’s tennis specific performance and injury prevention environments. This is a must attend event on the tennis calendar for any person who trains, treats, rehabs tennis athletes at all levels of the game!

by Jonny Fraser, CTPS, MTPS 
Owner of Science in Tennis, Strength and Conditioning Coach Claudio Pistolesi Enterprise

The aim of this group of articles is to provide evidenced based practical considerations on how LTAD can be implemented within tennis clubs, regardless of facilities, number of players or coaches working in the program. Part one emphasised the importance of how motor skill and strength development should work alongside the delivery of tennis coaching. As discussed strength is a key component of motor skills (Lloyd et al., 2016). The second consideration focused on using tennis clubs to promote lifelong health and wellbeing. Strength and conditioning, mental skill training, nutritional education and lifestyle support alongside coaching provides a holistic approach to health and wellbeing of young people. We will look at one more considerations in this part:

Consideration three: monitoring tools can be implemented within programs, with parents and players being educated on their use.
Using monitoring tools considering physical performance, psychosocial wellbeing, growth and maturation should be implemented within long term athletic development programs (Lloyd et al., 2016, iTPA 2012). Factors such as facilities, expertise and cost however may influence the methods used.

Physical Testing
Physical testing allows coaches to determine improvements in physical performance. Testing is likely to focus on areas including speed, agility, strength, power, endurance and movement competency. Procedures and protocols may be adapted to meet the varied ages or the number of players. Testing can occur quarterly or termly, ideally with players tested in a similar environment (such as court surface, temperature and warm up routines). Furthermore, based on the equipment available and expertise testing may vary from the use of a tape measure and stopwatch, to the use of minimal cost Android/iPhone applications (such as My Jump and My Sprint) to the use of high end technology such as Optojump and timing gates. Regardless of what is available if the testing is standardised then the results can provide useful feedback. However not only should the test outcome provide important information. To monitor performance coaches should be aware of movement efficiency. Movement competency can also be assessed, through a check list, looking for important technical components and whether the young athlete demonstrates this (for example as when jumping is the landing balanced). As discussed in Part One, movement competency and body awareness is essential to fundamental movement skills and the development of sport specific skill. 

Growth and Maturation Assessments
It is important to remember that young people should not be trained like ‘miniature adults’ with individual differences both in physical and psychosocial development (Lloyd et al., 2016). Growth and maturation should always be an important consideration when coaching junior tennis players. It is an individualised and dynamic process.  Rapid increases in growth may put players at risk of increased overuse and traumatic injury pre-and during peak height velocity (PHV) (Sluis et al., 2015). Individual differences in maturation should lead to players program being adapted managing volume and session content (Ochi and Kovacs, 2016). In effect during rapid growth rates players are having to 'relearn skills' and learn about their 'new body'. This may be demonstrated by changes in co-ordination. For example, players spatial orientation may be altered due to changes in limb length and thus perception and contact points on groundstrokes may be different.
With permission from parents and players, coaches should regularly measure players height, leg length and weight and monitor this accordingly. Peak height velocity in girls have been noted to be around 8.3cm/year where with boys this increases to approximately 9.5cm/year (Strandjord and Rome, 2016).
The use of non-invasive measures may also provide coaches with estimation of the age of PHV and the predicated height of adult stature (PHA) (Khamis and Roche, 1995, Mirwald et al.,2002). The equation devised by Mirwald et al., (2002) can provide a predictive measurement of PHV using measurements including height, leg length and weight. This has shown to have an accuracy of ± 6 -12 months but may provide a useful tool for coaches to provide greater insight when PHV may be occur.

The equation is available at:
 http://www.kinesiology.usask.ca/growthutility/phv_ui.php.
(University of Saskatchewan, 2017)
Furthermore, awareness of the current maturity of players predicted by PHA may also provide coaches with information about players current growth rates. Khamis and Roche (1995) method takes into account parental heights, height, weight and age of the individual providing a predicted adult height. The method has also been shown to be a reasonable predictor alongside invasive, costlier and medical professional methods measuring skeletal maturity through radiography (Malina et al., 2007). PHV has been shown to occur between 88-96% PHA, with largest gains at around 92% PHA (Cummings et al., 2017). Therefore, having a multitude of data may help provide greater clarity when PHV is occurring. The PHA equation is available at:
http://www.uwmsk.org/stature.html
(University of Washington, 2017)

Therefore, coaches may want to consider the combination of fortnightly to monthly measurements of height, weight and leg length, alongside termly use of equations predicting the age of PHV and PHA. Equations. This will allow more evidenced based considerations when planning training blocks for individual players.
Subjective measure continues to be considered one of the most effective ways to monitor training stress placed upon individual both from chronic (longer term such as over weeks) and acute (one session) training (Saw et al., 2016). Both the Recovery Stress Questionnaire for Athletes (RESTQ-S) and Profile of Mood States (POMS) questionnaire have been shown to be appropriate when working with young athletes (Saw et al., 2016). These questionnaires consider stress, feelings of recovery and mood profile of the individuals. Due to potential time constraints, it would be unrealistic to complete these after each session however coaches, particularly those working with players at high volumes of play, may wish to consider using these fortnightly. Combining this with regular anthropometric measurements may provide a regular monitoring process. 
Coaches working alongside strength and conditioning/sport scientists may also wish to consider devising their own subjective questionnaire suiting the needs of their program and players they support. This may consider areas such as feelings of fatigue, muscle soreness, sleep quality, illness, feelings of stress and motivation, social wellbeing (e.g. time with friends/family) and other parameters they may be affecting the individual’s wellbeing such as school work.

Training Loads

Training load is an important focus when working with junior tennis players in relation to injury risk. In recent years Jayanthi et al., (2013) and Ochi and Kovacs (2016) have suggested age minus one should be the maximum volume of tennis activity hours players should participate in per week. This is further backed up by effective tournament planning which consists playing no more than 18 tournaments per year and two or less per month for players in a Training to Compete Age (Jayanthi et al., 2013, Ochi and Kovacs, 2016). Ochi and Kovacs (2016) continue emphasising the importance of effective long-term planning with junior’s players taking two full days off per week with download weeks of training reducing the intensity and/or volume.

Despite having a range of internal (heart rate) and external measures (GPS) that are often used in sport, subjective measures like ratings of perceived exertion (RPE) (Figure One) continues to be used by top practitioners (Gabbett, 2016). Not only is this a cost effective and simple measurement to use it also allows young people to begin to understand how their bodies develop and what training intensities may feel like. The use of arbitrary units through RPE and Time can give coaches a training load:

RPE (of the player during that session) x Duration of Training (minutes) = Load (Figure 2)
Despite little evidence in tennis and particularly with young individual’s, Gabbett (2016) suggested that players were 50-80% more likely to get injured with weekly training loads of 3000-5000 units during preseason. Of course, with young athletes we should consider these numbers with caution and make no generalisations. However, the use of RPE X Time can be an effective way in which to measure training load, allowing training to be planned and adapted very quickly. Although it is important to state when units increased weekly by more than 10% a greater risk of injury was shown. Therefore, training loads should be well planned, managed carefully with regular download weeks.

Figure 2: Training Load RPE X Time Performance Junior

Technical Elements

A final but obvious consideration is the coaching of effective technique within tennis. Despite there being individual differences in techniques based on anatomical and physiological variations, to maximise performance and reduce injury risk biomechanical principles of stroke production are agreed (Elliott, Reid and Crespo, 2003). However, it may be worth coaches having a 'check list' of effective stroke mechanics which may reduce the risk of injury when coaching junior players. Excellent work has been ongoing focusing on stroke modification following injury (Jayanthi and Tzakis, 2016).  Areas of focus on the serve include reducing lumbar (lower back) extension by less than 20° and that knee bend is greater than 10°. Furthermore, focusing on scapular retraction (shoulders pulled back) and effective torso rotation during the loading phase are also important considerations during the serve (Jayanthi and Tzakis, 2016, Kovacs and Ellenbecker, 2011).  Reducing excessive ulnar deviation (movement of wrist, little finger side dropping excessively to body) and 'wrist led shots' on groundstrokes may also reduce the risk of injury with additional lower body strength to lunge and load through the kinetic chain of the body (Jayanthi and Tzakis, 2016). Coaches with permission of parents may wish to film players and then using applications such as Coaches Eye or Dartfish analyse areas of technique potentially at the start of every term.

The aim of part two of this blog was to provide an overview of how monitoring tools can be used within tennis programs focusing on one of the pillars from the excellent NSCA Position Statement on LTAD (Llloyd et al., 2016). Tennis coaches are at the forefront with players and parents, because of this they are the 'secret warriors' on emphasising how sport science can be integrated into training not only to benefit performance but more importantly for health and wellbeing. Arguably sport science and tennis coaching go hand in hand and should be considered equally important as a collaboration for LTAD. They should not be separate entities and this where the certification process by the iTPA helps bridge the gap.  Not all the suggestions made in this article (summarised in Table One) may be utilised within tennis centres based on the participation levels of players, the available facilities or expertise of the coach. However, as a duty of care to players and to make sure we use tennis as a channel to promote health and wellbeing to young people a robust monitoring system can certainly play its part.

References
Cumming, S.P., Lloyd, R.S., Oliver,J.L.., Eisenmann, J.C., & Malina, R.M. (2017). Bio-branding in sport: application to competition, talent identification and strength and conditioning of youth athletes. Journal of Strength and Conditioning Research. 39 (2), 34-47.
Elliott, B., Reid, M., & Crespo, M. (Eds.) (2003). Biomechanics of advanced tennis. London: International Tennis Federation.
Gabbett, T. (2016). The training-injury paradox: should athletes be trained harder or smarter? British Journal of Sports Medicine. 50, 273-280
International Tennis Performance Association (2012). Certified Tennis Performance Specialist workbook and study guide. International Tennis Performance Association.
Khmais, H.J.,Roche, A.F. (1995). Predicting adult stature without using skeletal age: The Khamis Roche Approach. Pediatrics, 94 (4), 504-507.
Lloyd, R., Cronin, J.B., Faigenbaum, A.D., Haff G., Howard, R., Kramer., W., …Oliver, J.L.(2016). National Strength and Conditioning Association Position Statement on long-term athletic development. Journal of Strength and Conditioning Research, 30 (6), 1491-1508.
Jayanthi, N., Feller, E., & Smith, A. (2013). Junior competitive tennis: ideal tournament and training recommendations. Journal of Medicine and Science in Tennis. 18 (2), 30-35.
Jayanthi, N. & Tzakis, E. (2016). Return to play tennis on-court stroke modification following injury in junior competitive tennis players. Journal of Medicine and Science in Tennis. 21 (1), 28-35.
Kovacs, M. & Ellenbecker, T. (2011). An 8-Stage Model for Evaluating the Tennis Serve Implications for Performance Enhancement and Injury Prevention. Sports Health. 3 (6), 504-513.
Malina, R.M., Dompier, T.L., Powell, J.W., & Moore, M.T. (2007). Validation of a non-invasive maturity estimate relative to skeletal age in youth football players. Clinical Journal of Sport Medicine. 17 (5), 362-368.
Mirwald, R.L., Baxter Jones, A.D., Bailey, D., Beunen, G.P. (2002). An assessment of maturity from anthropometric measurements. Medicine and Science in Sport and Exercise, 34 (4), 689-694.  
Ochi, S.,Kovacs, M. (2016). Periodization and recovery in the young tennis athlete. In A.C.Colvin and J.N.Gladstone (Eds.), The young tennis player, injury prevention and treatment (pp.87-104). Springer.
Saw, A.E., Main, L.C., & Gastin, P.B. (2015). Monitoring the athlete training response: subjective self-reported measures trump commonly used objective measures: a systematic review. British Journal of Sports Medicine. 50, 281-291.
Sluis, A., Elferink-Gemser, M.T., Brink, M.S., Visscher, C. (2015). Important ofpeak height velocity timing in terms of injuries in talented soccer players. International Journal of Sports Medicine, 36 (04), 327-332.
Strendjord, S.E. and Rome, E.S. (2016). Growth and development in the young athlete. In A.C.Colvin and J.N.Gladstone (Eds.), The young tennis player, injury prevention and treatment (pp.87-104). Springer.
University of Saskatchewan. (2017). Prediction of Age of Peak Height Velocity. Retrieved from http://kinesiology.usask.ca/growthutility/phv_ui.php.
University of Washington Radiology Department. (2017). Prediction of Age of Peak Height Velocity. Retrieved from http://uwmsk.org/stature.html.

By Jonny Fraser, Owner of Science in Tennis, Strength and Conditioning Coach Claudio Pistolesi Enterprise,
CTPS, MTPS

Long Term Athletic Development (LTAD) refers to the athletic progression of young people improving health and wellbeing, physical performance, reducing the risk of injury and enhancing psychosocial development. Without doubt it is very multifactorial, non-linear process and requires coaches and sport scientists to be adaptable and understand how children’s anatomy and physiology varies (Lloyd et al., 2016). Recent evidence has been published with updated position statements from various organisations and highly respected practitioners about LTAD (Faigenbaum, 2017, Ford et al., 2013, Lloyd et al., 2016). The aim of this blog is to consider the challenges many coaches face within tennis centres such as coaching large groups of young people across various chronological, biological and training ages and how can they practically apply this evidence every day and longer term in their coaching programs.

Consideration one: motor skills and strength are the foundations.

Figure 1 U16 Mesocycle for Training to Compete Phase U16 Group   High, Medium, Low

The development of technical skills in tennis requires the ability to produce and reduce force through a synchronised neuromuscular coordinated action. Without having this base of solid motor skills and strength an increased risk of injury may occur alongside a negative association with tennis.

The implementation of a strength and conditioning program or ‘multiskills (SCM)’ programs can provide a long-term solution to tennis centre programs.  Sessions can vary based on ages from 30 minutes before or after the tennis session for younger players combining fundamental movement skills within a game based approach, to more structured and individualised sessions, multiple times a week as part of tennis squads or stand-alone sessions. These sessions will have greater emphasis on tennis specific training as players get older  (Figure 1). Alternative activities within a structured program also provides diversity, continually helping develop fundamental movements skills and may reduce the risk of injury and provide ‘time out’ from the challenges associated with larger volumes of tennis training.  Examples may include yoga sessions, rock climbing and/or team based games within the program (Figure 1).

For this to be effective it requires long term planning from a range of parties including the tennis manager, coaches and sport science support team involved. Coaches must also have a philosophy or ‘vision’ that can be communicated to the parents and players. It is essential that parents of players are educated about the benefits of SCM. This can be done via the use of traditional methods such as information or parents evening, or using screencasts and webinars as alternative options (Figure 2).

Within everyday setting the use of warm ups provide a very effective time to deliver SCM. This may involve 10-15 minutes of fundamental motor skills such as hopping, jumping and landing to working on tennis specific movements. The dynamic warm up also allows an effective time to develop lunging, pushing, pulling, bracing, rotating or hinging exercises, the corner stone of strength training. Effective progressions and regressions can be used to challenge players of all ages. Furthermore, providing players with ‘home workout’ or ‘on the road’ training cards can also provide a simple, yet effective method to integrate SCM at an everyday level across a large number of players. This can be set as ‘homework’ or as the ‘coaches special’ (see consideration four ‘embrace the teaching’ in the following part of this blog).

Figure 2: Screencasts can be an alternative option to provide parents with information.

Consideration two: Tennis Centres can be used as hubs to promote lifelong health and wellbeing.

The NSCA Position Statement (2016) below explains health and wellbeing is one of the ten pillars of LTAD:
“Health and Wellbeing of the Child Should Always Be the Central Tenet of Long Term Athletic Development Programs”
Tennis centres and coaches have the important role to understand the benefits that tennis has on the health and wellbeing, the holistic elements that surround that such as cognitive, affective and lifestyle elements by providing both an environment for psychological and physical development.

Process orientated goal setting with players can be one way in which to do this both short, medium and long term (Lloyd et al., 2016). For example, at the start of the term, players who attend regular coaching but play a lower volume of tennis can set simple process goals which can be written down and reviewed at the end of each term. This may be just one technical, tactical, mental or physical goal. Where, more detailed goals may be set with players who have higher training volumes focusing on developing several areas, alongside setting outcome goals.

The language in which coach’s use is also very important. The aim is to use language which creates an environment to promote a growth mindset and embrace challenging scenarios. This may be praising the strategy that students have come up after you have observed a technical area to develop or to reinforce the positive of being unable to perform a task, for example:“I like the way you worked out how to get more top spin on the ball from that position, what did you do?”
or “Great work keeping your shoulders back during that deadlift, how did you work out to do that?”or
“I really like how you maintained focus throughout today’s session and really worked on the theme of our session”or
“You can’t quite manage that power clean technique yet, let’s just work on that start position and it will come.” Within longer term planning setting out sessions where the players are the ‘teachers and coaches” can be one way to develop the feelings of autonomy to facilitate learning. This could be a week where players are given a challenge such as setting up an injury reduction circuit or planning the week’s lessons linked to the current theme in the mesocycle. This will help create a motivational climate which players can embrace.

Longer term planning may involve the organisation of sport science workshops such as nutritional and mental skills workshops being incorporated within programs to support player’s development. This can either be done through workshop or online mediums and may be scheduled monthly (Figure 1). Workshops should first promote the health and wellbeing of young people such as how the mental skills or nutritional information will help players throughout their lives (such as what is healthy eating) to more performance related strategies for players competing regularly in the sport. Some workshops can be open to all players and parents, where others may be more tailor made to different target groups. As mentioned above this requires well-structured macro and mesocycles with tennis managers, coaches and the sport science team supporting the tennis centre.

Part one of this blog was to consider the evidence of LTAD and how this can be implemented within tennis centres with focus on motor skill and strength development, alongside the vision that tennis centres can be used as hubs to promote health and wellbeing to young people every day and longer term level. Part two will focus on other considerations including “embracing the teaching “and “monitoring/assessment tools for young players.
 
 
References
Faigenbaum, A.(2017). Resistance exercise of youth: survival of the strongest. Paediatric Exercise Science, 29(1), 14-18.
Ford, P., De Ste Croxi, M., Lloyd, R., Meyers, R., Moosavi, M., Oliver, J., Till, C. and Williams, C. (2016).The long term athlete development model: physiological evidence and application. Journal of Sport Sciences, 29(4), 389-402.
Lloyd, R., Cronin, J., Faigenbaum, A.D., Haff, G., Gregory, H., Kraemer, W.J., Micheli, J.l., …Oliver, J. (2016). National Strength and Conditioning Association position statement on long-term athletic development. Journal of Strength and Conditioning Research, 30 (6), 1491-1509.

What Exactly are you Training?

Maybe it’s me but it seems like YouTube and Facebook are packed with more and more fitness videos that are proving to be more circus oriented than quality driven. I truly feel sorry for parents, athletes and coaches who don’t have the background to properly analyze what they are watching. Just because someone posts a video that they say works a particular physical aspect or because they are skillful at producing a video does not mean it is of quality. I recently came across a video that had a young athlete bouncing and jumping over hurdles in order (I think) to train for better agility. Now for a parent or sport coach, this “may” have looked interesting and perhaps functional. Let’s say that the drill was providing some type of element for better movement, but the way this young athlete was performing it was without a doubt completely wrong. Legs flopping to the side when going over the hurdles, improper landing technique and a lack of coordination because this athlete was not prepared for this type bombardment.

So next time you come across a video you find interesting and may want to implement into your fitness training, I have a very easy way to evaluate it for you. Ask yourself why? Why would you use it? What outcome will it provide for you whether you are a coach, parent or athlete? Does it fit into your scheme of what you are presently coaching?
Exercise need not be complicated. The complexity comes from the simplicity. I once read that simplicity + consistency = success (thank you Brian Grasso). I found this to be true of most things, not only within the training world. Create a stable and strong foundation for the athlete and then proceed to construct a building that can not only perform at a high level but also withstand the constant rigor of competition and training. Always think quality over quantity when training. Get great at the simple things and the rest will follow. You may not look like to coolest person in the gym but I’m pretty sure that when competing, your solid foundation and training will take you a long way.
by Dean Hollingworth CSCS, CTPS, MTPS
Director of Fitness and High Performance
Club Côte-de-Liesse, Montreal, QC
[email protected]

By Jonny Fraser, MTPS, Msc, CSCS
Owner Science in Tennis (www.scienceintennis.com)

Everyone has a story why they began playing tennis. Often it is a family member or friend having a decisive influence. Otherwise living close to a tennis club or being inspired by watching the game on television may have led to picking up a racket. No matter the reason, tennis offers lifelong participation and the opportunity for continued development through a ‘journey’ of discovery. Sometimes this journey seems easy; groundstrokes and strategies are executed with efficiency whilst other days no matter the effort nothing seems to work effectively. This mirrors life, some days everything falls into place, we seem to achieve all we set out to do feeling energised and positive. Others days are a challenge: we come across barriers, frustrations feeling exhausted and drained. This ‘trauma’ tennis links to life are unparalleled. It is important the journey is embraced but also recognised how it helps us develop as people.  

Bailey (2006) discusses five developmental area sport offers. These include physical, cognitive, affective, social and lifestyle components. These improvements in mind, body and social wellbeing are well established in the literature for tennis players (Pluim, 2007, Groppel and Di Nubile, 2009). The most discussed element is the benefits tennis has on quality of life and physical health (Pluim et al., 2007). Increased aerobic capacity, improved bone health and body composition amongst other enhanced health benefits are well documented (Pluim et al., 2007). Other considerations can be made toward improved coordination, balance, strength and agility (Groppel and Di Nubile, 2009).

The cognitive element focuses on developing problem solving, decision making, enhancing productivity and increased mental alertness (Bailey, 2006, Groppel and Di Nubile, 2009). Tennis is a game of ‘chaos’ with tactical intention changing regularly and technical inaccuracies needing to be addressed often without coach support. We must be able to problem solve and adapt. Tennis teaches us discipline, be that on a technical element, using a game plan or following a conditioning program. It shows us we must take responsibility for our actions and that we’re in full control of what we chose to do. Tennis challenges us to develop a growth mindset. We need to embrace challenges, deal with setbacks positively whilst striving to improve ourselves each day. If we fail to do this in tennis, like in life we may not achieve our full potential on and off court.
Evidence suggests improved self-esteem, confidence, reduced stress, anxiety and depression are positive influences from participating in tennis (Groppel and Di Nubile, 2009, Yazici et al. 2016). This affective development with perceptions of competency, ability to achieve, self-worth and psychological well being have far reaching benefits (Bailey, 2006). Furthermore, it has been well documented that sport and exercise releases endorphins improving mental wellbeing (Harber and Sutton, 1984).

The last two areas interrelate to the above developments. From a social aspect tennis can lead to new friendships due to the interactive element of the sport and club environment. Players compete ungoverned developing fairness and respect for each other alongside taking personal responsibility. Tennis teaches you skills such as perseverance, commitment, good habits and behaviours that can last a life time from living a healthier lifestyle to be able to cope in challenging situations.
That is why tennis is a sport which provide players opportunities to constantly develop helping them both on and off court.
Take Home Messages:

• Coaches must promote the long-term benefits of tennis to significant others linked to the physical, cognitive, affective, social and lifestyle development areas. This can be used to support a growth mindset of players.
• As a player embracing the challenges tennis offers provides a ‘journey’ of discovery and you can use these skills in a vast number of scenarios such as in school, at work and social situations.
• Tennis is a sport no matter your age or ability which requires you to pursue improvement and this development benefits you in wide ranging ways through improved health and well being.
  

 
References
Bailey, R. (2006). Physical education and sport in our schools: a review of benefits and outcomes. Journal of School Health, 76 (8), 397-401.
Groppel, J., & Di Nubile, N. (2009). Tennis for the health of it! The Physician and Sports Medicine, 37 (2), 40-50.
Harber, V.J., & Sutton, J.R. (1984). Endorphins and exercise. Sports Medicine, 1 (2), 154-171.
Pluim, B.M., Stall, J.B., Marks, B.L., Miller, S., & Miley, D. (2007). Health benefits of tennis. British Journal of Sports Medicine, 41, 760-768.
Yazici, A.B., Gul, M.,Yazici, E & Gul, G.K. (2016). Tennis enhances wellbeing in university students. Mental Illness, 8, 21-25.

Guest blog post by Brian Nathanson, DC, CTPS
Article link posted below - please follow him for more great articles!

This is the question I hear many times when I tell my rotator cuff and tennis elbow clients they have Tennis Hip Syndrome. Over the years I have had the pleasure of working with many tennis professionals and passionate amateurs. During this time I have noticed a very common pattern yet to be named. For lack of a better term I have decided to call it Tennis Hip Syndrome.

As someone who looks at an athlete’s biomechanics, I became frustrated with patients returning with continuous reports of rotator cuff pain and the classic tennis elbow. They would leave my office feeling good and within a few short weeks, they would return. Upon examination of most of these athletes most had limited trunk mobility and more importantly they had difficulty pivoting on their hips. In technical terms it is called restricted internal and external hip rotation. These people can be great athletes, but they move best in what I call a linear motion. They can run, cycle, jump with ease, but ask them to twist like a corkscrew and they will have difficulty.
A tennis player needs to be able to go not only forward, but in every direction. If a player doesn’t have good hip motion, it will cause more stress on the low back, rotator cuff and eventually the elbow. This is caused by their bodies trying to fulfill the desired motion without the necessary hip and pelvic motion.
Think of what hurts a tennis player. Their low back, front of the shoulder and elbow. It plagues them in all aspects of their game. The shoulder will ache during serves and overheads, the elbow will be painful during backhands, at the net. The player needs to turn, but the body won’t do it, the hips don’t spin, the ribs are tight and they will improperly use their shoulders, elbows and wrists.
How does this happen?A study was actually done with Major League Baseball outfielders, looking at the connection between rotator cuff pain and restricted hip motion. The throw from the outfield is similar to a tennis overhead. If you are right handed, you push off the right leg for power, the right hip comes forward and rotates to the left. The player then lands of the left leg, pivots and comes to a stop. It is all that momentum and force on the left hip, the “non-dominate” one that acts as a brake. It gets stronger, more muscular and tighter. As this progresses the risk for injury becomes greater.
How do I know I have Tennis Hip?There is a simple test. Sit on a high bench, chair or counter top where your legs can swing side to side freely and then allow them to do just that. As your feet dangle to the floor, consider the position of your shins as if they were on a clock face, where the middle of your foot is at 6, now, without leaning one way or the other try bringing each foot around the face of the clock, up towards 8 and up towards 4. Most of us will not be able to reach those numbers and will maybe get to 5:30 and 6:30. If you fall into these clock ranges, you are at risk of developing a tennis related shoulder problem because of decreased hip mobility
How to Treat and Correct it.Treatment options are simple. But like any other physical regimen, you must be motivated and diligent. Self care includes many different motions to release and stretch the hip and groin regions. Stretches should be performed on the gluteal regions, upper inner thigh, hamstrings and lower leg. Besides stretching players need to aggressively massage the muscles using something like a foam roller or other tools, and instruments that actually break down the large, overdeveloped stiff tissues. Clinicians (Chiropractors, Orthopedists, Physical Therapists) can provide treatment that can sometimes provide the jump start for this program. These clinicians will perform a release of the tissues with either their hands, elbow massages or instrument assisted myofascial release . Due the substantially muscular nature of this region of the body, most participants will require more than one treatment. Once the therapy is complete, it is up to the player to continue the stretching and rehabilitative protocols established by their physician or therapist. As with any ongoing athletic endeavor, being professionally treated on a timely basis can help keep this injury from frequently reoccurring.


https://medium.com/@briankn58/tennis-hip-syndrome-34a2edf1f804#.r05ebn6vb