Mark was 32 the first time his elbow stopped him mid-swing. There was no fall and no collision. He felt a dull ache on the outside of his arm, and it had been building for weeks. He ignored it through three tournaments. Then one backhand made him drop the racket. He assumed the pain would pass on its own. Six months later, he was still changing his grip to avoid it.

His story is common enough that sports medicine gave it a name: tennis elbow. Tennis has a reputation as a gentle, low-contact sport. For the tendons and joints that absorb thousands of swings every season, that reputation holds up less well than it sounds. Recent systematic reviews now show where the physical cost of the sport really lands and which strokes create the most strain. They also show which specific changes reduce the risk, and that part surprised me more than the injury numbers.

How common are tennis injuries, really?

Catastrophic injuries are rare in tennis. Overuse injuries are a different story. A 2025 systematic review published in the journal Sports pooled 37 studies on adolescent and adult high-performance players. Seasonal injury prevalence reached 46 to 54 percent in juniors and 30 to 54 percent in professionals. Put simply, about one serious player in two gets hurt badly enough to lose training or match time within a single season.

Injury incidence varied a lot between studies. Juniors had 2.1 to 3.5 injuries per 1,000 hours of play. Adults went from 1.25 up to 56.6 injuries per 1,000 hours. That wide spread reflects differences in playing intensity, court surface and competition level.

What counts as an overuse injury? It is damage that builds slowly from repetition, not from one event. A tendon, a joint or a bone absorbs the same stress so often that repair falls behind. Pain usually starts mild, appears after play and fades by the next day. Over the following weeks, it shows up earlier and lasts longer. That slow start is exactly why so many players keep going.

Where injuries land in high-performance players, according to the 2025 review:

1. Lower limb: 48 to 56 percent of all injuries, the largest share by far.
2. Lumbar spine (lower back): 12 to 39 percent, depending on the study.
3. Shoulder: overuse syndromes close behind the lower back.

Junior players follow a pattern of their own. Orthopedic literature cites an estimate that about 12 percent of elite juniors aged 11 to 14 develop an overuse injury every single week during intensive training blocks. Their bodies are still growing, and they absorb a large amount of repeated load. A separate review on elite juniors searched five databases and screened more than 4,000 results. Only five studies met strict criteria for identifying true risk factors. That gap worries me, because young players are the group that most needs good data. I cover the wider picture in my article on injury prevention programs in youth sports.

A 2025 comparative review of padel, tennis and squash adds useful context. Tennis players injured the lower back, ankle and knee more often than players of the other two sports. Padel players injured the shoulder, ankle and knee. Squash players concentrated their injuries in the ankle and knee. The differences come from how each sport loads the body. Tennis combines long rallies, wide lateral movement and an overhead serve that padel and squash do not ask for in the same way.

Both reviews agree on one thing. Tennis injuries rarely come from a single bad step or a freak accident. They build gradually, stroke after stroke, thousands of times per season.

The serve: the most demanding stroke in tennis

If tennis injuries share one thread, it is the serve. A review published in the Journal of the American Academy of Orthopaedic Surgeons reports that the serve makes up 45 to 60 percent of all strokes in a professional service game. That is about 43 serves per set. It is also the most violent motion in the sport. Force starts in the legs and travels through the trunk. It ends with the arm braking at very high speed, and the shoulder and elbow absorb that braking.

A 2025 meta-analysis published in Advances in Rehabilitation Science and Practice studied this stroke in detail. The researchers reviewed 29 studies and found 130 distinct risk factors linked to serve injuries. Of those, 36 had an effect large enough to be statistically meaningful. The strongest predictors were dominant shoulder rotation strength, internal rotation range of motion, weekly tennis volume, age, body mass and height.

Internal rotation deserves a closer look. It is the ability to turn the arm inward at the shoulder, and years of serving often reduce it. When it drops, the shoulder shifts stress onto the rotator cuff and the labrum, the rim of cartilage around the socket. A related problem is scapular dyskinesis, which means the shoulder blade moves abnormally during overhead motion. Earlier research linked it to a 43 percent higher risk of future shoulder pain in overhead athletes. That held even for players with no symptoms at the time of testing.

Here is a practical example. Picture two club players with identical serves. The first plays three relaxed sessions a week, every week. The second plays one session a week for a month, then enters two tournament weekends in a row. Their technique is the same. Their shoulders are not facing the same risk, because the second player loaded the joint far faster than it could adapt.

A second example comes from inside a single match. A player who serves well in the first set often starts “arming” the ball in the third. The legs tire, so the arm does more of the work. The serve looks almost the same from the stands, but the shoulder is now carrying load the legs used to carry. Weekly volume and fatigue matter on their own, and the pace at which volume grows turned out to matter even more.

Tennis elbow: the injury that gave the sport its name

Lateral epicondylitis is the medical name for tennis elbow. A 2023 meta-analysis of its risk factors found that it affects about 1 percent of adults overall, with a peak between ages 35 and 55. Among tennis players, lifetime incidence is estimated at 40 to 50 percent.

The mechanism is simple once you picture it. The wrist extensor muscles of the forearm attach to a bony bump on the outer elbow, the lateral epicondyle, through a single tendon. Every backhand and every off-center forehand sends force through that tendon. Repeated thousands of times, small amounts of damage pile up faster than the tendon can repair them. Researchers now describe this as a degenerative process rather than simple inflammation.

The early signs are easy to miss. Pain sits on the outer side of the elbow and often spreads into the forearm. It gets worse when you grip something, lift a full cup of coffee or turn a door handle. Many players first notice it off court, at work or at home, and only later during a match.

A systematic review on upper-limb injury risk factors in tennis, published in the International Journal of Environmental Research and Public Health, found that upper-limb injuries make up 28 percent of all injuries in adult men and 23 percent in adult women. The shoulder was the most frequently injured site in that group. The authors listed several contributing factors, including long exposure to tennis, scapular dyskinesis, muscle fatigue, skill level and stroke technique. They also stressed that tennis injuries rarely have one isolated cause.

Three practical factors change the load on the elbow directly:

1. Grip size. A grip that is too small forces the forearm muscles to squeeze harder to control the racket. That raises tendon strain on every stroke.
2. String tension. Higher tension sends more shock into the arm on off-center hits instead of letting the racket absorb it.
3. Backhand technique. A one-handed backhand with late timing or a leading elbow loads the extensor tendon far more than a well-timed two-handed stroke.

None of these factors acts alone. A player with a small grip, tight strings and an inconsistent backhand collects risk from all three at once. That is why equipment checks appear so often in prevention research.

Treatment follows the same logic as prevention. Across the treatment literature, exercise programs based on eccentric loading of the wrist extensors do better over the long term than rest or bracing alone. Eccentric loading means the muscle works while it lengthens, as when you lower a weight slowly. For stubborn cases, injection therapies are also studied. I review that evidence in a separate article on platelet-rich plasma for sports injuries and tendon damage.

Shoulder, lower back and the workload trap

Tennis elbow gets most of the public attention. The epidemiological data, however, show that the shoulder and the lower limbs carry a heavier overall burden. In the 2025 high-performance review, lower-limb injuries made up roughly half of all injuries in both juniors and adults.

Shoulder overuse works differently from a sudden injury. The serve and overhead strokes put the shoulder in extreme positions again and again. The tendons and stabilizing muscles around the joint collect what researchers call cumulative microtrauma: tiny amounts of damage that add up. A clinical review on shoulder evaluation in tennis players found that a long match measurably reduces internal rotation afterward. One long match produces a temporary change. Repeated across a season, the same change can become a lasting problem.

The strongest external predictor in the 2025 review was not total playing volume. It was how quickly that volume increased.

Researchers measured this with the acute-to-chronic workload ratio. It compares a player’s most recent week of training with the average of the previous four weeks. When the ratio climbed above 1.3 in juniors, or above 1.5 in adults, injury risk rose substantially. In plain terms, a player who trains steadily at high volume is safer than one who suddenly doubles their hours after a quiet stretch. This held even when the total hours ended up similar.

Here is how the numbers work in practice. A junior averages 10 hours a week over a month. If the next week reaches 13 hours, the ratio hits 1.3, the point where junior risk started to climb. An adult averaging 8 hours a week who suddenly plays 12 hours reaches 1.5. Neither jump looks dramatic on paper. The data say both are enough to matter.

Internal factors add to this external risk. The 2025 review found three of them again and again:

• reduced internal rotation of the shoulder, the same limitation seen in the serve research;
• scapular dyskinesis, the abnormal shoulder blade movement described earlier;
• poor core stability, meaning weak control of the trunk muscles.

The core matters more than most players think. The trunk transfers force from the legs to the arm during the serve. When trunk control is weak, the shoulder and the lower back pick up the slack. The lower back link is familiar from outside sport too, as I explain in my article on muscle control and chronic low back pain.

Fatigue plays a documented role as well. A systematic review and meta-analysis of 18 trials involving 318 tennis players started from 642 records across three databases. In the included trials, fatigue changed blood lactate and heart rate. It reduced explosive strength and speed. It also lowered stroke velocity and accuracy. A tired player does not simply play worse. Their movement changes, often toward patterns that put more stress on the shoulder and the legs. This happens in third sets, long rallies and back-to-back tournament days, exactly when accumulated load has already raised the risk.

Court surface also plays a part, although its effect varies more than workload does. A systematic review on tennis surfaces found that injury incidence differs by court type. Clay lets players slide into wide balls, which can lower peak impact on the knee and ankle compared with the sudden stops of hard courts. Clay, in turn, puts its own demands on the hip and groin. Grass changes footing and reaction time enough to shift the pattern again. No surface comes out as safer overall. The review’s authors advised judging surface together with training load, not as a risk factor on its own.

What actually prevents tennis injuries

The best news in this research is about prevention. The 2025 high-performance review identified three strategies with measured results. They came from physiotherapy-led studies included in the analysis.

1. Controlling external load. Structured four-week ramp-up periods let training volume grow gradually instead of jumping. They reduced injury incidence by up to 21 percent. This targets the workload ratio problem directly. Players who build volume in planned steps avoid the sharp weekly spikes that the data flag as the strongest single risk factor.

2. Kinetic-chain conditioning. The kinetic chain is the sequence of body segments that pass force from the ground to the racket. Programs that combined core stability work with eccentric rotator cuff exercises cut overuse injuries by 26 percent. They also preserved shoulder mobility across a competitive season. Eccentric work suits tendons well. It improves the capacity of the tissue to absorb the repeated loading that causes tennis elbow and rotator cuff problems in the first place.

3. Technique and equipment adjustments. Matching grip size to hand size and playing style cut rates of lateral epicondylalgia, the broader term for elbow tendon pain, roughly in half. Adjusting serve timing also helped. Better coordination between leg drive, trunk rotation and arm acceleration reduced the measured twisting load on the shoulder.

None of this needs expensive equipment or a professional staff. Here is what it looks like in real life:

• A recreational player writes down weekly court hours in a phone note and avoids sudden jumps.
• A club coach adds ten minutes of core and rotator cuff exercises to the usual warm-up.
• A racket technician checks grip size during a routine restringing.

Tracking load does not have to be sophisticated. Some professional teams now use wearable sensors and prediction models to flag risky weeks before injuries happen, a topic I explored in my article on machine learning that predicts sports injuries. For a club player, a simple training diary covers most of the same ground.

These small, specific steps work better than vague advice like “play smarter” or “listen to your body.” They target the exact mechanisms the injury data point to: workload spikes, lost shoulder rotation and tendon overload.

The evidence still has limits, and I think they are worth stating. The 2025 review graded its evidence with the GRADE system, a standard method for rating how much confidence a result deserves. It found large differences between the underlying studies in how they defined injuries, rated severity and measured outcomes. Because of this, the authors could not combine all the data into one formal meta-analysis. The individual findings on workload, conditioning and equipment still stand, since each came from studies built to test that specific intervention. The field does need more standardized reporting, a point the junior review made when only five of more than 4,000 screened studies qualified.

Quick reference for players and coaches

• Increase weekly training hours gradually and avoid jumps of more than 30 to 50 percent from one week to the next.
• Add eccentric rotator cuff and core stability exercises to your regular warm-up.
• Have grip size and string tension checked against your hand size and playing style.
• Check shoulder internal rotation from time to time, since a measurable loss often comes before pain.
• Treat elbow soreness that lasts more than a few days as a signal to change technique or equipment.

What Mark’s elbow teaches every player

The pattern in this research is consistent. Tennis injuries come mostly from overuse, not accidents. The serve drives much of the shoulder and elbow load. Tennis elbow affects 40 to 50 percent of players over a playing lifetime. The single strongest predictor of injury is a sudden rise in training load, not the total number of hours.

The same data point to fixes that any player can apply. A four-week ramp-up cut injuries by up to 21 percent. Core and rotator cuff conditioning cut overuse injuries by 26 percent. A correctly sized grip cut elbow pain rates roughly in half. Players between 35 and 55 deserve extra attention, since that is the age band where tennis elbow peaks in the general population.

Mark’s elbow recovered. It took a larger grip, eccentric forearm exercises and six weeks of gradual return instead of a jump straight back into tournaments. His case was not unusual. He followed the exact path the research describes: gradual overload, a preventable mechanism and a recovery built on the same principles that could have prevented the injury.

If you play regularly, start with the simplest step this week. Write down your hours on court. A jump of more than 30 to 50 percent from one week to the next is the number to watch.

References

1. Amor-Salamanca MS, Rodriguez-Gonzalez EM, Rossello D, de Lluc-Bauza M, Hermosilla-Perona F, Martin-Castellanos A, Herrera-Peco I. Risk factors and prevention of musculoskeletal injuries in adolescent and adult high-performance tennis players: a systematic review. Sports. 2025;13(10):336.
2. Bradley J, Langdown BL, Bowmaker D, Kerr S. Injury risk factors of the tennis serve: a systematic review and meta-analysis. Adv Rehabil Sci Pract. 2025;14.
3. Kekelekis A, Nikolaidis PT, Moore IS, Rosemann T, Knechtle B. Risk factors for upper limb injury in tennis players: a systematic review. Int J Environ Res Public Health. 2020;17(8):2744.
4. Dines JS, Bedi A, Williams PN, et al. Tennis injuries: epidemiology, pathophysiology, and treatment. J Am Acad Orthop Surg. 2015;23(3):181-89.