Tennis elbow gets worse when you repeatedly grip, twist, or extend your wrist against resistance, especially if you don’t modify the activities that caused it in the first place. The condition isn’t actually an inflammation problem. It’s a degenerative process in the tendon that anchors your forearm muscles to the bony bump on the outside of your elbow. Every time you stress that damaged tissue without adequate recovery, you deepen the cycle of micro-tearing and disorganized healing that keeps the pain going.
Why the Tendon Doesn’t Just “Heal”
The specific tendon involved in tennis elbow connects to a muscle called the extensor carpi radialis brevis, which runs along the back of your forearm and controls wrist extension. When this tendon is overloaded repeatedly, the tissue doesn’t respond the way a fresh injury would. Instead of mounting a normal inflammatory response with immune cells rushing in to repair the damage, the tendon develops disorganized collagen fibers, an overgrowth of blood vessels, and small tears within the tissue itself.
This matters because it means the tendon is structurally weakened, not just irritated. Ultrasound imaging of affected elbows often shows calcifications, internal tears, and thickened, irregular tendon tissue. Anything that loads this compromised tendon, whether it’s a single forceful grip or hundreds of small repetitions throughout the day, pushes it further from recovery.
Everyday Movements That Add Up
The most common aggravators aren’t dramatic. They’re the small, repetitive motions you do dozens of times a day without thinking: turning a doorknob, opening a jar, shaking hands, carrying a grocery bag with your palm facing down. Any motion that requires you to grip something while your wrist is extended puts load directly on the damaged tendon. Wringing out a towel, using a screwdriver, lifting a frying pan, even pouring from a full kettle can flare symptoms.
What makes these movements particularly damaging is that the tendon is under “eccentric” load during many of them, meaning it’s trying to control a force while being stretched. Think of slowly lowering a heavy mug to a table. Your forearm muscles are lengthening under tension, and that lengthening force is exactly what stresses the injured attachment point most.
Computer Work and Desk Ergonomics
If your tennis elbow developed or worsened after long hours at a computer, your workstation setup is likely part of the problem. A mouse that sits too high or too far away forces you to repeatedly overextend your forearm to reach it. A mouse that’s too small keeps your finger, hand, and wrist muscles locked in a tense, contracted position for hours at a time. Both scenarios create sustained low-grade strain on the same tendon.
A few specific mistakes make things worse. Raising the back of your keyboard increases wrist strain rather than reducing it. Keeping your wrists bent upward or downward instead of straight puts the forearm extensors under constant tension. Hunching your shoulders up toward your ears shifts load into your forearms. A cluttered desk forces you to reach and extend more often than necessary. If your forearms sit too high relative to your keyboard, the angle compounds the problem with every keystroke.
The fix is straightforward: your wrists should be straight and neutral, your mouse close enough that you don’t have to reach for it, and your chair height adjusted so your forearms rest naturally at keyboard level.
Sports Technique Errors
Among tennis players, technique problems are a bigger risk factor than playing volume. Research comparing players with and without tennis elbow found that affected players had significantly greater activity in their wrist extensor muscles during ball impact and the early follow-through phase. This extra muscle firing was linked to specific technical faults: a “leading elbow,” an open racquet face at impact, wrist extension during the stroke, and hitting the ball on the lower half of the strings.
The backhand stroke is the primary culprit, and the difference between experienced and novice players is telling. Experienced players strike the backhand with their wrist extended about 23 degrees from neutral, and it moves further into extension at impact. Their forearm muscles fire hardest after the ball leaves the strings, which is a normal, controlled effort. Novice players do the opposite: they hit the ball with the wrist flexed about 13 degrees, and it continues flexing through impact. Their forearm extensors fire at the same high level despite the wrist moving in the wrong direction. This means novice players are eccentrically loading their wrist extensors throughout the entire stroke, precisely the type of force that damages the tendon.
Interestingly, racquet grip size, often cited as a risk factor, may not matter as much as people think. A study found that changing grip size by a quarter inch in either direction didn’t significantly alter forearm muscle activity. Technique correction, particularly learning to hit the ball in front of the body with the wrist and elbow extended, is more important than equipment changes.
Exercising Too Hard, Too Soon
Rehab exercises are one of the most effective treatments for tennis elbow, but pushing them too aggressively can make the condition worse. The American Academy of Orthopaedic Surgeons recommends starting with only the lowering (eccentric) phase of wrist exercises, using a very light weight of one to three pounds, to help resolve acute pain before progressing to the full range of motion.
The progression threshold is specific: you should be able to perform 30 repetitions on two consecutive days without increasing pain before adding even one pound of weight. Skipping ahead, using heavy resistance bands, or doing high-repetition gripping exercises before the tendon can tolerate them reloads damaged tissue faster than it can adapt. Pain during an exercise is a clear signal to back off, though some mild discomfort is expected.
Aggressive stretching of the forearm extensors in the early stages carries similar risks. Forcefully pulling the wrist into flexion to “stretch out” the sore tendon can stress the already-compromised tissue at its attachment point. Gentle, pain-free stretching is useful, but there’s a meaningful difference between easing into a stretch and yanking on an injured tendon.
Smoking and Tendon Health
Tobacco use appears to worsen outcomes for tendon injuries across the body, and tennis elbow is no exception. The damaged tendon in lateral epicondylitis already has poorly organized collagen and abnormal blood vessel growth. Nicotine constricts blood vessels and reduces oxygen delivery to tissues, which is particularly harmful for tendons that already have limited blood supply. Research on rotator cuff repairs has shown that smokers have worse surgical outcomes than nonsmokers, and the same biological mechanism applies to the forearm tendons involved in tennis elbow. If you smoke and have persistent tennis elbow, the habit is likely slowing your recovery.
Ignoring It and Pushing Through
Perhaps the single biggest factor that makes tennis elbow worse is continuing the activity that caused it without modification. Because the condition is degenerative rather than inflammatory, it doesn’t resolve on its own if you just wait for “the swelling to go down.” There is no meaningful swelling. The tissue is structurally breaking down, and every repetition of the aggravating movement adds to the damage.
This doesn’t mean you need to stop using your arm entirely. Complete rest can actually weaken the tendon further by depriving it of the controlled loading it needs to remodel. The key is reducing the specific movements that provoke pain, using tools like counterforce braces to offload the tendon attachment, modifying your grip technique, and gradually introducing controlled strengthening exercises as pain allows. The people who recover fastest are the ones who identify their aggravators early, reduce exposure to them, and build the tendon’s tolerance back up methodically rather than cycling between ignoring the pain and resting completely.