Tennis elbow and your racquet: what gear can and cannot do
Updated: 3 hours ago
Tennis elbow. That is the phrase you typed; it is not the one used in the workshop, where we say lateral epicondylitis, or more cautiously a tendinopathy of the extensor tendons. The name matters little. The first thing to say is the same in both languages: a racquet is not a treatment. If your elbow hurts, a doctor or a physiotherapist comes before any change of equipment, and nothing below replaces that advice.
What equipment can do is narrower, and real. It can stop feeding the problem. This article is only about that: what the racquet, the string and the tension send back to the arm, what can be measured, and in what order things should be changed.
What the racquet will not do
It does not heal. It replaces neither rest, nor strengthening, nor work on the stroke. We sell nothing that promises recovery, and a product that promised you one should make you suspicious.
Nor does it compensate for a technique that loads the elbow. A one-handed backhand taken late, a serve hit with a locked arm, a wet ball struck cold: no measured value fixes that. It is your coach's job, not a frame's.
What it does decide is the quantity and the nature of what travels from the string bed to the hand. And that part can be measured.
The string, more decisive than the frame
This is the strongest lever, and by far the cheapest. Between a soft multifilament and a stiff monofilament, on the same frame at the same tension, what travels up the arm is not of the same nature.
A string name tells you nothing. A number places it. Our range runs from N°1, the softest, a multifilament, to N°7, the most controlling, a stiff hexagonal. The seven are comparable with each other because they were measured on the same bench with the same protocol: eight strings, each characterised by its elongation curves, not adjectives.
For a sensitive arm, N°1 and N°2 are the two to look at first. Not because they are "comfortable" — the word measures nothing — but because their elongation curve shows greater stretch under the same load: contact lasts longer and tension builds more gradually.
If you currently play a stiff monofilament in a full bed, the most informative test is not to change racquets. It is to have a N°1 or a N°2 fitted to the frame you already own, and to play the same matches again.
Tension: the change that costs least
It costs nothing beyond a restring you were going to have done anyway.
Lowering tension lengthens contact time and softens the ball's exit. The usual fear — "I will lose control" — deserves to be tested rather than believed: in many games, a lower tension produces a higher, safer trajectory, and therefore more balls in the court. The tension question is asked backwards from the way most people put it.
A second point, less well known: a string loses tension and deforms well before it breaks. A monofilament played long past its useful window turns stiff and dead. Knowing when to restring is part of this subject.
Swingweight and grip size, the two that get forgotten
Swingweight decides how fast you have to set the racquet up. Too high for your timing and you are systematically late, catching up with the wrist and forearm. Too low and the racquet is pushed back at contact, so the impact is taken by the arm instead of being absorbed by the frame's inertia. It is not a "comfort" value, it is a timing value — and it is the one no product sheet gives you.
There is a name for what a frame opposes to that recoil, and it can be calculated: recoilweight, RW = SW − (mass/1000 × (balance − 10)²) — the inertia the frame keeps about its own centre of gravity. On a frame of 310 g balanced at 32.0 cm and measured at 320 swingweight, recoilweight is 170.0. Four grams at the tip, 66 cm from the butt, take it to 174.5: the racquet recoils markedly less — but swingweight rises to 332.5, and you have to be able to swing it. The same four grams in the handle, at 12 cm, take recoilweight to 171.5 and leave swingweight exactly where it was, at 320.0: less recoil, nothing paid in timing. A gram has no value in itself. It only has one in a place.
Grip size works more simply: a grip that is too small increases the grip force needed to hold the racquet, and that force is paid for further up. It is not a matter of preference, it is a matter of hand shape as much as hand size. We devote a whole article to it.
Both values can be set on your own racquet, without changing it: that is what a ProSetup tuning does, with the measured values recorded before and after.
Frame stiffness: what 69 RA means
RA is a flex index: the bare frame, unstrung, is pressed and its deflection recorded. It is not a measurement of what happens at impact, and the published figure is never the value you play — it is a comparison between frames, useful provided you know that. It is also one of the most misused numbers in tennis, because it gets pushed to both extremes, and both extremes cost you something.
Beyond 72, in what we measure on the bench, the frame barely flexes. It returns a lot of energy, fast — which looks good on a spec sheet — and it sends the vibration back into the arm. Contact is short and dry.
Under 62, it flexes a great deal. You think you are buying comfort; in fact part of the energy stays in the frame. The ball drops short when you brush up, you compensate by forcing, and the arm ends up paying for the compensation rather than the vibration.
Our six adult moulds are all at 69 RA. Firm without being stiff: firm enough for the ball to leave without forcing, soft enough that contact is not dry. It is not a soft compromise, it is a held position — why 69 and not something else is set out elsewhere.
Head size and string pattern: geometry counts too
Frame stiffness gets discussed constantly and geometry almost never. Yet it decides part of what travels back up.
A large head changes two things at once. It deforms its string bed more, so it returns more energy. And it allows impacts further from the frame's long axis: at the same ball speed, an off-centre hit three centimetres out produces twice the torque of one at a centimetre and a half. What the frame opposes to that torque has a name — twistweight, its inertia about the long axis. A large head often has more of it; it also gives far more occasions to call on it. It is a value that can be measured, and corrected by adding mass at three and nine o'clock.
An open pattern (16×19) lets the strings move. That is comfortable as long as the string is alive, and it turns dry once the notches deepen and snapback no longer happens. A dense pattern (18×20) is more stable over time but firmer at impact.
Neither configuration is better for the arm in the absolute. What matters is coherence between geometry, string and tension. A 16×19 strung tight with a stiff monofilament is harder than an 18×20 strung soft with a multifilament.
A dampener does not protect the arm, and that can be calculated.
An impact puts something in the order of eighty joules of kinetic energy into play — a 57-gram ball and a string bed meeting at more than fifty metres per second of relative speed. After separation, two things vibrate, and they are not the same thing.
The string bed oscillates at around 550 hertz. That is what you hear. Its moving mass is small and its amplitude is only a few tenths of a millimetre: the energy it carries is counted in thousandths of a joule, a few thousandths of one per cent of the impact.
The frame bends at around 140 hertz, with a far greater effective mass and a far larger amplitude at the handle. It carries roughly ten times more energy than the string bed — and it is that one, not the other, that travels up into the hand, the wrist and the forearm.
The dampener sits between two main strings, below the active area of the string bed. It damps the string mode, the only one it can reach: a few thousandths of a joule out of the eighty. It does not touch the frame's bending mode — three grams do not shift the modal behaviour of a frame that weighs three hundred.
What it does do measurably is add weight. Three grams placed forty centimetres from the butt add 2.7 points of swingweight — ΔSW = m × (d − 10)² — and eight tenths of a millimetre of balance. That is little, but it is the only real mechanical effect, and it belongs to tuning, not to comfort.
We are not saying you should take it out. Noise and feel count, and a player who plays better because the sound suits them has a good reason to keep it. We are saying you should expect nothing from it for the elbow.
When equipment is not the cause
This has to be said, because it is true in many cases.
Volume. Three sessions a week become five, or you come back after six months off. The equipment has not changed; the load has.
Surface and balls. Moving from clay to hard court, or new pressurised, heavy balls, noticeably change what arrives in the arm — with no value on the racquet having moved.
Cold, and no warm-up. A cold tendon takes it less well. That is not medical advice, it is a coach's observation.
Technique. It is the heaviest factor and the only one we do not handle. A backhand taken late, a wrist compensating, a serve hit with a locked arm: no measured value compensates for that, and nobody should sell you the opposite.
If you are in one of those four situations, changing string will only cost you time.
The order in which to change things
From free to expensive. One change at a time, with two or three sessions between each, otherwise you will not know what acted.
A health professional's opinion. Before everything else, and this is not a politeness.
Remove what is dead. A string played past its useful window, a flattened overgrip, a dampener that changes nothing: this costs nothing.
Change the string to a N°1 or a N°2, on the same frame. This is the strongest lever, and the cheapest.
Lower the tension by two or three kilos at the same restring. No more, and judged over several sessions.
Tune mass, balance and swingweight on the frame you own.
Check the grip size, and correct it with an overgrip or a handle made to your size if the gap is real.
Change the frame — last, and only if the measurements show yours is far from what would suit you.
We will not go further than that. We do not know whether your pain comes from equipment, from technique, from playing volume or from something else, and nobody can know that from a website. What we do know how to do is measure what you play and move one value at a time.
If your pain is not in the elbow, the broad article is the one to read: all upper-limb pain in tennis — shoulder, wrist, forearm — with the general order of the levers and what each costs. And if you would rather start from the numbers than from the vocabulary, the configurator asks six questions and returns a mass, a balance and a swingweight.
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