TheraBand FlexBar: What the Research Actually Shows

Updated September 30, 2026

The TheraBand FlexBar is a ribbed rubber cylinder about a foot long that you twist against
itself. It costs roughly what two overgrips and a can of balls cost, it is the most recommended
object in every pickleball-elbow thread on the internet, and the evidence behind that reputation
is smaller and more mixed than the marketing implies.

We have not run a trial on it. What follows summarises the published research and the
manufacturer’s own protocol, attributed in each case. None of it is medical advice — persistent
elbow pain is worth taking to a clinician rather than to a rubber bar and a forum thread.

What it is and what the exercise is

The bar comes in four resistances — yellow, red, green, blue, lightest to heaviest.
Performance Health, which manufactures it, suggests most women start at red and most men at green
for the exercise it is best known for.

That exercise is the Tyler Twist. Hold the bar vertically in the sore arm with
the palm facing in, grip the top with the other hand palm facing out, twist with the healthy upper
hand, extend both arms so the bar is horizontal, then let the bar untwist slowly using
the sore side while the healthy side holds tension. The protocol is 10–15 repetitions, three
sets, daily, moving up a resistance level once the current one is comfortable.

The slow release is the whole exercise. Everything else is setup. What is being loaded is the
lengthening phase of the wrist extensors — an eccentric contraction — and that loading
pattern, not the rubber, is what the research is about.

The study everyone quotes, and what it actually was

The reputation traces to a single trial: Tyler and colleagues, published in the Journal of
Shoulder and Elbow Surgery in September 2010, out of the Nicholas Institute of Sports Medicine
in New York. Twenty-one patients with chronic tennis elbow, all receiving standard
physical therapy for seven weeks, with one group adding the FlexBar exercise.

The reported results are striking. Performance Health summarises them as an 81% improvement in
pain for the eccentric group against 22% for standard treatment, 76% against 15% on disability
scores, and 79% against 15% on strength — with the trial stopped early so that everyone
could receive the eccentric protocol.

Three things to hold in mind alongside those numbers. The sample was twenty-one people. The
summary above is published by the company that manufactures the bar. And the comparison was
eccentric exercise plus standard therapy against standard therapy alone, which is a test
of adding the exercise, not a test of the bar against other ways of doing the same exercise.

A more recent comparison is less flattering

A 2024 comparative study published in Cureus put 30 participants into two groups, one
performing plyometric exercises and one performing TheraBand FlexBar exercises, both alongside
ultrasound, measured on the Patient-Rated Tennis Elbow Evaluation and a visual analogue pain scale.
The plyometric group did better, at p<0.001.

That does not mean the FlexBar does nothing — both groups improved. It means the bar is
one way to load a tendon and not obviously the best one, which is a very different claim from the
one the product’s reputation carries. The consistent finding across this literature is that
progressive loading of the extensors helps; the delivery mechanism is negotiable.

Why pickleball produces this problem at all

The sport loads the wrist extensors in a specific way: a light paddle, a high shot count, and a
lot of blocked balls taken out in front with the wrist holding a firm position against the ball’s
pace. It is a volume problem more than a force problem, which is why it tends to arrive after
someone moves from twice a week to five times a week rather than after one hard session.

That pattern explains why the eccentric protocols have any claim on the problem. Tissue that is
being asked to absorb load repeatedly gets better at it when the load is applied progressively and
worse at it when the load is only ever applied during play. It also explains why rest alone
frequently disappoints people: three weeks off reduces the symptoms and does nothing about the
capacity that was short in the first place.

The other two contributors are equipment and technique, and they are worth naming because
neither is fixed by a rubber bar. On equipment, the two variables that change forearm load are grip
circumference and how much vibration reaches the hand. On technique, the common culprit is a late
contact point — reaching for a ball rather than moving the feet to it puts the wrist in the
weakest position available, at the moment the most pace is arriving. A coach can spot that in about
ten minutes; a bar cannot.

None of which is a reason to skip the bar. It is a reason to treat it as one of three levers
rather than the fix.

So is it worth buying?

Yes, on convenience. At its price it is the cheapest way to get a repeatable,
progressively loadable eccentric exercise into a bag or a desk drawer, and adherence is most of
what makes any rehab protocol work. A tool you will actually use daily beats a better protocol you
will not. The four resistance levels give you somewhere to go as it gets easier, which a fixed
weight does not.

No, if you are expecting the bar to be the active ingredient. Nothing in the
research says the rubber is special. If you already own dumbbells and will use them, you have the
equipment.

You can check current FlexBar listings and resistance levels — pick the resistance rather than the cheapest one, because
starting too heavy is the most common way this gets abandoned in week one.

Where it fits against the other things sold for a sore elbow

A counterforce brace and a FlexBar do opposite things. The brace redistributes load during play
so you can keep playing; the bar loads the tendon deliberately, away from play, to build capacity.
One is a symptom tool and one is a training tool, and buying the first while skipping the second is
the usual mistake. We compared the strapping options in our
guide to
elbow braces, supports and sleeves.

The third lever is equipment fit, and it is the one players skip. A grip that is too small makes
you squeeze the handle, and squeezing is the mechanism behind most of the forearm load in this
sport — our
grip
and overgrip guide covers sizing, and
whether ProKennex’s
vibration-damping technology actually does anything looks at the paddle-side claims with the
same scepticism applied here.

Using it without wasting the first month

• Start lighter than you think. Red for most people, green if you are confident
  and symptom-free at red. The bar is not a strength test.
• The release is the rep. Three to four seconds letting the bar untwist. If it
  snaps back, the set did nothing.
• Daily beats heavy. The protocol is built on frequency, three sets of 10–15,
  every day.
• Do it away from play, not during. Loading a tendon and then playing three games
  on it is not a rehab plan.
• Expect weeks, not days. The trial above ran seven weeks. Two days of twisting a
  rubber bar proves nothing either way.

If pain is sharp, wakes you at night, or has not moved after several weeks of consistent
loading, that is the point to see a physiotherapist or physician rather than to buy a heavier bar.
At 4.7 I play enough volume to take that threshold seriously; the players I know who lost a season
to an elbow are, without exception, the ones who kept playing through it and treated equipment as
the fix.

Nothing here is a substitute for individual medical advice. Study details are attributed to the
sources named; see how we evaluate
gear.

How we review gear — including how we get the paddles we test and what the money never touches — is documented in our review methodology.