Barbell vs EZ-Bar Curls: Why Straight Bars Hurt the Pinky Side of Your Wrist

Barbell vs EZ bar curls is mostly a wrist question, not a biceps question. The research we have shows similar biceps activity on both bars, so if a straight bar makes the pinky side of your wrist ache, switching to an EZ-bar costs you very little.

This article sits inside our complete arm and forearm training guide. Here we stick to one controversy: why a rigid straight bar bothers some wrists, what the evidence does and does not show, and how to fix it without losing arm growth.

Does the EZ-bar build the same biceps as a straight bar?

Almost certainly close. That is the honest summary, and it is a hedge on purpose.

In a 2018 study, 12 participants did a set of 10 curls at 65% of their 1-RM with a dumbbell, a straight bar and an EZ-bar while researchers recorded surface EMG from the biceps brachii and brachioradialis. The EZ-bar produced higher activity than dumbbells in both muscles, and the authors noted that the small difference between straight and EZ-bar variants makes the choice “a matter of subjective comfort” (Marcolin et al., 2018).

Two caveats matter. It was one set in 12 people, not a trial over months. And EMG measures electrical activity, not muscle growth. No long-term study I found compared biceps size after training with each bar, so “equal hypertrophy” is a reasonable expectation, not a proven result.

Why do straight barbell curls hurt the pinky side of the wrist?

Here is the mechanical picture. Stand with your arms hanging and palms forward. Your forearms angle slightly outward from your upper arms. That is the carrying angle, and it varies between people. A straight bar asks both wrists to sit in full supination, parallel and shoulder-width, no matter what your arms would prefer.

For some lifters that means the forearms are forced into a position they would not choose, and the load sits through the outside (ulnar) edge of the wrist. This is the part I want to be careful about. It is a plausible explanation, not a measured one. I could not find a study that measured wrist loading for straight versus EZ-bar curls.

What we do know comes from sports medicine reviews. Ulnar-sided wrist pain is common in athletes, and repetitive forearm rotation, wrist flexion and extension, and radial and ulnar deviation can predispose to injury of the ulnar structures (Dineen and Greenberg, 2020). Another review lists sports that need repeated pronosupination, deviation, axial loading and gripping, with the triangular fibrocartilage complex, the extensor carpi ulnaris tendon and the distal radioulnar joint among the structures commonly affected (Rios-Russo et al., 2021).

Neither review is about curls. The link is an inference, and a cheap one to test.

What does forearm position do to the biceps?

Supination is part of the biceps job, and that is why we like it for curls. The biceps both bends the elbow and rotates the forearm toward palm-up.

Ten competitive bodybuilders did 6-rep sets at 8-RM with supinated, pronated and neutral handgrips. During the lifting phase, biceps brachii excitation was about 19% greater with a supinated grip than with a pronated one and about 12% greater than neutral. The brachioradialis was a smaller 5 to 6% higher in supination. The front delt worked harder with the pronated and neutral grips (Coratella et al., 2023).

A separate 2025 study in 36 healthy men used light isometric holds. It found that the biceps looked more active in supination and the brachioradialis in pronation, and its authors called for further controlled work (Chen et al., 2025).

The practical reading: a fully supinated grip is the best for the biceps, the EZ-bar sits between supinated and neutral, and the gap is small enough that comfort can win.

Different studies, different results on exactly how big the grip effect is. That makes sense. Sample sizes are small, the loads differ, and EMG from different grips is not perfectly comparable. Treat the numbers as direction, not precision.

Straight bar vs EZ-bar: how they compare

	Straight bar	EZ-bar	Dumbbells or cables
Forearm position	Full supination, fixed	Partly supinated, fixed	Free to adjust
Biceps EMG	Similar to EZ-bar	Similar to straight bar	Somewhat lower than EZ-bar in some phases in one study
Wrist comfort	Bothers some lifters	Often easier	Often easiest
Loading small jumps	Easy with plates	Easy with plates	Needs a dumbbell rack or cable stack
Best for	Lifters with no pain	Lifters with pinky-side pain	Anyone who wants freedom of path

Dumbbell and cable comfort claims in the table are coaching observations, not trial results.

How do I fix wrist pain when curling?

Go in order. Do not change four things at once, or you will not know which one helped.

1. Swap the bar. Use an EZ-bar on the inner or outer bend and keep the same weight for two or three sessions.
2. Check the wrist line. A common mistake here is letting the wrists curl back toward the forearm as the set gets heavy. Keep the knuckles stacked over the forearm.
3. Lower the load. Biceps growth is not tied to one narrow rep range. A 2021 review argues muscle adaptations can be obtained across a wide spectrum of loading zones (Schoenfeld et al., 2021). So 12-15 reps with a lighter bar, taken close to failure, is a fair trade for a healthier wrist.
4. Change implements. Dumbbells let each hand rotate where it wants. Cables keep tension on the biceps and let you tweak the grip. Our article on Bayesian cable curls covers that option.
5. Slow the eccentric. If pain shows up on the way down, control the lowering phase. Do not drop the bar.

Pronated, neutral or supinated: which one should I use?

You do not have to choose one forever. Different grips emphasise different muscles, so rotating them is a legitimate way to spread the stress.

• Supinated (EZ-bar or straight bar): the biceps-first option, with the most biceps excitation in the study above.
• Neutral (hammer curls): friendlier for many wrists, and it brings in the brachialis and brachioradialis. See our guide to hammer curls and upper arm thickness.
• Pronated (reverse curls): less biceps, more forearm. Useful as an accessory, not a replacement.

If you want the anatomy behind why those muscles respond to grip changes, our functional anatomy of the arm flexors article goes through it. For curl variations that train the biceps at different lengths, see incline curls versus preacher curls.

Barbell vs EZ-bar curls for Indian gyms

Many commercial gyms in India have plenty of straight bars but only one or two EZ-bars, and those are often in use. If the EZ-bar is taken, ask for the cable rope or straight cable bar attachment. A cable curl with a short straight bar still lets your wrists float a little. If your gym has only fixed barbells, dumbbells are the free fix.

Also, do not underestimate the heat and humidity. Sweaty hands slip, and a bar that slides in your grip makes you squeeze harder, which can make wrists sorer. Chalk or a dry towel is a small, cheap help.

When wrist pain means stop and see a doctor

Ordinary training discomfort tends to fade within days of changing the setup. Pain that behaves differently needs a clinician.

See a doctor or physiotherapist if you notice:

• swelling or visible puffiness on the pinky side of the wrist
• clicking, snapping or a catching feeling
• numbness, tingling or weakness in the hand
• pain at night or at rest
• pain after a fall or a sudden twist
• no improvement after a week or two of sensible changes

Pinky-side wrist pain has several possible causes, from tendon irritation to cartilage and joint problems, and one of the reviews above notes that abnormal imaging findings can also appear in athletes with no symptoms, so an exam matters. Early treatment is usually non-surgical and often includes splinting, load management and activity modification (Rios-Russo et al., 2021). We cannot diagnose you here.

If the pain sits at the front of the elbow instead, our article on distal biceps tendonitis and golfer’s elbow is the better starting point.

How to program curls once the wrists calm down

Do not overcomplicate it. Two to four hard sets of curls, two or three times per week, is a reasonable start for most lifters. Our free training volume calculator can help you count your weekly sets across muscle groups.

Pick one main curl, such as the EZ-bar. Add a neutral-grip curl to fill the gap. Stay a rep or two from failure on most sets, and push the last set of the session closer to failure. Log your weights. If your logbook shows reps and load rising every few weeks, the bar choice is working.

If you are building a full pull session, our pull day plan shows where arm work fits.

The bottom line

The research on barbell vs EZ bar curls is small but consistent: biceps activity is similar, and a fully supinated grip adds only a modest amount. The wrist side of the story is less well studied, so the case for the EZ-bar rests on anatomy, reviews of ulnar-sided wrist pain and plain comfort. Change one thing at a time, keep your wrists straight, and see a clinician if the pain has red flags.