Basketball Dunk Technique: Approach, Takeoff, and Finish
Good dunk technique means a controlled, accelerating approach, a powerful penultimate step that converts horizontal speed into vertical lift, and a strong two-hand or one-hand finish at the peak of the jump. Formfix checks all of this from a single iPhone video or photo and returns a 0–100 score with the #1 thing to fix in under 15 seconds.
Dunking is a skill layered on top of vertical jump ability — approach mechanics alone can add inches. This page covers what good technique looks like, the mistakes that cost you height, and how to film your attempts for analysis.
Download Formfix on the App StoreWhat good basketball dunk form looks like
Accelerating approach
You build speed through 3–4 strides — controlled, not sprinting flat-out — so the takeoff can convert speed into lift.
Long penultimate step
The second-to-last step is long and low, dropping your hips and loading the legs like a spring.
Quick, blocked plant
The final step plants slightly ahead of your hips and blocks hard — braking the forward momentum so it goes up, not forward.
Arm swing
Both arms swing back on the penultimate step and rip upward at takeoff — the arms contribute real inches.
Tall, extended body at the rim
You reach full extension at the peak — hips through, arm long — finishing at the highest point of the jump, not on the way down.
Controlled landing
You land on both feet under the rim, knees soft, absorbing the landing — not crashing off-balance.
Most common mistakes and how to fix them
Approach too fast
Why it happens: Sprinting in out of control means the plant can't convert the speed — you just run past the jump.
Fix it: Cue 'build speed, don't max it.' Practice approaches at 80% and focus on the last two steps — the penultimate and plant are where height comes from.
No penultimate step
Why it happens: Taking two same-length steps at the end skips the hip drop that loads the jump.
Fix it: Cue 'long, then short.' Mark your last two steps on the floor: the penultimate should be noticeably longer and lower than the plant step.
Planting under the hips
Why it happens: A plant directly under your body lets you keep moving forward instead of blocking upward.
Fix it: Cue 'plant ahead, sit back.' The plant foot should land slightly in front of your hips so your momentum has to go up.
Leaving the arms out of it
Why it happens: Jumping without an arm swing leaves free height on the table.
Fix it: Cue 'swing back, rip up.' Practice standing vertical jumps with a full arm swing — then carry the same swing into your approach.
Reaching too early
Why it happens: Extending for the rim on the way up means you arrive at the rim at less than full extension.
Fix it: Cue 'jump first, reach at the top.' Time the reach for the peak of the jump — film from the side to see where in the jump you're actually extending.
How to film it for analysis
Camera angle
Side-on, perpendicular to your approach, at chest height — this shows the penultimate step, plant position, and extension at the rim in one view.
Distance
15–20 feet (4.5–6 m) away, framing the full approach, the takeoff, and the rim.
Framing
Keep the phone still and film several attempts, including misses — the difference between a make and a miss is usually visible in the last two steps.
FAQ
How can I improve my dunk technique?
Most dunkers lose height in the last two steps: make the penultimate long and low, plant slightly ahead of your hips, and swing your arms hard. Film from the side — the approach is almost always where the inches are hiding.
Is it easier to dunk off one foot or two?
One foot favors speed and long approaches; two feet favors power and shorter approaches. Most people are naturally better at one — film both and compare your jump height and control.
How high do I need to jump to dunk?
You need your wrist at or above rim level to dunk comfortably — roughly your standing reach plus a vertical that closes the gap to about 6 inches above the rim. Technique improvements in the approach often add inches before any training does.
Why do I jump higher without the ball?
Carrying the ball changes your arm swing and timing. Practice approaches with the ball at lower rims, keeping the same arm swing you'd use without it.
How do I film my dunk for a form check?
Side-on at chest height, 15–20 feet back, phone still, approach and rim in frame. Upload to Formfix for a 0–100 score and the #1 fix in under 15 seconds.
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