Double-ArmKettlebell Back ExtensionGrind

Jefferson Curl

Quick Answer

GrindKettlebell Back Extension

Feels Like

A steady strength rep: set starting position, then segmental curl downward, and control the rebuild spine from sacrum upward.

Main Muscles

Spinal erectors

Photos (8)

Adjusting the dials updates the Muscle target & Joint actions below.

Exercise Execution (3 steps)

Setup

Execution

Return

Muscle targetas performed — open Program to explore

IliocostalisPrime

LongissimusPrime

SpinalisPrime

Adductor Magnus2nd

Biceps Femoris (Long Head)2nd

Gluteus Maximus2nd

Interspinales2nd

Latissimus Dorsi2nd

Quadratus Lumborum2nd

Rotatores2nd

Semimembranosus2nd

Semispinalis Thoracis2nd

Semitendinosus2nd

Stabilizers — held, not moved

Biceps Femoris (Short Head)DiaphragmDorsal Interossei (Hand)External ObliqueFlexor Digiti Minimi Brevis (Hand)Flexor Digitorum ProfundusFlexor Digitorum SuperficialisGastrocnemiusGracilisIliacusInternal ObliqueLumbricals (Hand)MultifidusPalmar InterosseiPectineusPelvic FloorPlantarisPopliteusPsoas MajorRectus AbdominisRectus FemorisSartoriusTensor Fasciae LataeTransversus AbdominisVastus IntermediusVastus LateralisVastus Medialis

Joint actions — updates with your dials

Spine ExtensionHip ExtensionFinger FlexionHip FlexionKnee ExtensionKnee FlexionSpine Flexion

Not sure your Jefferson Curl is right? Get your form checked.

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