Extrinsic vs. intrinsic

Strength vs. Movement

While extrinsic muscle fiber is about strength. Intrinsic fiber is about movement.

Bigger vs. Stability

Extrinsic muscle fiber makes us bigger and stronger...intrinsic fiber contributes to mobility and stability.

Skeletal vs. Proprioceptive

Extrinsic muscle fiber is contracting skeletal muscle fiber. Intrinsic muscle fiber is proprioceptive lengthening muscle fiber.


Injuries, over-use and muscle imbalances turn-off intrinsic muscle fiber and lead to muscle tightness. 

The only way to restore the tight proprioceptive muscle fiber is to reboot intrinsic muscle with diagonal isometric force.

shop standing firm®

Activate Deep Glute Fiber

Rotational isometrics reboot intrinsic muscle fiber to strengthen weak links. 

Restore Explosive Strength of Hips

Intrinsic muscle activation recovers range of motion.

Improve Stability Strength Knees

Intrinsic muscle fiber provides neuromuscular strength and stability.

Customer comments

Rotation Standing Firm power glute stretch hip muscles external hip rotation PNF mobility

Great Glute Product

"I use StandingFirm® for deep glute activation with my athletes."

Josh Seligman MS, ATC, RSCC 

Major League Specialist Milwaukee Brewers

Immediate Response

"We have done exercises with our players and have seen an immediate response."

Aaron Nelson ATC, NBA ATC of the Year

Head Athletic Trainer Phoenix Suns

PreGame and Strength Routines

"We use the StandingFirm® in our pre-game and strength training routines."

Joe Kessler MS, ATC

Major League Strength and Conditioning Coach

Cleveland Indians

Stretch and Strengthen the Hip

"StandingFirm® is able to stretch and strengthen the hip area with various ranges of motion and resistance, something that is very hard to do."

Gavin MCMillian Founder Sports Science Lab

San Juan Capistrano, CA

WIRED magazine

Athleticism doesn't just come from the weight room...and is not always enhanced by cardio

...read more.

STACK magazine...a magazine by athletes for athletes

Dedicating some time off the links and in the weight room has become common among  elite golfers. Now there's a product focused on improving specific....read more


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