Patents & proof
Four U.S. patents. One measured result.
Springbak® is not a cushioning story. It is a claimed material system — 1,4-polybutadiene bonded into a resilient, full-length layer — that laboratories measured for stability, strength and stride. Below are the patent numbers, the investigators, what they found, and the coaches and athletes who tested it in training and competition.
- 4
- U.S. patents
- 2×+
- Force to displace
- 1990
- First filing
- 3/32 in
- Profile
The patent family
All four patents were issued to inventor William R. Crow — the first patents issued under the performance-enhancing athletic shoe component category. Each filing is public record; every number below links to the published document.
- Energy return chemistry
Patent 1 of 4 · Granted 1996
U.S. Patent No. 5,554,694
“Performance enhancing athletic shoe components and methods”
The foundation of Springbak® technology
The original filing that established the performance-enhancing athletic shoe component category: 1,4-polybutadiene combined with a resilient rubber, formulated to return energy rather than only absorb it.
Read U.S. 5,554,694What it covers
- 1,4-polybutadiene plus natural, isoprene, nitrile or EPDM rubber compositions
- Components formed as midsoles, soles, insoles and shoe inserts
- Methods of making the components
- Inventor
- William R. Crow
- Filed
- December 21, 1990
- Granted
- September 10, 1996
- Energy return and placement
Patent 2 of 4 · Granted 1997
U.S. Patent No. 5,695,850
“Performance enhancing athletic shoe components and methods”
Placement beneath the foot
Refined where the resilient component belongs: in the shoe, beneath the ball of the foot — the load path that drives push-off, jumping and change of direction.
Read U.S. 5,695,850What it covers
- Component placement between the athlete's foot and the shoe sole
- Insole, midsole and shoe-insert applications
- High-resilience rubber blends for lightweight components
- Inventor
- William R. Crow
- Filed
- January 29, 1993
- Granted
- December 9, 1997
- Layered construction
Patent 3 of 4 · Granted 2000
U.S. Patent No. 6,120,880
“Performance enhancing athletic shoe components and methods”
The layered construction
Added the multi-layer architecture: an upper 1,4-polybutadiene layer bonded to a resilient layer running substantially the length of the shoe, with an optional third layer or coating.
Read U.S. 6,120,880What it covers
- Upper polybutadiene layer bonded to a full-length resilient layer
- Optional third layer or surface coating
- Constructions for speed, jumping and explosive movement
- Inventor
- William R. Crow
- Filed
- August 7, 1998
- Granted
- September 19, 2000
- Performance methods
Patent 4 of 4 · Granted 2003
U.S. Patent No. 6,589,630 B1
“Performance enhancing shoe components and methods”
Methods of increasing exercise performance
Broadened the family from the component itself to methods of using those components to increase exercise performance — the claim set most relevant to footwear brands evaluating integration.
Read U.S. 6,589,630 B1What it covers
- Methods of using the components to increase exercise performance
- Polybutadiene layer with optional high-energy-returning rubber and coating
- Integration into inserts, insoles, midsoles and sole components
- Inventor
- William R. Crow
- Filed
- June 23, 2000
- Granted
- July 8, 2003
From patent to performance
The claims describe resilient components for inserts, insoles, midsoles and soles. Springbak® chose the version an athlete can adopt without giving anything up: a 3/32-inch layer fitted beneath a removable liner or on top of a firmly bonded or stitched liner. Same shoe, new platform. See how it works.
The balance and stability study
This is the study that matters most outside of sport, and it pairs directly with the patented construction. Evaluated with Dr. Michael Yessis, Dr. Robert Wiswell and Howard Gray, PhD.
Method
Subjects stood on a force plate in their own footwear and then on Springbak® Springsoles. Investigators measured the horizontal force required to displace the subject from a balanced stance — a direct read on standing stability and functional strength rather than a self-reported feeling.
Finding
It took more than twice the force to push subjects off the force plate while they stood on Springsoles. The reviewing investigator concluded there is a significant strength and stability increase for individuals using Springsoles under laboratory conditions.
“Our department sponsored a strength and stability study at the Weber State University human performance lab. After reviewing the force plate data, showing it took more than twice the force to push off the subjects off the force plate when standing on Springsoles, we have to conclude there is significant strength increase to individuals utilizing Springsoles.”
Which patent this speaks to
Stability is a property of the platform under the foot. U.S. Patent No. 6,120,880 claims the layered, substantially full-length resilient construction that creates that platform, and U.S. Patent No. 6,589,630 B1 claims methods of using those components to increase exercise performance. The force plate data is the measured expression of both.
Treadmill stride analysis
University of Southern California · Dr. Robert Wiswell
Method
Athletes ran a fixed distance on Springsoles and on visually identical placebo inserts while stride counts were recorded, so the comparison isolated the insert rather than the shoe.
Finding
Athletes wearing Springsoles took fewer strides over the same distance than with placebo inserts — the pattern you expect from increased stride length at the same effort.
“Athletes wearing Springbak Springsoles took fewer strides over the same distance than when wearing placebo inserts — consistent with increased stride length.”
Lab footage and the legacy film
See the Springbak® Difference in Action
How patented Springbak® technology is designed to work beneath the athlete's foot during running, jumping, lifting, and cutting.
The Springbak® Legacy Film
Filmed at Northstar Studios in Nashville: founder Bill Crow's vision, six years of R&D, and the athletes, coaches and researchers who tested it.
What they said
"Our department sponsored a strength and stability study at the Weber State University human performance lab. After reviewing the force plate data, showing it took more than twice the force to push off the subjects off the force plate when standing on Springsoles, we have to conclude there is significant strength increase to individuals utilizing Springsoles."
Force-Plate Stability Study
In force-plate testing, subjects standing on Springbak® Springsoles showed more than twice the overall resistance to being pushed from their position.
In plain English: they were harder to move. They could hold their ground better against a sideways push—exactly the kind of stability athletes need when planting, cutting, jumping, landing, and absorbing contact.
Springbak® gives the foot a more stable, responsive platform to work from inside the shoe.
Results are from the force-plate testing described in U.S. Patent No. 6,589,630 B1. Individual results vary.
"Athletes wearing Springbak Springsoles took fewer strides over the same distance than when wearing placebo inserts — consistent with increased stride length."
"The design of athletic shoes is becoming increasingly important to the performance of athletes. Shoes that enhance performance by only a few tenths of a second, or a few inches, can provide the winning edge."
"One innovative idea grew into a patented, ultra-thin performance product used by athletes across many different sports."
"Small advancements in athletic footwear can translate into meaningful gains on the track. That is the space Springbak works in."
"Springbak addresses the ground contact side of performance — the part most training programs never touch."
"I can run faster, jump higher, and have less fatigue. I would highly recommend Springbak® Springsoles to enhance athletic performance."
"While an assistant coach at BYU I tested spiking speed of our men's volleyball team with a speed gun. After an hour of testing it became apparent that they were hitting 5% faster in Springsoles."
"There is no doubt in my mind after testing and hearing the athlete's feedback that your innersoles help our athletes jump higher and move quicker."
"We love Springsoles from Springbak®. We have been using them for an explosive team."
"The players felt that they have enhanced their performance from using Springsoles both in terms of jump height and injury prevention. The extra inches gained from Springsoles may have been differences that enabled the New Zealand Men's team to beat Australia for the first time."
"Immediately after putting on the insoles the players on the team could feel the added cushioning and energy return and their confidence level soared."
For footwear manufacturers
The family was never written only for an aftermarket layer. The claims read on components formed as midsoles, soles, insoles and inserts — the technology can be built into a shoe at manufacture rather than added to it afterward. Springbak® has three decades of formulation, tooling and laboratory data behind that construction.
Patent and testing FAQ
- Is Springbak® patented?
- Yes. Springbak® Springsoles are built on four U.S. patents issued to inventor William R. Crow: Nos. 5,554,694 (1996), 5,695,850 (1997), 6,120,880 (2000) and 6,589,630 B1 (2003), titled "Performance enhancing athletic shoe components and methods." They cover 1,4-polybutadiene and resilient rubber compositions used as shoe inserts, insoles, midsoles and sole components, and methods of using them to increase exercise performance.
- What did the balance and stability study find?
- Force plate testing at the Weber State University Human Performance Laboratory found it took more than twice the horizontal force to displace a subject standing on Springsoles compared with their own footwear alone. The balance and stability work was evaluated with Dr. Michael Yessis, Dr. Robert Wiswell and Howard Gray, PhD, who concluded there is a significant stability and functional strength increase under laboratory conditions.
- Which patent covers balance and stability?
- Balance and stability come from the same claimed construction rather than a separate filing. U.S. Patent No. 6,120,880 covers the layered full-length resilient construction that stabilizes the foot's platform, and U.S. Patent No. 6,589,630 B1 covers methods of using those components to increase exercise performance — the claims the force plate stability data speaks to.
- Are Springsoles a full replacement insole?
- No. Springsoles are a 3/32-inch performance layer. Put them beneath a removable factory liner; leave a firmly bonded or stitched liner in place and put the Springsole on top. Full replacement insoles remove and replace the shoe's own insole.
- Can footwear manufacturers license or integrate the technology?
- The patent family expressly covers components integrated into midsoles, soles and inserts at manufacture, not only aftermarket layers. Manufacturers evaluating integration can reach Springbak® at info@springbak.net or (951) 277-3000.
Stand on the patents
Same shoes. New performance platform. Test it on yourself — individual results vary, which is exactly why you baseline first. Springbak® beneath your feet.
Shop SpringsolesStudy summaries describe laboratory evaluations of Springbak® Springsoles conducted with the named investigators. Individual results vary. Springbak® Springsoles are performance footwear components and are not a medical device, and no claim is made to diagnose, treat or prevent any condition.