Introducing the Trunk Extension Machine

By Gus Diamantopoulos

At Renaissance Exercise^™, we maintain an unwavering dedication to engineering excellence and outstanding design. We adhere to the highest standards of developing exercise and rehabilitative equipment, and our hand-built machines exemplify the purest spirit of forward-thinking innovation.

With the release of our generic line of equipment, we have pushed the envelope and pulled all the stops to develop high-performance machines that operate and feel like nothing else on the market. From exclusive, custom resistance profiles, to meticulous craftsmanship using the finest materials, to peerless design characteristics and biomechanics, these machines literally bring to life Ken Hutchins’ extraordinary protocol and philosophy.

Now, the Renaissance Exercise team is proud to present a groundbreaking exercise machine that challenges many of the most revered notions of spinal exercise and rehabilitation, and demands a critical re-examination of the conventional wisdom.

Game Changer

 Introducing the RenEx Trunk Extension machine by Renaissance Exercise Equipment, Ltd.

The RenEx Trunk Extension machine enables the user to perform a general posterior movement whereby the trunk, pelvis, and hips rotate collectively. The machine not only provides an intelligent and revolutionary restraint system that cleverly reduces more-common, aggressive restrictions, but also amazingly permits a greater comparative total excursion than any device from any manufacturer. It combines enhanced mechanical performance, advanced technologies for force measurement, and a radical, assertive design that provides a truly inimitable workout experience for the user.

This is the evolution of strengthening exercise for the lumbar spine and beyond.

Notwithstanding the elaborate engineering of the unique restraint system, the RenEx Trunk Extension machine’s function is remarkably simple, direct and intimate. By distilling the general idea of torso extension to its essence and amplifying every aspect of performance, Ken Hutchins has created the ultimate flagship machine for Renaissance Exercise Equipment, Ltd.

 

 

 

 

 

 

 

 

Although there are similarities to existing lower-back machines, the RenEx Trunk Extension truly differs from all other machines that provide extension-type exercise. Other machines specifically attend to the hips or the pelvis, the lumbar spine or the thoracic spine. They may address one or two but never all four components collectively.

By contrast, a subject exercising on the RenEx Trunk Extension produces movement through an anatomically collective focus, rather than a specific one. Instead of trying to physically block the contribution of the ancillary musculature, the RenEx Trunk Extension machine purposely encourages its recruitment by way of synergistic coupling. As a result, the user can experience a total range of motion with an astounding 122 degrees—more than any other machine has ever permitted—25 degrees of extension beyond anatomical neutral.

Witnessing a subject achieve such a degree of extension may prompt concern regarding the potential hazards of such “hyperextension.” Fortunately, Ken Hutchins has already tackled the contradictions relating to the topic of so-called hyperextension in his seminal article on the subject. In it, he artfully dispels much of the hysteria associated with fears over hyperextension by highlighting many of the inconsistencies surrounding the term, both in technical context as well as in emotional interpretation. Ken astutely poses the question, “If any position posterior to anatomical neutral is denoted hyperextension, then is any position anterior to anatomical neutral  considered hyperflexion?”

In fact, extension therapies such as the McKensie Extension Method have been applied with very good outcomes and demonstrate that extension is a cure for a host of back conditions, such as sciatica. And in more serious conditions such as spondylolithesis, where the vertebral bodies can shift anterio-posteriorly with grave consequences, observation shows that extreme extension is relieving for many patients while extreme flexion actually increases instability and pain.

Further, Hutchins has indicated that it was Arthur Jones himself who originally inspired the idea of a machine that permits greater extensional range of motion. Shortly before abandoning his work on the Nautilus Lower Back machine and starting MedX, Arthur suggested to Ken that the farther a human subject engages in extension, the greater the volitional decompression on the vertebral bodies.

Yet despite Jones’ contention regarding extension, avoidance of hyperextension has been a hallmark characteristic of lower-back-type machines from large exercise equipment companies such as Nautilus, MedX, Cybex and others. Ironically, these same companies overlook the fact that their very own abdominal-machine designs passively push the trunk into hyperextension—a much more grievous affair.

From 1986 to present, MedX has designed and marketed its machines for isolated lumbar dynamometry. These were the first effort-dependent systems for valid strength testing and specific rehabilitation of the lumbar spine. Some of these were made for measurement and exercise while some merely for exercise.

MedX has scientifically substantiated the concept that the best way to correct spinal debility, weakness and pain is strength training, and it is clear that the MedX approach has helped many with back issues. But it is also probable that many back issues may be better served with the deletion of most of the constraint and movement restrictions incorporated into the MedX machines.

The RenEx Trunk Extension machine represents an evolution in prior advances by machines like the Lumbar machine by MedX and the Nautilus Lower Back machine before it. It is the end result of collaborative and intense study, progressive discovery, and enduring dedication. The goal was to develop a machine that truly maximizes the potential for strengthening the entire trunk, including the lumbar, and addressing the limitations of existing equipment.

As such, we are interested solely in exercise and not at all with isolated testing. Thanks to MedX’s published research, we have peer-reviewed evidence that strengthening exercise indeed  corrects abnormal strength curves and resolves pain issues. In turn, this relieves us of the burden designing a machine for specific testing. Facilities for movement limitation, variable counter-weighting, stored-torque compensation, and tyrannically-restrictive constraint mechanisms are both unnecessary and undesirable.

Instead, we have been free to focus exclusively on designing the best tool for complete torso extension, performed safely and without compromise.

The RenEx Trunk Extension machine brings practices and principles from RenEx Equipment’s revolutionary generic line of equipment along with a host of radical designs and developments.

A handcrafted steel frame forms the bold, ultra-rigid foundation of the machine with an offset segment that contains the elaborate styling of the drive train, pulleys, resistance delivery system, and movement arm.

Protracting from the heart of the drive-train segment is the movement arm itself, which appropriately exceeds the range of motion of the torso. At the same time, it can be optionally stopped in fine-tuned increments or decrements to protect subjects with extensional as well as flexional limit issues.

Just astern of the subject’s right shoulder, you’ll find the superbly cut, crank-adjustable, variable cam that accommodates subjects’ variable endpoint resistance decrease requirements.

Ken’s proprietary cam design allows for the truest performance of the Renaissance Exercise protocol and provides the unique resistance variation that no other machine can provide. But it is the precision restraint system on the RenEx Trunk Extension that truly distinguishes the machine mechanically from any similar device.

The system encourages the subject to feel and use the buttocks, the hamstrings (rear of the thighs), and the entire mid-section to properly enable true torso extension, which includes volitional spinal decompression of the lumbar area particularly in extension. Every aspect of the restraint system works in synergy to promote better performance of the exercise. When combined with the Renaissance Exercise protocol, the subject can partake in a movement pattern that feels incredibly productive, safe and exhilarating.

A comfortable, adjustable-height thigh support is placed under the proximal thighs to permit full hip extension concurrent with spine extension, and a seatbelt arrests reactionary forces at the hip angle in such a way as to not delimit extension.

Note the conspicuous absence of a pelvic buttress as in the Nautilus Lower Back machine or a cylindrical pelvic pad as in the MedX Lumbar. Similarly note the absence of a clamping thigh pad. Such deletions contribute greatly to the ample freedom that a subject experiences in the RenEx Trunk Extension machine.

Toward the bow of the machine is the prominent lower leg complex of restraint and adjustment. The heart of the array is a vertically adjustable pedestal deck that articulates using a large hand-wheel. This ingeniously cantilevered design permits adequate access and safe entry/exit while simultaneously enabling precise and accurate positioning and repositioning—within 1/50 of an inch—without the subject being required to step higher than 3.5 inches. Its brilliant design utilizes components and force to lift and hold the largest subject plus the force of effort against the movement arm.

Incorporated into the pedestal deck is the innovative heel wedge, which places the ankles into maximum extension. This accurately and precisely ensures repeatability utilizing etched grids between the aluminum wedge and the pedestal. Positioning into maximum ankle position cleverly solves two problems at once: First, it prevents the subject from rising off the heels as the ankles are already run out as high as possible with depleted height potential. And second, maximum ankle extension locks the talus against the lower tibia and fibula in the ankle to preclude knee straightening as the proximal thigh is held downward by the seat belt. As an added bonus the wedge conveniently flips back to retract out of the way for easier entry/exit. For special populations who cannot tolerate heel elevation, a calf restraint serves to optionally prevent leg straightening.

 

 

 

 

 

In comparison, Medx approaches heel-raising issues with a thigh constraint that forces the heels down onto the pedestal and approaches the leg-straightening issue with an adjustable pressure against the tibial tuberosities that transmits through the femurs and pelvis to blunt the posterior movement of the buttocks. While effective at blocking both of the unintended actions, note that the constraints do not curtail the subject’s inappropriate volition (the efforts to raise the heels and straighten the legs) but merely blunts the movement that is powered by the volition.

Additionally with the RenEx Trunk Extension machine, both the user and the instructor benefit from the ergonomic positioning apparatus. The user experiences a greater overall comfort and the instructor can quickly, easily, and precisely take the necessary steps for accurate prescription of the appropriate settings.

Of course, once the subject is properly positioned, resistance can be masterfully delivered upon loading via the patented Ultraglide® top plate and Freedom Stack® for near-frictionless weight- stack operation, complete with a self-aligning tuner for repeatable performance on every single repetition. And integrally-mounted incremental add-on weights mean quicker resistance selections by the instructor for ultimate efficiency in machine setup.

As a dynamic exercise and rehabilitation machine, the RenEx Trunk Extension is in a class of its own, but it doesn’t end there. Optionally, the machine also possesses force measurement capabilities to facilitate real-time feedback in startup loading, end-point isometric techniques and fully- recordable and comparable performance of Timed Static Contraction (TSC) exercise.

It should be noted that while isometric exercise is very valuable for many patients, including those who experience pain with movement, the traditional approach to isometrics has been a contraction duration that is too short and too violent due to abrupt application. Our isometric techniques bear no resemblance to the static tests used to plot strength curves. The TSC protocol by Renaissance Exercise stages the subject’s effort over longer durations to provide infinitely safer, more intense, and more productive exercise for any subject, weak or strong.

The all-new RenEx Trunk Extension machine reflects a clarity of vision that defies preconceptions of anatomical function and reconstructs the idea of how to safely and effectively strengthen the human spine. It is a blend of elegant design, intuitive mechanics, and innovative thinking. Whether your goal is to engage in pure exercise with limitless intensity or to attend to the most delicate and sensitive cases for back pain or debility, the RenEx Trunk Extension machine by Renaissance Exercise Equipment, Ltd. is the solution.

*Several patents are pending*

Tagged as: Ken Hutchins, Low Back Exercise, Lumbar Extension, MedX, Nautilus, Renaissance Exercise, Trunk Extension