Luke Boldman hiking through a canyon with the Mountainsmith Day TLS lumbar pack
A lumbar pack allows the user to hike with an uninhibited upper body.

It seems that in 2013 and even around the Mountainsmith office, the terms lumbar pack and fanny pack have become interchangeable.  Though we won’t be offended if you call our iconic Day TLS a fanny pack, this is technically not a true statement according to the US Patent Office.  Thanks to the legal work of Mountainsmith’s founder, Patrick Smith, the company filed for and won a patent for a Self-Supporting Lumbar Pack in 1996.

A Fanny Pack is not a Lumbar Pack

Though Mountainsmith lumbar packs do not come to mind anymore for backcountry ski days, this was actually their first intended purpose when they were developed in the early 1980s.  Patrick Smith is an avid skier, and through his need to carry essentials while skiing Colorado’s backcountry, he created a pack that could be carried around the skier’s waist, allowing the skier to descend with an uninhibited upper body.

On May 5, 1982, Paul Ramer and I were blazing trails on the Colorado Haute Route. I was Telemarking, he was Alpine touring. We were doing some serious skiing, so we used fanny packs to keep our shoulders free.  We skied into an avalanche, but managed to get to an island of safety and not get swept away. Even so, I ‘ll never forget the sound of it, the loud CRACK! and the hissing of the wind and snow as it swept down the mountain below us. I realized then I might have had to dig out Paul, and I resolved to develop a fanny pack that I could use to carry one of Ramer’s avalanche shovels.” – Patrick Smith, Outdoor Retailer, January 1997

Note: (Mountainsmith lumbar packs are great for skiing in bounds, but if you choose to ski in the backcountry, we recommended using the latest technology to keep you safe from avalanches such as a three strap backpack like the Mayhem 35.)
A view of one of the original delta compression straps on a mountainsmith lumbar pack
One of the original Mountainsmith lumbar packs featuring the Delta Compression Strap, pre-patent approval.

Let us be clear that Smith did not invent the fanny pack, but it certainly inspired his invention.  According to the US Patent #5529230A, a fanny pack has one strap that is fastened around the user’s mid-section.  While Smith wanted to increase the size of the fanny pack to carry an avalanche shovel, there was “a lack of a means to retain the pack in an upright position to facilitate access to the inner compartment or compartments of the lumbar pack.”  Then came the conception of the Delta Compression Strap as pictured here.

A More Ergonomic Carry

Beyond keeping the pack upright as the patent states, the delta compression strap pulled the load closer to the hiker’s body, and into the thoracic region of the back.  Rather than simply pulling the weight away from the user and against the belly, the added strap created a dynamic load carry system. It puts the pack’s load onto the skeletal system, creating an ergonomic and more comfortable carry for the user.  Not only is this great for the backcountry skier that must keep a tight center of gravity, but is also a beneficial system for hikers who have back pain.

Securing US Patent #5529230A

One of the original drawings for the patent submission.
One of the original drawings for the patent submission. Source: Google Patents

Through years of work with the patent process, it was determined that Patrick Smith had developed a unique invention that was worthy of patent protection.  Through the use of the Delta Wing Compression Strap, a strap that ran from the upper portion of the pack to the waist belt, the Self-Supporting Lumbar Pack was established.

US Patent #5529230A was awarded on June 25, 1996, and Mountainsmith has been developing lumbar packs ever since that have utilized the technology.

The Omni Belt

While the purpose of the Delta Wing Compression Strap was to keep a large fanny pack upright, the ergonomic benefits were realized by the Mountainsmith design team.  Based on the success of the lumbar packs, the team developed the Omni Belt, a waist belt for backpacks that would feature the Delta Compression Straps.  The effect of this added feature was that the pack’s weight carried more comfortably than ever, once again loading more of the weight onto the waist belt and the user’s skeletal system.  Today, Mountainsmith backpacks that utilize the Delta Compression Straps load up to 70% of the pack’s weight onto the waist belt when fitted properly.

Modern Use of the Delta Compression Straps

Mountainsmith Delta Wing Compression Strap
The Delta Compression Strap as seen on the Mountainsmith Apex 80

The technology established by Patrick Smith lives on today in many of Mountainsmith’s products. The Delta Wing Compression Straps is used on larger lumbar packs and backpacks, in conjunction with the Iliac Crest Shelf Cup system and Lumbar Control Point Pad. This trio of technologies, combine to create on of the most comfortable and ergonomic fits offered for backpacks in the outdoor industry.


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