/ External Frames
Hip Belt (Women)
This is really a feature found most often on IF packs. Compression
straps basically allow you to compress the size of the pack
around the loaded equipment to provide a tight and stable "package".
If you're carrying gear on a hot summer weekend, you might not
carry as much as you would on a late autumn trip. You may not
have enough equipment inside to fill the pack to its full dimensions.
Compression straps close up this extra space. They're most often
located on the sides of the pack - a simple strap and buckle
arrangement. Some IF packs with a single compression strap on
each side, or as many as three. Some packs may have compression
straps that run over the back of the pack as well or even straps
that pull vertical rods for even compression. Same theory, different
Sleeping Bag Compression Straps
A few IF pack manufacturers also include vertical compression
straps and buckles that run over the sleeping bag compartment.
These straps can be connected when the sleeping bag is stuffed
half-way into the sleeping bag compartment and tightened down
to compress the remaining part of the sleeping bag, making it
easier to stuff. Nice feature, especially if you're trying to
get a large winter synthetic sleeping bag into the compartment.
The straps can also serve double duty by providing another means
of carrying a tent or sleeping pad securely on the outside of
Most larger packs may have an additional adjustable buckle and
strap arrangement that connects the shoulder straps together.
The sternum strap is designed to distribute weight across the
front of the chest. This can relieve pressure at the front of
the shoulders and generally make the pack marginally more comfortable
to carry under load. Sternum straps also pull the straps closer
to the center of the body, allow increased arm flexibility and
range of motion, and prevent straps from slipping off the shoulder
when leaning over or scrambling over rough terrain.
Better pack designs will also fashion shoulder straps to more
naturally follow the contours of the body. "Articulated"
shoulder straps generally have a built-in curvature that follows
the natural route of the strap over the shoulder and down the
side of the body. Obviously, this design is more comfortable
than a strap that is simply a straight piece of nylon covered
foam. On packs designed for women, shoulder straps are also
sometimes designed to allow for natural body curvature at the
Load Stabilization Straps
Found almost exclusively on IF packs, load stabilization straps
are supplementary straps that run from the top of the shoulder
strap up to an attachment point on the pack around ear level.
These supplementary straps allow you to adjust the distance
between your back and your pack. On uphill pulls were it's advantageous
to have the weight close to your back, these straps can be tightened
to pull the top of the pack close to your body. On downhill
strolls, the straps can be loosened to move the center of gravity
more towards the middle of your body and the pack. Some also
like this feature during the summer, when the straps can be
loosened to provide some ventilation between the back and the
pack. Some pack designs might also include lower load stabilization
straps from the area of the sleeping bag compartment to the
hip belt. These straps are designed to minimize pack "swaying"
at the bottom of the pack.