Hiking backpacks come in several different types. Generally a hiking backpack can have an internal frame or an external frame.
An internal frame hiking backpack has the structural part of the frame integrated into the pack itself. These packs range in size and are often expandable. Many internal frame hiking backpacks have a couple of exterior pockets, but have a large central compartment to carry most of your gear. Compression straps along the sides allow you to adjust the height of the pack to stuff more gear. The trick to packing an internal frame hiking backpack is to use many different bags inside the pack. Rolling an entire set of clothes together will make it so that you don’t have to unload the entire pack each time you need to change your clothes. You will also want to balance your pack, making sure that it is not too heavy on top. Keep things like your rain poncho, first aid kit and daytime snacks in the outside pockets, so that they are easily accessible. Pack your ground cloth, tent and sleeping bag last, as these will be the things you’ll definitely get out of your pack first before you dig into the remaining contents. Balance the load of the entire pack so that the weight is evenly distributed side to side as well as from top to bottom. Be careful not to overload the attachments points on your pack with heavy water bottles and gear that will make a lot of noise as this will make your hike less enjoyable as these things rattle around when you’re hiking.
External frame hiking backpacks usually have a lightweight metal frame that the pack is strapped to. This frame gives the external hiking backpack its rigidity and strength. You might think that the rigid frame would be uncomfortable, but generally it is more comfortable. External frame hiking packs often have multiple pockets and compartments, allowing the hiker to pack different items in different locations to better balance the weight. Most commonly, the external frame is open on the bottom, allowing the hiker to strap on a sleeping bag and tent. Use the external pockets for snacks, rain gear, first aid kits, and other equipment that you will need on the hike. Because the bottom of the pack is open and used to strap on the sleeping bag and/or tent, you don’t have to be concerned about getting the rest of your gear dirty from these items if you are on a multi-day hike, and need to store this gear after each night. Because the frame is rigid, the pack size is generally fixed, so compression straps that are common on the internal frame hiking backpacks are not usually found on external frame packs.
What is common between both styles of frames in hiking backpacks are shoulder and waist straps. These are usually adjustable and can be tightened or loosened to fit the hiker. While there is some adjustment to these straps, you will want to find a hiking backpack that generally fits your overall height. Have someone help measure your back from your waist (just above the hip bone) to the base of your neck. More than 20” is “Tall” or “Large”, 18-19” is “Regular” or “Medium” and less than 18” is “Small”. It is important that you do not get a pack that is too tall or too short, as these will cause you a significant amount of discomfort on your hike.
One final note about strapping on your pack – Take some care in how to put your pack on your back. First, get the pack on your back then bend over at the waist. Slide the weight up on your back and tighten up the waist strap. Afterwards, tighten up the shoulder straps. All of the weight of the pack should be around your hips. The shoulder straps should only keep the pack from falling backwards. If you can completely remove the shoulder straps without the pack sliding down, then you’ve done it right.
Your choice of hiking backpack is really a personal decision. Do what you feel is most comfortable. If you are comfortable then you will enjoy your hiking backpack.