Backpack is a cloth sack or bag carried on back and two straps that go over the shoulders secure it. There are also these modern Backpacks that have only one strap to go over the shoulder. These are mostly and commonly used by hikers and students or sometimes, backpacks for special purposes like by the swimmers as the best swim bag.
In general there are three main kinds of backpacks: The first, without any frame or frameless; Second, External frame packs; And lastly Internal frame packs. A pack frame mainly supports the pack and distributes the weight of its contents across the body more appropriately. This is done by transferring most of the weight to the legs and hips.
This is the simplest backpack design constituting of just a bag attached to a set of shoulder straps. The frameless kind is used for general transportation of goods and have variable capacity. This type of backpack is mainly given to hikers and swimmers to carry lightweight materials.
External frame packs
These types generally have their frame made of aluminum, other lightweight metal alloy, or plastic polymers with a system of straps such that it prevents the contact between the backpack's frame and the user's back.
It was designed for carrying more heavier loads (generally starting from 20 pounds and going up till 40 pounds) to be useful for mountain climbing.
Internal frame packs
The internal frame packs were invented quite recently in the twentieth century, in the year 1967 by George Lowe who founded LowePro, a backpack company which mainly pioneers in skiing backpacks and associated products. Internal frame packs have a large clothing (fabric covering) around the frame constituting of strips of aluminum, titanium or plastic. The frame is made to fit the wearer's back closely and tightly so as to reduce the chances of shifting of the load so that the wearer can participate in activities that involve the movement of upper body like skiing and scrambling over rocky surfaces or swim hiking.
Swimming backpacks or swim team backpacks are used for keeping in swimming accessories and swim kit. It is also used for Swim Hiking, a recreational activity which combines hiking with outdoor swimming. These bags are made waterproof so as to protect the accessories inside and the backpack too. Swimming backpacks have many compartments to fit in the different accessories needed for swimming. Sometimes these backpacks even have mesh inserts to aide in drying. These are used by long distance swimmers as well as by those who compete in tournaments and other competitions. There are many different companies who sell these swim team backpacks with additional facilities such as Ipod pockets, a compartment for drying and goggle saver pouch etc.
Companies which sell Swim team backpack and associated products
- TYR Alliance
Backpacks may generally be associated with students or hikers but there are some other backpacks too, which are used for different purposes like the swim team backpack which actually serves as a multipurpose backpack with lots of facilities.