Also, if possible could they be used for trekking aswell?
how come we dont tend to see adjustable ski poles though?

Never seen adjustable ski poles, and I've been skiing for years.

They are different to trekking poles, which are usually sprung and adjustable.

Many back country tourers use adjustable poles. Long for skating or diagonal stride & uphill slogs, & short for downhills. There r 2 sorts of lock - a twist & a lever. l think the lever is more robust. You can also get poles with 2 or 3 sections - 3 compress to a shorter length for stowing is a pack, but have more moving parts to break.

http://rei.com/product/757210
http://mec.ca/Products/product_detail.jsp?FOLDER%3C%3Efolder_id=2534374302726247&PRODUCT%3C%3Eprd_id=845524442590937&bmUID=1214885652433
http://mec.ca/Products/product_detail.jsp?FOLDER%3C%3Efolder_id=2534374302726265&PRODUCT%3C%3Eprd_id=845524442545247&bmUID=1214885652440

l do not see why u cannot also use them for trekking poles - just remove the basket.

You will find the poles in outdoor stores or at places like RE l or MEC. Leki & Komperell r two companies that make them. Black Diamond might also.

You do not see them in day to day use because they r heavier, & more fragile, than a standard pole. That is my opinion. l have a pair of adjustable poles, but seldom use them.

If u only ski at the resorts, then l suggest not buy them. If u want a trekking pole for hiking, then buy a pole that is designed specifically for that, with the shocks & all.

You can buy adjustable poles that r designed for skiing or trekking. They will come with little rubber tips that slide over the bottom of the pole.

If l go backcountry touring/winter camping, l still use my standard ski poles that l would at the resort, but l bring one of my adjustables as a spare, in case of broken or lost equipment.

l concur with Powhound. If u r a resort skier, stick to a regular pole. l have several sets of Goode composite poles & they take lots of abuse.

My backcountry poles r adjustable. l prefer Black Diamond. The BD adjuster is easier to use than the Leki or Komperdall poles. Likewise, l spent two winters fixing & replacing the adjusters on Leki & Komperdall poles that came into my shop with ''problems''. In that same time l never once saw a set of BD poles show up in the repair shop with a busted adjuster.

However, avoid anything that has the ''anti-shock'' crap on it. All it is a way for the pole companies to jack up the price & give the purchaser something else to worry about breaking. IMO, they r not worth it. They r not like pogo sticks. So if u do get an ''anti-shock'' set, do not be putting a lot of excess body weight on the pole. They're not designed for big pole planting tricks.

There is very little difference between adjustable ski poles & adjustable trekking poles. Most of the difference is the graphic on the pole. ( l got that straight from the Leki rep.)

l would not go w/ adjustable poles. They break too easy.