hiking boots/shoes on rtw

"can i buy a really light hiking boot or will this just crush my ankles while carrying up to 20kg in Patagonia?"

Depends partly on how strong your ankles are. I assume that if your are taking on a trek with 20kg, you know what you're doing, so should be able to make your own assessment of this.

On the other hand, boots that give ankle support, especially with rough terrain and under heavy load, is partly a matter of insurance/risk. I was once trekking for 3 weeks without accident, then twisted an ankle back in a city when I inatttentively slipped off a curb -- dumb carelessness.

So you have to balance your fitness and strength (of ankles), degree of care you're prepared to take, quality of the ground underfoot, amount of risk you enjoy. Have you tried loading up your pack then taking a hike with light shoes? Maybe you just have to see how your ankles/legs react to the load and stress, and then make your decison that way. Walk for 2-3 hours: it's the reaction under fatigue conditions that's critical.

I don't see why boots good for open country suddenly hurt your feet on streets. Good boots shouldn't have that effect.

"what is your opinion on walking poles?"

I have an opinion, but i don't know if there is any clear-cut objective information about them. Again, a lot depends on personal factors that are different for different people -- fitness level, strength of knees, etc.

I own Leki poles with telescoping shaft, so I can store them easily in my pack when not using them. I was advised by the salesman that models with spring-mounted heads are expensive nonsense.
If you intend to use poles as weight support, then use two poles or none at all. Only one pole messes up your balance and posture. Sometimes I carry just one, not for support but for fending off curious stray dogs, poking around in underbrush etc. Two poles plus ground sheet makes a decent improvised windbreak in open ground.

I'd spent years not using poles, and I still have problems finding the right walking rhythm and I usually don't bother. Also, when I'm on open terrain I am more comfortable with my hands free.

I find them at no time useful if I carry only a daypack.

With a 15-18kg load, it depends on circumstances.

I don't find them useful when I'm heading upwards and they generally just get in the way. You have to place them in such a way that they don't even take your weight, which is the reason for using them in the first place -- perhaps if I'm very tired, but then all you accomplish is take the weight off legs and back and transfer it to arms and shoulders. Sooner or later you pay the price.

Heading downwards on a steep gravelly trail, negotiating wet rocks over a stream or traversing steep snowdrifts, then they have some practical value for me as extra balance. Some of this may be psychological -- nothing wrong with that, by the way.

I just checked your link -- it brought mew to a Meindl shoe. Correct?

I have a Meindl brand shoe with a flatter sole and even less ankle support than the model pictured. Important that the sole is reasonably stiff, but it did me fine with 12-15 load as long as the trails are well-defined, and not loose underfoot.
Personally, I think a shoe of that sort is a decent compromise, although on average I'd be wary of it being adequate for rougher terrain, loose ground, and with 15-20 kg load. That's when I use a trekking boot (also Meindl). But that's where your personal assessment of your own abilities has to come in.

Hi, I am from Chile - good choice to go to the Patagonian Andes (-:

But remember if you are in Patagonia, you are not in a "hot" country! The weather can change a lot. You can get hail and snow even in summer and especially if you are deep South, Torres del Paine for example, it can get REALLY muddy even on not so difficult paths. It happens every time I go . . . Also, there is a lot of murraine sometimes (sorry, I don't know if this is 100% OK English - I mean kind of loose little rocks and stones that you get before 'real' mountain starts). So from personal experience good ankle support like oldpro says is smart. You should also remember that if you are in a wild place, the hostels are expensive to eat there and pretty basic so you maybe carry a lot. It is no way like walking in France or Switzerland. More than 15-20 kg if you are out for a few days esp. if you have a tent.

You should buy everything before you go. Gear in Chile and Argentina is BAD (unless you know where to go, and there are not so many good places) or VERY EXPENSIVE. Walking poles, I don't know. In Patagonia itself, useful but not essential based on what I know. Good for helping you jump over very big wet muddy pools!!! Anyway, a good pair is so light you should not lose much to travel with these. Black Diamond flick lock poles are nice, I have two.

If you want to go further north and try walking at high altitude, for example near Mendoza or Santiago, then you definitely need walking poles. I don't like walking poles so much, so I left mine at home on my first altitude trek, which was very stupid idea.

Good luck and enjoy some of the most beautiful scenery in the world!!

As #1 says it depends on you. I probably have wimpy feet, blisters an all, yest I have never had a problem with ankles. Neither backpacking or when playing sports in school.

Saying that back in 01-02 I took my high top leather boots because I spent a couple months trekking in nepal, besides SEAsia and South Asia. Sadly it was not due to comfort but the heat. I probably used my boots for 15 per cent of the trip, the majority of that while trekking. Considering the space in pack of the boots I made a change this time. Took sandals and a pair of the low top trekking shoes (Vasques) which worked great for the trekking I did and took up a lot less space. Although I still found that I am wearing sandals for over 3/4 of the trip. Not because UN-comfotable walking shoes but do to the heat when not up in the hills. This will be how I pack in the future.