Sorry if this isnt quite the answer you are looking for but...
The problem I see with normal adjustable hiking poles is they just are not tall enough or strong enough against the forces being applied against them. I would recommend using a solid wood or even better ---Bamboo Poles, they are very light and are excellent hiking staffs.
Both my Bamboo Hiking Staffs are just over 5' tall and I plan to make the next set around 66". I always insert a wooden dowel plug into the top of the staffs and secure with non expanding wood glue and then add screw in Eye rings to the top. This allows my Bamboo Staffs to double as Tarp/Rain Fly posts.
Most store bought trekking poles are = or less than 55". This may be possible to lift a hammock off the ground with decent tension but the problem is they are not designed for this kind of load. This is why I recommend the bamboo staffs. They are VERY light weight when fully seasoned and extremely strong. The drawback is they are not collapsible. Its a trade off for gaining the strength of the bamboo. It is possible to make the bamboo poles collapsible by using pool stick thread connectors but it is a sacrifice to its overall strength.
Anyways sorry to tangent my answer so badly. I hope some of this may be of some help to you. If you ever need any advice or help working with anything bamboo I would be more than happy to share my expertise. If you have trouble finding bamboo just shoot me a message and ill take care of ya.
Bamboo Trekking Pole Tutorial