Please know that the joints on Malgus have been tightened on this figure. Additionally the final armor/costume on Malgus will cause limitation to just how extreme people articulate this figure (there's just only so far one will be able to bend the figure at it's knees for example). That all said people can help to loosen up the joints on Malgus a bit if you find he's not giving any give at the knees and elbows (but I want to caution that folks should be mindful and only do this if you feel comfortable as you could potentially still break your figure at the joints if you are too forceful).
For the knees
Simply grip on either sides of the knee joint with your thumbs and index fingers (VERY CLOSE TO THE KNEE JOINT I want to add) and start bending it back and forth (like how a normal knee would bend) until you achieve some more articulation flexability.
For the elbows
Simply grip on either sides of the elbow joint thumbs and index fingers (VERY CLOSE TO THE ELBOW JOINT I want to add) and start bending it back and forth (like how a an elbow would bend) until you achieve some more articulation flexability.
Please, please, please be careful if any of you do decide to take a stab about loosening the Malgus elbow and knee joints in this fashion.
Hope this is able to help!
-SideshowAlex