I watched first for this brief a video about how to properly pick up a box, both because I wanted a reference to make my character's motion more believable, and because I felt if my character was going to do something, they'd better do it properly.
Despite the referencing for the proper method for picking up boxes, I decided my character would struggle to pick up the box, first lifting with his legs, whilst the box stayed on the ground, so their lower back would raise up, and then have the character lift the box up with their back after struggling. I wanted the weight of the box to be evident in this, and the bent line of action, where the weight of the box is weighing down the characters body, creating an arc.
I was happy with the character's approach to the box. I felt the bending down motion to be quite jagged, but the raising motion and struggle with the box is quite fluid, and I was happy with the release of energy when the character manages to pick it up, and how the character has to bend to accommodate the new weight.
I didn't like the characters final movement to a more stable position, and felt the slide into the position to be a bit of a cop out. So I re did this last movement, making the character put more effort into this action to demonstrate more the weight of the box, overall making it more believable.