Warehouse managers will tell you their picking containers are fine. Ask the people carrying them for nine hours and you get a different answer, usually involving the rim.
Ergonomics in picking is not an academic exercise. Handling-related injury costs are real, turnover in order picking is high, and the difference between a tote that is merely acceptable and one that is comfortable shows up in pick rates within a week. The complaints are remarkably consistent across sites, and they are all fixable at the design stage.
Complaint one: the rim digs in
A picker carrying a loaded tote against their body is pressing a narrow edge into their forearm or hip. The narrower the rim, the worse it is. The usual answer is to widen the contact surface — a rolled rim, or a flat top surface a couple of centimetres wide — which costs almost nothing in tooling and changes how the box feels immediately.
The second half of this complaint is about what happens when the tote is set down and picked up again. If there is nowhere to get fingers under the rim, people grab the top edge with a pinch grip, which is tiring and slow. A small undercut beneath the rim gives a proper grip without creating a dirt trap.
Complaint two: it is too deep to reach the bottom
Reaching to the base of a 400 mm deep tote with a straight arm is a shoulder problem, and it gets worse when the tote is on a shelf at chest height. If the pick face involves retrieving small items from the bottom, the depth is a design fault.
Two fixes: reduce depth and increase footprint, or provide a false bottom for the part of the cycle when the tote is part-full. Both are cheap. Both are almost always better than accepting a deep box because it stacks neatly.
Complaint three: you cannot tell how full it is
Pickers glance at a tote to judge whether to keep filling it. Dark grey boxes make that hard, and the consequence is overfilling — which leads to items falling out in transit on a conveyor, which leads to a jam.
A lighter internal colour, or a moulded fill line, solves this for the cost of a colour change. It is the cheapest ergonomic intervention available and one of the most often skipped.
Complaint four: it slides on the conveyor
Not strictly an ergonomics issue, but it is on the list because handlers mention it. A base that is too smooth slides on an inclined belt; a base with a slight texture or a rim that engages the belt tracking behaves predictably. This is worth testing on the actual conveyor rather than assuming.
Weight at arm’s length is the number to watch
The ergonomic literature on manual handling is dense, but for tote design one principle covers most of it: the acceptable weight drops sharply as the load moves away from the body. A 12 kg tote held close is manageable. The same 12 kg held at arm’s length while placing it on a high shelf is a different proposition.
That argues for a compact footprint over a large one, and for grips positioned so the load can be held close. It also argues against very wide totes even when they stack better — a wide box forces the arms out and the shoulders take it.
Design checklist
- Rim: wide enough to distribute load, with an undercut for a finger grip
- Depth: shallow enough to reach the base without straight-arming
- Colour: light interior, or a visible fill line
- Handles: closed grips, radiused, positioned so the load hangs close to the body
- Base: stable on the conveyor, with no lip that catches on transfers
- Stack and nest: verify with gloves on — a tote that is hard to separate is a tote that gets thrown
The one thing to do before ordering
Put samples on the line for two weeks and ask the pickers. Not the supervisor — the people carrying them. You will get a short, specific, entirely practical list, and most of it will be about the rim.
A well-designed corrugated PP picking box is not a premium product. It is a lighter, quieter, more forgiving container than a moulded tote, and it can be die-cut to fit a specific shelf bay rather than forcing the shelf to suit the box. That flexibility is worth more than most of the other variables combined.