Possible Clues:

• As much as one limb can hold
• Big baby, maybe
• As much as you can carry
• Two or three bags of groceries, say
• A lot to carry
• Carrying capacity
• With an extra hand it's causing harm, as it is it amounts to what's on a limb
• Cockney fell – 'ow much was 'e carrying?
• Grocery load
• A lot to carry is commonly dangerous