For years, thousands of such porters have crossed the border every day into Ceuta, a Spanish enclave perched on the northernmost tip of Morocco.
But now an initiative aims to ease the burden by encouraging the women -- who are paid to exploit an anomaly in Moroccan law that exempts items carried by pedestrians from duties -- to use trolleys.
"It's less trying than before," said Najat, one of the porters whose back-breaking work has earned them the nickname "mujeres mulas" (mule women) in Spanish.
"It's a good thing, especially for those with health problems," added the mother of two, whose husband is unemployed.
On a hill towering above the Mediterranean between Ceuta and the Moroccan town of Fnideq, Najat, who is in her 40s, waited to pass routine checks at a small pedestrian border post.
Ceuta emerged as a military and commercial port under Spanish rule dating back to the 15th century. Today it has a population of around 85,000, enjoying a degree of autonomy from Madrid.
Najat was equipped with her new wheels.
Welded locally, the device is "much more durable than trolleys sold in the shops", she enthused.
For the past five years, Najat has been entering the Spanish enclave twice a week, arriving back several gruelling hours later with bundles of goods. She makes around 20 euros ($25) for each round trip, delivering the items to merchants; approximately the same cost as her new trolley.
Women transport huge packages at the border in Ceuta. Archive photo: AFP
While goods brought by vehicle from the European Union are subject to import duties at the Moroccan border, items taken on foot are exempt.
Under pressure from NGOs following a string of incidents, including deaths, traders and authorities in Ceuta launched the trolley initiative this month, to complement a raft of other reforms.
At dawn, a group of 100 women were the first to cross the frontier to a commercial zone just inside the Spanish enclave. The zone was built in 2004 to reduce congestion in the centre of Ceuta.
Metal hangars house an array of merchandise: clothes imported from China, cleaning products, basic foodstuffs and decorative items.
'Difficult on slopes'
"The situation is improving, thank God," said 35-year old Touria, a scarf wrapped around her head. She had come to look for food products.
Other reforms include a daily limit on the number of porters crossing the border and alternating days for men and women.
At least four women porters were trampled to death last year, in stampedes at the border post -- the only land frontier between the EU and Africa.
Private security agents have been employed in the commercial zone, paid by local traders and the authorities in Ceuta.
"We will not see any more shameful images on TV," said a security guard, who helps ensure the porters queue for their turn in an orderly manner.
He described the efforts by authorities as "a step" forwards for human rights.
Scrolling through his smart phone, the burly Moroccan showed what he called "images of chaos" taken a year ago, that he said he encountered on a near-daily basis.
"All that belongs to the past," he said.
But he believes more should be done to help the women. "Now we must reduce the weight of the parcels."
The exploitation of porters "began in the early 2000s and hasn't stopped growing since then", Mohamed Benaissa, president of the Morocco-based Northern Observatory for Human Rights, told AFP.
Under heavy rain, Fatima struggled to steer her trolley, piled high with 60 kilograms (130 pounds) of boxes containing a Spanish brand of sweets.
The trolley does not "roll on its own, it must be steered, and it is difficult on slopes", she said. The new measure had "changed nothing".
"Before, I had backache and knee pain, now I have pain in my arms," said the Fnideq resident in her 50s, adding she would prefer to work in a factory, even with lower pay.
By AFP's Hamza Mekouar