At the foot of a gnarled tree, three men stand, literally, on each other’s shoulders. The burly Rodriguez breathes deeply at the base, puckish Bruno steadies himself in the middle and the winsome, light-footed Diego perches at the top; each handsome face expresses the strain of effort but all three crack a smile anyway.

In Erick Stoll and Chase Whiteside’s tenderly observed documentary, the Alvarez Serrano brothers replace their jailed father Luis as live-in caretakers, looking after their 93-year-old grandmother América in Colima, Mexico. Like their work as circus performers, it’s a tough, precarious balancing act.

A scene in which the boys prepare the chirpily stubborn América for an at-home enema is shot from a distance, the camera gallantly refocusing on the bed sheets drying in a courtyard as the process is carried out, the audio expressing the humour, practicality and gentleness with which these young men treat their grandmother; those who have cared for an ailing loved one will find elements of this family portrait recognisably raw.

Diego is the most sweetly concerned, lavishing her with affection and defending her agency and obvious will to live, while an increasingly frustrated Ro insists they only take care of her because otherwise they’d be locked up for negligence. Bruno, perhaps the most hotheaded of all three, takes América for a walk, berating her for being too scared to stand up straight unaided. Stoll and Whiteside are careful to show that sacrifice does not guarantee sainthood.