Most of the time when someone hears the term "granny" they think: nurturing, fragile, loving... they may even picture a sweet old lady in a rocking chair.

But they might not think of a grandmother passionately voicing her thoughts and opinions as she dances with her fellow grandmas down the streets of San Francisco.

Veteran filmmaker Pam Walton's latest documentary follows the activist group Raging Grannies in their quest to bring attention to injustice and inequality, while exploding stereotypes and fighting ageism.

Independent producer Catherine Girardeau has the story. To listen press play on the audio player above.