Crippled Avengers (1978) on Netflix

A wealthy kung fu expert, who is turned bitter and evil by the slaying of his wife and the loss of his son's hands, bullies a town through terror and force. They find pleasure and satisfaction by crippling those who stumble in their way. Four of those who are crippled, a hawker who is blinded, a blacksmith made mute and deaf, a drifter who loses his legs, and a fighter who loses his sanity, band together to use their disabilities to the best of their advantage. The four are tested time and time again, and demonstrate their strengths and abilities.