Throughout Henry Winkler's award-winning acting career, his vital, German-born mother, Ilse, was always present, applauding proudly.

But following a stroke in her 70s, her arms became so stiff from a condition called upper limb spasticity that "she couldn't even dress herself," recalls Winkler, who watched her become dependent on caregivers until her death a decade later. Today Winkler, 65, is lending his star power to help the estimated 1 million Americans affected by the condition, serving as spokesperson for Open Arms: Raising Awareness of Upper Limb Spasticity, which highlights a promising new treatment using Botox. "I met a woman who couldn't move her arm at all," says Winkler. After treatment, "she was able to hug her daughters for the first time in two years." Best known for his role as Fonzie on the 1970s-era sitcom Happy Days, Winkler is a regular on the USA Network comedy Royal Pains. But traveling the country campaigning to help alleviate stroke victims' suffering has a special place in his heart.

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