Were your movements formally diagnosed as hypnic jerks? Just wondering if it might be Periodic Limb Movement Disorder.
Hi, welcome to the forum, most people have experienced a sudden jerking movement upon falling asleep, often accompanied by a subjective sensation of falling or twitching. Such occurrences are known as benign hypnic jerks or sleep starts.
Rarely, night starts can become unusually violent, very frequent, or repetitive, and confused for seizures. The phenomenon is restricted to sleep, and always or virtually always in the transition between sleep and wakefulness, and is not associated with other phenomena.
To conclude, you need not worry; it will not harm your body and will wear off over a time. Maintain good sleep hygiene, be positive. I suggest you to consult sleep specialist for more information. Take care and regards.