Acupuncture help with pain muscle tension or some neurological symptoms but it is not well established as a treatment for increasing muscle strength itself. If your goal is to improve muscle strength Resistance strength training and physiotherapy are generally the main approaches. Acupuncture may sometimes be used alongside rehabilitation particularly when pain is limiting exercise. If weakness is new, progressive one sided or accompanied by numbness difficulty walking or loss of bladder bowel control seek medical evaluation promptly. If you tell me which muscle or body part is weak and the cause e.g injury, stroke, nerve problem, age related weakness I can explain whether acupuncture has evidence for that specific situation