Standard CPR is performed with the person in supine position. Prone CPR or reverse CPR is CPR performed on a person lying on their chest, by turning the head to the side and compressing the back.
Non-spinal structural causes of weak legs may include sacroiliac joint pain syndromes and piriformis syndrome. Non-sciatica related sources of weakness in the legs may include diabetes, peripheral neuropathy and various circulatory and neurological conditions.
Low potasium can cause shaky legs. Mysticdoc: Other possibilities can be low magnesium, calcium, vitamin D, vitamin B12, vitamin B6. Other possibilities can be low magnesium, calcium, vitamin D, vitamin B12, vitamin B6.