Causes. Leg length discrepancies can be caused by poor alignment of the pelvis or simply because one leg is structurally longer than the other. Regardless of the reason, your body wants to be symmetrical and will do its best to compensate for the length difference.
Date of Onset. When the Social Security Administration (SSA) refers to a disability applicant's Date of Onset, they are referring to the date that a Social Security Disability applicant became disabled. When you fill out your Social Security Disability claim forms, you will be asked to provide the date your disability began.
(This maximum gets you to 12 months before your application date, plus five months for the waiting period, so your earliest established onset date is 17 months before the application date.) In turn, the earliest you can become eligible for Medicare is two years after you apply for Social Security disability.