abasia abasia abasia (from greek: a-, without and basis, step) is the inability to walk owing to impairment in motor coordination. abasiadifferential diagnosischoreic abasia, paralytic abasia, spastic abasia, trembling abasia the term covers a spectrum of medical disorders such as: choreic abasia: caused by chorea of the legs paralytic abasia: caused by paralysis of the leg muscles spastic abasia: caused by spastic stiffening of the leg muscles trembling abasia: caused by trembling of the legs abasia is frequently accompanied by astasis, an inability to stand, see astasia-abasia.