Ms. l is a 78-year-old who underwent surgery for internal fixation of an intertrochanteric fracture of the (l) hip 3 days ago. for the next few weeks she must remain non weight-bearing on the operated side and has begun to use a walker for ambulation. she is able to walk for short distances around her hospital bed but is not yet able to rise from a chair to standing. according to the icf model, the inability to stand from a sitting position is classified as a(n):