4.—(1) For the purposes of Article 82(2) and Article 83 or, as the case may be, 84 whether C has limited or severely limited ability to carry out daily living or mobility activities, as a result of C’s physical or mental condition, is to be determined on the basis of an assessment taking account of relevant medical evidence.
(2) C’s ability to carry out an activity is to be assessed—
(a)on the basis of C’s ability whilst wearing or using any aid or appliance which C normally wears or uses; or
(b)as if C were wearing or using any aid or appliance which C could reasonably be expected to wear or use.
(3) Where C’s ability to carry out an activity is assessed, C is to be assessed as satisfying a descriptor only if C can do so—
(a)safely;
(b)to an acceptable standard;
(c)repeatedly; and
(d)within a reasonable time period.
(4) Where C has been assessed as having severely limited ability to carry out activities, C is not to be treated as also having limited ability in relation to the same activities.
(5) In this regulation—
“reasonable time period” means no more than twice as long as the maximum period that a person without a physical or mental condition which limits that person’s ability to carry out the activity in question would normally take to complete that activity;
“repeatedly” means as often as the activity being assessed is reasonably required to be completed; and
“safely” means in a manner unlikely to cause harm to C or to another person, either during or after completion of the activity.