Ex N' Flex EF250 Leg Exerciser. Ex N' Flex EF100 Arm Exerciser. Applications Hemiplegia, Quardriplegia Multiple Sclerosis, stroke recovery, accident recovery, Parkinson's Disease, Alzheimer's Disease, post surgical, exercise for the elderly. These passive/active machines allow the user to actively exercise when strength is available or passively, rotate limbs to keep them moving. A digital feedback indicator measures your progress.