Ulla Werlauff Methods to assess physical functioning - Danske ...

have lost their independent sitting balance cannot score on the scale. This results in a considerable
floor effect among weak patients, and we found that almost half of our patients could not perform
any task on the scale. This was not only so in adult persons, but also in weak children. The scale
may be useful for some of the more physical capable patients, but it is a problem that only two
items assess upper limb function, which is done at a functional level that corresponds to Brooke
levels 1 and 2 (able to lift arms and bend shoulders). Consequently, the HFMS is not appropriate as
an outcome measure in a total population of patients with SMA II.
Motor Function Measure
The MFM was developed for neuromuscular disorders and is as such a disease-specific scale.
However, targeting all neuromuscular disorders makes the scale more generic. The various
disorders are very different in origin and in phenotypes, meaning that the diseases may share similar
problems at activity level, but very different problems at impairment level. As an example, two
persons may have problems in walking – one because of a progressive dystrophy resulting in loss of
proximal muscle strength, the other because of neuropathy resulting in loss of distal muscle
strength. The scale assesses motor function in three dimensions. None of the dimensions are
targeting upper limb function, but motor performance from both upper and lower limbs are included
in the proximal and distal dimension. The distal dimension contains six items that assess distal
function in upper limb, and only one item that assess distal function in lower limbs. We chose to
omit the lower limb item to test the dimensions applicability to assess upper limb function in SMA
II, and found that the subscale could then not discriminate among the strongest patients. This is
likely due to the fact that none of the six items measure antigravity function of the elbow or
shoulder. With such items included, the scale could properly be more sensitive and of more interest
as an outcome measure for upper limb function in SMA II. Since the MFM measures the ability to
perform activities that are not directly related to the patient’s daily function the scale is of more
limited use when the patient’s daily function is assessed. However, the various tasks can be
“translated” to daily activities; as an example do the ability to move one finger across squares,
indicate that the patient has capacity to use electronic equipment e.g. to drive his wheelchair or use
a computer.
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