what-when-how
In Depth Tutorials and Information
to Bleck.
23
Bleck classifies the levels of ambulation as
non-walker, therapy or exercise walker, household
walker, neighborhood walker and community walker;
23
in which children younger than 2 years of age could not
be classified. This classification has been extended into
a 9-point scale (1: non-walker older than 2 years of age;
2: therapy walker with the use of crutches or canes; 3:
therapy walker without the use of crutches or canes;
4: household walker with the use of crutches or canes;
5: household walker without the use of crutches or
canes; 6: neighborhood walker with the use of crutches
or canes; 7: neighborhood walker without the use of
crutches or canes; 8: community walker with the use
of crutches or canes; 9: community walker without the
use of crutches or canes).
24
In general, rehabilitation
strategies should focus on the achievement of commu-
nity walking in the mildest type of OI (type I), whereas
in OI type II B exercise walking, in OI type III exercise or
household walking and in OI type IV household or com-
munity walking should be possible.
25
Next to general mobility, analysis of direct gait pat-
terns in patients with OI is scarce. The study of Graf et al.
used a 14-camera Vicon Motion Analysis System for gait
analysis in ten children with OI type I and 22 age- and
gender-matched healthy controls. The results demon-
strated abnormal gait parameters including increased
double support, delayed foot off, reduced ankle range of
motion and plantar flexion during third rocker, along with
greater ankle power absorption during terminal stance
and reduced ankle power generation during push off.
The functional assessment scores of the OI group (PODCI,
Faces Pain Scale-Revised and the Gillette Functional
Assessment Questionnaire) were similar to the control
group for basic mobility and function, but were lower than
their peers in the sports and physical function category.
26
probably the primary causes of the decreased aerobic
capacity in children with OI type I. However, it was
unclear whether the reduced VO
2peak
and muscle force
were a consequence of a hypoactive lifestyle or a spe-
cific consequence of the impaired muscle collagen
synthesis. So in most cases, children with mild to mod-
erate forms of OI seem to be primarily restricted by a
reduced aerobic capacity and reduced ability to gener-
ate muscle force, rather than by cardiopulmonary limi-
tations.
14,19
Evidence for circulatory abnormalities was
not found.
In addition to the direct effects of the disease, for
example impaired bone development and impaired
skeletal, cardiac and pulmonary muscle tissue, there are
striking indirect factors which could affect the physical
fitness of these children. Fear of fractures is the most
frequently heard explanation for not participating in
sports and other physical activities, often promoted by
parents and physicians in the interests of safety.
20
This
protective attitude may result in an unnecessarily hypo-
active lifestyle and physical deconditioning.
In 2008 van Brussel et al. randomly studied the
efficacy and safety of an individual and supervised
an exercise training program in 34 children with OI
types I and IV.
19
The authors found a 12-week exer-
cise training program in children with OI types I and
IV to be safe and effective. Patients allocated to the
intervention group received a graded exercise pro-
gram consisting of 12 weeks (30 sessions) aimed at
improvement of exercise capacity and muscle force,
whereas patients in the control group only received
usual care. Patients allocated to the intervention group
were instructed to attend exercise sessions twice a
week held at a local physical therapy practice for 12
weeks consecutively and to perform home-based
exercises once a week, starting after the sixth week
of the intervention. The 45-minute sessions included
a 10-minute warm-up period. Ten minutes of aero-
bic training (on the basis of an intensity ranging from
60% to 80% of their baseline peak heart rate) was fol-
lowed by 15 minutes of free play and muscle training,
and thereafter another 10 minutes of aerobic training
was performed. The session ended with 10 minutes
of cool down exercises. The authors observed statis-
tically significant improvements in aerobic capacity
by 18%, muscle strength by 12% and clinically rele-
vant improvements in perceived fatigue (19%).
19
The
described training program can be an important way
of increasing fitness in children with OI, because par-
ticipation in regular sport activities is not an option
for most children because of their reduced exercise
capacity and their increased fracture risk.
The general recommendation for children and young
people with mild to moderate types of OI is to actively
encourage a physically active lifestyle, although contact
Physical Fitness
Although children with mild and moderate forms
of OI are in general walkers, fatigue, diminished exer-
cise capacity and exercise intolerance are frequently
reported to limit their activities of daily living.
10
To
date, two studies have been accomplished regarding
physical fitness in OI.
14,19
The study of Takken et al.
was the first to study the health-related physical fitness
and cardiopulmonary function in 17 children with OI
type I.
14
Cardiopulmonary function at rest was within
normal ranges; however, vital capacities were reduced
when compared with normal height for age and gender.
Furthermore, aerobic capacity (expressed in VO
2peak
and VO
2peak/kg
) as well as muscle strength were sig-
nificantly lower than that of peers without OI (
p
≤0.01
for all values), whereas fatigue was related to proximal
muscle weakness and a reduced peak oxygen consump-
tion (VO
2peak
). Muscle atrophy and deconditioning are
