Clinical practice demonstrates that musculoskeletal and
neurological disorders can have a substantial impact on gait
quality. In order to determine the severity of impairment as well as
to evaluate therapeutic interventions, the ability of quantifying
gait is of great importance. Objective gait analyses are commonly
achieved by using sophisticated measurement tools such as
marker-based motion analysis systems. However, these systems
are dependent on a laboratory and associated with high costs,
restricting their use for most clinical practitioners. Recently,
researchers have considered accelerometer-based measurement
systems as a possible alternative to the expensive and time
consuming laboratory assessments [1,2]. Tri-axial accelerometers,
for example, detect changes in velocity in three orthogonal axes
and are often used to measure accelerations of a reference point
close to the body’s centre of mass (CoM).
Analysing the motion of the CoM can be used as a simplified
concept to look at human locomotion [3]. CoM displacement might
be seen as the result of all forces acting upon the body
[3]. Neurological or musculoskeletal disorders might alter movements
of body segments and thus influence the motion of the CoM
[4]. Based on data measured by a motion capture system, previous
research reported differences in CoM displacement when comparing
normal with pathological gait. Children with myelomeningocele,
for instance, showed an increased lateral and vertical CoM
displacement [5]. Findings of another study investigating gait in
subjects with myelomeningocele indicated that vertical CoM
displacement was related to energy consumption, assessed by the