Analysis of Running Biomechanics and Plantar Pressure Distributions in Subjects with
Chronic Ankle Instability
Morrison, KE
Lateral ankle sprains are common injuries in athletic activity. Although most will resolve
with conservative treatment, others develop Chronic Ankle Instability (CAI), a condition
associated with persistent pain, weakness, and instability. Because of an increase in
prevalence of CAI, considerable attention has been directed towards understanding the
underlying causes of this pathology. Despite the amount of research conducted in this
area, analysis of individuals with CAI during dynamic conditions is limited. A detailed
kinematic and kinetic analysis of the stance phase of dynamic movement patterns may
give greater insight into the stresses placed on the foot and ankle complex in CAI
subjects and how they differ from other populations. The aims of this study are: (1) to
determine if there are kinematic and kinetic differences at the foot and ankle complex in
the running mechanics of subjects with CAI; (2) to determine if there are kinematic and
kinetic differences at the foot and ankle complex during a forty-five degree cutting
maneuver in subjects with CAI; and (3) to determine if there are differences in dynamic
plantar pressure distributions at the foot during a running gait in subjects with CAI. To
address these aims, a three-dimensional motion analysis and plantar pressure
assessment will be conducted on 45 subjects. The subjects will be specifically recruited
and divided for comparison into three groups: 15 subjects with chronic ankle instability
(CAI), 15 subjects who have a previous history of only one lateral ankle sprain and
never experienced recurrent symptoms (no CAI), and 15 control subjects who are
without a history of a lateral ankle sprain (Control). A range of kinetic and kinematic
variables will be extracted using techniques developed in previous studies. The
variables will be analyzed to determine if there are differences between each subgroup
during a running gait and/or a cutting maneuver. Accurately assessing foot and ankle
mechanics can give insight into the pathogenesis of CAI. Once determined, future
intervention studies can be performed to reduce the incidence and severity of acute and
chronic lateral ankle injury.