Research into ankle injury prevention Flashcards
Give some facts about the epidemiological findings on ankle sprain injuries
second most commonly injured body site in sport
inversion sprain is most common type of ankle injury
only 15% of people seek medical attention
when would a person be considered to be at increased risk of ankle instability
when they have suffered 5 or more sprains
what are the two aetiologies of ankle inversion injury
incorrect landing posture:
slightly inverted or supinated. therefore GRF acting on lateral edge of the foot, pointing to the medial side so doesn’t pass through ankle joint centre. this causes a vigorous inversion torque.
Delayed peroneal reaction:
takes 60-90ms whereas injury occurs within 50ms
During the research phase, how was the mechanism of ankle sprain investigated
video analysis, firstly of an injury which occured during a biomechanics experiment
then of injuries occuring at the Bejing Olympics and in tennis events
Which kinematic variable was outside of the normal range and considered to be the likely cause of injury
rapid inversion velociity
all were above 500m/s
why was a device using pressure sensors to calculate the GRF abandoned
because during the injury mechanism when the foot rolled over the lateral edge no data would be recorded by the pressure sensors
what is actually used to monitior the ankle and detect when injury is likely to occur
uni-axial gyrometer
why was the semi-rigid brace design, as a method of prevention discarded
high cost of the smart material
worries about damage to the skin if the material leaked
What is used as a method of prevention of the injury
myoelectric stimulation to the peroneal muscles
where are the stimulators located and what size electrode is used
Why were these decisions made
upper 1/4 of the lateral shank
small sized electrodes
because the combination of these two gave the biggest reduction in inversion velocity
justify the reasons for the timings used in the anti-sprain system
injury is known to occur within 50m/s, and probs at 40 m/s
also known that it takes 25 m/s from stimulation for the muscles to contract
therefore can allow a max of 15 m/s for detection of the injury mechanism
why is a monitoring system which monitors at 300 Hz required
allow the collection of two data points within the 15 m/s
if both are above the threshold for inversion velocity then the anti-sprain system will be stimulated
