OVERUSE-INJURY PREVENTION WITH SMART INSOLES
- MASTER GRADUATION THESIS
WHERE DEMAND AND INNOVATION MEET
Military training is known for its high intensity and high performance pressure. Not surprisingly, this causes a large part of recruits to end up with injury. About 3000 recruits follow basic military training each year, of which about 13% end up with one of three most common injuries: MTSS, iliotibial band syndrome and tibial stress fractures. Of those injured recruits, about 8% gets discharged from the military. Besides general intensity of the training, the cumulation of repeated smaller impacts during marches is bound to cause overuse injury.
For years, researchers have gathered evidence of correlation between specific gait biomechanics of individuals and their influence on injury incidence. Using various types of laboratory equipment, such as pressure plates, walkways and treadmills, researchers found strong correlation between parameters like cadence, vertical loading, (time to peak) heel rotation and local peak pressure values and different types of common overuse injuries in the lower limbs. However, laboratory tests often neglect the influence of footwear, distraction and fatigue. In addition, they are expensive and time-consuming tasks.
This thesis aims to study and implement prediction of overuse lower-limb injury among military recruits, using wearable plantar-pressure sensing and biomechanical gait algorithms. The research has been done with the purpose of designing a usable, affordable and accurate injury-prevention tool, increasing both military wellbeing and operability.
THE MILITARY
Military training has proven itself as high injury risk with overall-injury occurrence of 25 to 82 percent (Franklyn-Miller et al, 2014). Marching and walking are key components in military training, but they show highest impact on musculoskeletal injury (Springer, 2010; Jordaan, 1994). Even though acute trauma might not occur during the march itself, every step creates cumulative microtrauma on the muscles and ligaments in the lower limbs (Hauret et al, 2010).
INCIDENCE & MORBIDITY
OLLI’s are generally located in the knee, heel, foot, ankle and upper and lower leg, but sometimes also the hip and lower back are considered for lower limb injury. In the Dutch Defence specifically, most common and impactful OLLI are Medial Tibial Stress Syndrome (MTSS, also known as Shin Splints), Iliotibial band syndrome (ITB) and Tibial Stress Fracture (TSF), together covering about 13% incidence among all recruits (van Rompay, 2011).
RISK FACTORS
Generally speaking, how we all walk and run is based on
the same sequence of biomechanical movements. However, everyone grows into a personalised pattern, mostly based on anatomic build. Determining personal abnormality in gait is a key factor in defining injury-risk. Why do some people endure an injury while others, with the same physical load, do not?
Intrinsic risk factors can be discovered in the field of
anthropometrics (body build), kinematics (human motion)
and kinetics (acting of external forces on a body in
motion) parameters.
INTEGRATED DESIGN
Value-based and technology-based research studies revealed the key part of innovation to lie in assessment software. However, integration of electronics should be compliant with military boots and can therefor not have external components. Using Force Sensitive Resistors and a wirelessly communicating microchip, the insole remains both compact and flexible.
MASTER GRADUATION PROJECT
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