The use of wearable sensors in consumer health and medicine is a rapidly developing topic of interest. The main purpose of the series of studies in this thesis is to identify novel uses of technology that can provide clinicians and scientists clinically feasible, low cost approaches to obtain meaningful information about functional limb symmetry in patients with knee injuries.
In Study 1, individuals undergoing knee surgery were evaluated as they walked and stepped down onto a force platform in a manner similar to how one would step off a curb to cross a street. When subjects stepped onto their uninvolved leg, peak vertical ground reaction force was greater and occurred earlier than when stepping onto their involved leg. Asymmetries were greater in those with higher quadriceps neuromuscular impairment.
In Study 2, the reliability and validity of using wearable accelerometer sensors was evaluated for estimating single leg vertical hop height in healthy people and individuals after ACL reconstruction surgery. The reliability and concurrent validity of using accelerometers to estimate single leg hop height were excellent, and were similar for healthy and ACL-reconstructed subjects. Error for this method was low, in particular when the accelerometer was worn at the lower leg. Asymmetry in hop height was greater in those with higher quadriceps neuromuscular impairment.
In Study 3, wearable accelerometers were compared to a system of motion capture cameras and force platform as a method to assess functional movement asymmetry in healthy people and individuals after ACL reconstruction. While walking and stepping down, accelerometers worn at the waist were able to detect underlying movement asymmetry when it exists in people after ACL reconstruction. Acceleration at the waist was strongly associated with vertical ground reaction force and moderately associated with knee extension moments. Collectively, these studies provide evidence that functional movement symmetry can be measured with simple, inexpensive methods that can be used in a variety of clinical or field-based settings.